TheRailwire
General Discussion => N and Z Scales => Topic started by: nscaleSPF2 on April 21, 2015, 07:47:57 PM
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I think that some of you have seen, or made, something similar to the following:
(https://lh4.googleusercontent.com/-VzNJCPPF0oE/VTWsc9BRg7I/AAAAAAAAA4M/w2w05Di8Zqo/s2048-Ut/IMG_0219.JPG)
(https://lh5.googleusercontent.com/--6lqoqqBer0/VTa9IOKcHcI/AAAAAAAAA68/0vdlYfcD0rw/s2048-Ut/image.jpg)
It's a resin casting from Jason Smith over a Bachmann 2-8-0 chassis. Now, I can tolerate a certain amount of non-prototypical detail, but the motor and frame stick out about 5mm from the back of the cab, which puts it the unacceptable range for me. The mission is to fix this.
The boiler shell itself appears to be pretty close to scale, so the desire is to replace the motor with a shorter one.
Full disclosure on the boiler shell:
1. There were a few voids in the casting that were mostly easy to repair with Bondo (I know, this isn't supposed to work).
2. The shell does sit within a scale inch of the proper ride height. A future photo will show what it took to get to that point.
3. There is a lot of nice detail on the casting. Things like handrails and air lines will need to be added. And the flash needs to go.
4. The casting was warped in both the plan and side views. The "hunchback" effect in the above photos is not an optical illusion. Fortunately, a little heat from a hair dryer together with gentle encouragement by hand corrected the warp.
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Full disclosure on the Bachmann mechanism:
(https://lh5.googleusercontent.com/-WsQsegxmZYk/VTa-cyTB7AI/AAAAAAAAA7k/yUObHE3QYuI/s2048-Ut/image.jpg)
1. Some material had to be removed from the top of the frame to get the boiler to the proper ride height.
2. Some of you probably noticed that the upper fastener that holds the frame together is missing. It came that way from the factory. The fastener just below the one that is missing was also stripped. Don't try to order the plastic nuts that hold the screws from Bachmann. They don't have them. I had to make these myself, out of Delrin.
3. The body of the motor is 20mm long.
4. There is lots of room above the frame for a decoder and extra weight.
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So this is what the inside of the frame originally looked like:
(https://lh5.googleusercontent.com/-BeslGLHjwmc/VTa_0jetq4I/AAAAAAAAA80/mrCKpktJR3w/s2048-Ut/image.jpg)
And here is what I am going to try to replace it with:
(https://lh5.googleusercontent.com/-MGJcL3eSCEI/VTa-czLHCwI/AAAAAAAAA7c/Ae7_Oz97n8c/s2048-Ut/IMG_0216.JPG)
In the photo above, left to right, are a Mashima 10x15mm can motor, a NWSL coupling, a Delrin thrust washer, the stock Bachmann worm gear, and a Delrin bearing/thrust washer. Directly below the motor is a homemade steel cradle, to which the motor will get epoxied. The cradle will be fastened to the frame with a vertical screw.
Never done anything like this before, so we'll see together how it turns out. Stay tuned for further updates.
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Where are you going to move the drawbar pin? Looks like it hangs out quite a bit too...
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Where are you going to move the drawbar pin? Looks like it hangs out quite a bit too...
John,
According to my calculations, the rear of the drawbar pin should be even with the rear of the cab. So I am not currently planning to move the pin. Any part of the frame aft of the pin is going to be removed, though.
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that should work.
you may want to use one of the dogbones in the u-joint package
to allow the motor to sit without having to align it with the wormshaft
roll!
victor
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Looking good! If you need any replacement parts such as the headlight let me know.
Jason
P.S. be sure and adjust the eccentric crank.
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Love the project, but confused here....
What are you planning to do for the worm/shaft bearings (with or without the dog bone connection)? The original design relies on a continuos shaft integral to the motor with no other bearings, or am I missing something?
Like I said, love the project; best, Otto K.
(Modified) Okay, I reread your explanation and should have read closer the first time. So you intend to use one delrin thrust washer? Wouldn't it require two?
I'll be following with interest.
Otto
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Hi Cajonpassfan,
I wondered about the second thrust bearing with the big hole in it.
the thrust can be transferred to the motor...
and the bearing between the worm and motor could be omitted.
.... I had not realized that was how he planned to set it up.
ok skip the dogbone and beardonize the inner bearing.
Roll!
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You mean that one end of the worm shaft will have the little "horn" on it with the two ears, and will be supported
only by sitting in the NWSL cup that is on the motor shaft, and the other end of the worm shaft will ride in
a thrust washer?
I don't see how that will work. That horn ball will only hold the shaft straight in one plane,
so it will pivot in the cup all over the place, I think.
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snip...
I don't see how that will work. That horn ball will only hold the shaft straight in one plane,
so it will pivot in the cup all over the place, I think.
this is how the Atlas loco work when you remove the inner bearings to quiet them.
I would call an engineering type solution
everything stays within the correct dimensions to work....
after all, that ball and matching cup are likely to be close to concentric.
I would do two bearing washers and a dogbone (with the two matching cups)
I like thrust on bearing blocks, not motors.
the dogbone solution takes up some more space and costs more to build.
so there are some tradeoffs.
While both solutions do work, I think it is good to know the strengths of each.
victor
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everything stays within the correct dimensions to work....
after all, that ball and matching cup are likely to be close to concentric.
victor
What Victor said. At least that is how I am hoping this will work. Although there is not enough room in there for a dogbone without a lot of fancy machining.
There will be 2 thrust washers, one on either end of the worm. This will take the axial thrust off of the motor bearings. The thrust washer closest to the motor has a large i.d., which allows for some misalignment between the motor and worm shafts.
Am currently having some difficulty pressing the cup onto the motor shaft, so you may not hear from me for awhile. Apparently NWSL thinks that a Delrin part with a 0.047" i.d. is a press fit over a shaft with a 0.059" o.d. That did not work for me, and I was not able to drill out the hole in the cup while maintaining concentricity between the cup and the shaft...
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Jim,
would it not be better to use a good grade silicon rather than epoxy between motor and cradle. that way you could separate the two if needed, epoxy I don't know.
Carl
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I was not able to drill out the hole in the cup while maintaining concentricity between the cup and the shaft...
Doing this with a drill bit is very difficult (if not impossible). For something like that you would need a set of reamers. It would have been easier to grind down the diameter of the shaft instead.
Are you sure you got the right part? 0.047" is 1.20mm (Minitrix motors use that size shafts) while 0.059" is 1.50mm (more standard size shaft). Sounds like the part you bought is designed for the 1.20mm shaft.
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But the Atlas fix / "Bearden" fix uses a shaft with a hex end on it, in a hex-shaped recess in the flywheel.
That means that at any point in the rotation, there are always 6 sides symmetrically pushing
on the shaft to keep it centered at that end. With the two little ears, at any point in the rotation, the
shaft is held centered through one plane, but can rotate on the axis of the ears in the other. The other thing the Bearden fix
has is a real bearing on the other end of the worm shaft, not just a washer. That bearing provides more length
for the shaft to go through, which helps keep the shaft from pivoting at that bearing.
The 2nd thrust washer with the bigger hole in it isn't going to really touch the shaft, if I understand this correctly. It's
there to take up axial load, not keep the shaft aligned.
I suppose as long as the ball is firmly in the cup, it might work.
I fear the shaft is going to wing around like a jumprope being swung between two children.
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Well, at this point, I'm keeping my mouth shut and my eyes peeled ;)
Otto
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But the Atlas fix / "Bearden" fix uses a shaft with a hex end on it, in a hex-shaped recess in the flywheel.
That means that at any point in the rotation, there are always 6 sides symmetrically pushing
on the shaft to keep it centered at that end. With the two little ears, at any point in the rotation, the
shaft is held centered through one plane, but can rotate on the axis of the ears in the other. The other thing the Bearden fix
has is a real bearing on the other end of the worm shaft, not just a washer. That bearing provides more length
for the shaft to go through, which helps keep the shaft from pivoting at that bearing.
The 2nd thrust washer with the bigger hole in it isn't going to really touch the shaft, if I understand this correctly. It's
there to take up axial load, not keep the shaft aligned.
I suppose as long as the ball is firmly in the cup, it might work.
I fear the shaft is going to wing around like a jumprope being swung between two children.
copied due to page flip...
if that is a nwsl ball and cup, the fit is good and a little grease will make for a long life.
the fit is better than the Atlas hex, smoother, and quiet.
and the floppy issues exist in the atlas units...
you are quite correct that the parts need to be properly made
a close fit for the far bearing/thrust disk and the joint needs to be a close fit.
I do not see a need for the inner thrust disk.
the joint can transfer that thrust to the motor.
and that disk will cause noise problems
the drive train is not as I would set it up.
... and not as you would do,
yet I think it will work.
I need to get back to my ore jenny....
crown trucks are on the way.
(being a SPF for the day...)
and looking forward to this loco in DGLE.
victor
edited because I can't proof read... again
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So here is the new powertrain:
(https://lh3.googleusercontent.com/-J3QM-SWxRtY/VTqtE_nVLTI/AAAAAAAAA-k/hi2o7TqoxII/w1060-h706-p/IMG_0649.JPG)
I suppose as long as the ball is firmly in the cup, it might work.
I fear the shaft is going to wing around like a jumprope being swung between two children.
Max, you can relax now. Not only does it work, it seems to run very smoothly. In spite of the fact that I tried to Loctite the motor shaft to one of its bearings. I think the motor is ok, now. We'll see how it works when all of the drivers and running gear are installed.
I would do two bearing washers and a dogbone (with the two matching cups)
I like thrust on bearing blocks, not motors.
the dogbone solution takes up some more space ...
Victor, it would have been nice to have a dogbone, I agree. But fitting it in this space would have been tight, even if one were to shorten the worm gear.
Are you sure you got the right part? (Pete is referring to the cup/coupler) 0.047" is 1.20mm (Minitrix motors use that size shafts) while 0.059" is 1.50mm (more standard size shaft). Sounds like the part you bought is designed for the 1.20mm shaft.
Pete, according to "Dave" at NWSL, I did get the right part. He claims that the .047" i.d. Will press over the .059" o.d. all day long. I was skeptical, so I got a piece of s/s tubing 2.0mm o.d. X 1.5mm i.d., pressed it into a 2.0mm i.d. cup that came in the NWSL kit, and then Loctited the tube onto the motor shaft. (Note to self: don't press it on too far, or, well, see above).
P.S. be sure and adjust the eccentric crank.
Holy c***, Jason. I didn't notice that before. I wonder how long it's been like that.
Stay tuned for more updates, forumers....
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P.S. be sure and adjust the eccentric crank.
Hmm... Kiz is an eccentric
crank...
(http://bayouline.com/o2.gif)
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Looks great, man. I'm glad it worked out after all!
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Stay tuned for more updates, forumers....
Am looking forward to them...
Mark in Oregon
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Sweet!
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TCS Z2 decoder installed.
I should mention that I removed the rear thrust washer from the worm shaft. It made noise, as Victor predicted.
The extra wires are for the headlight LED, which will point upward at a very short optic cable, which is threaded thru the headlight casting.
(https://lh5.googleusercontent.com/-kC8yMeZYYZ0/VUKU4iB84HI/AAAAAAAABAU/P8cp6WNnZKQ/s2282-Ut/image.jpg)
An improved side view. The boiler has been straightened, but it's a little low in the front.
(https://lh4.googleusercontent.com/-hVkxhnPovmc/VUKU4q531aI/AAAAAAAABAQ/iiWuS0YpdiQ/s2048-Ut/image.jpg)
The motor still sticks out a little from the rear of the cab, but not nearly as much.
(https://lh6.googleusercontent.com/-MmTSzJV1exA/VUKU4i82UKI/AAAAAAAABAI/f1n3UrMSIIQ/s2048-Ut/image.jpg)
In case you were thinking that this project is almost done, let me tell you what else went wrong.
I applied track power to the loco's frame and got the drivers to turn. A little stiff, but not too bad. Noticed some wobble in the #2 driver set.
Then I placed the loco onto the track. This is where the problems started.
The wobble that I noticed prevented all of drivers from contacting the track at the same time. Result is that there is almost no electrical contact coming from any of the loco's drivers.
Closer inspection of the #2 driver revealed that the plastic face is cracked, as if a too-large pin was inserted into the face. This, in spite of the fact that this driver is not attached to the main rod. I know, this doesn't make sense. This unit was apparent repaired before I got it, in spite of the fact that I bought it new, from a very reputable dealer. The screw that held the two halves of the frame probably went missing at the same time.
So I plan to replace the defective driver, along with the rods and valve gear if I can get them. Oh yeah, the pins that attach the rods to the #3 drivers are not exactly straight, either. This can't be helping.
The saga continues...
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Don't know if it matters with the other problems, but you have one rod installed wrong.
(https://lh3.googleusercontent.com/-JLU-uZFs2TM/VUKjmWDKgzI/AAAAAAAANwA/sCF58C0aXHY/s800/image.jpg)
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That kind of jumps out at ya, doesn't it? :D
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Don't know if it matters with the other problems, but you have one rod installed wrong.
Oops. Looks like the rod on the other side is wrong, too. Thanks, Chris.
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Received a set of drivers, cylinders, and valve gear from Bachmann. The drivers, however, are quartered 180 degrees opposite from the drivers currently on the loco, so they are not interchangeable. A call to the Bachmann parts department revealed that they were unaware of the new quartering scheme.
So this left me with 3 options that I could think of:
A. Replace all the drivers, meaning that I would throw away 3 perfectly good ones.
B. Try to re-quarter the #2 driver. (The probability of me being successful with this is less than 1%).
C. Use the parts on the loco and try to make them work. (Using all of the new parts as spares).
I chose C.
I scraped a tiny amount from the top of the #2 bearing pocket in the frame; this prevented the #2 driver from "jacking up" the left side of the loco. This seemed to improve electrical contact. I also experimented with the torque on the fasteners that hold the motor and the lower plate to the frame.
Performance is not perfect, but the loco runs very quietly, and reasonably smoothly at low speed. Should run a little better after break-in.
This episode has left me more than a little disenchanted with Bachmann steamers. The first couple of people that I talked to in the Bachmann parts department did not know what the term "quartering" meant. I have a couple of other Bachmanns, and they don't run that well, either. Which is too bad, because I have another nice Jason Smith boiler shell that I was thinking of using on the 2-10-2 chassis to make a PRR N2 steamer. Oh, well. We do the best we can.
Next steps: Add weight to the inside of the boiler, add details to the exterior of the boiler. More pictures, when that part is done.
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Try not to be too disenchanted with Bachmann.
I consider them very valuable even though I have a love/hate opinion of them.
Generally, my experiences calling their parts department are equal to yours (meaning they are
fairly hapless and don't really understand the models they are servicing).
I also have never started with a Bachmann engine for a kitbash or scratchbuild project, because, well,
if I am going to modify and bash, I am going to have to make changes anyway, and there are better-built
engine chassis out there.
So why do I consider them valuable? Because for all their faults, they keep trying to make new American prototype steam locos and nobody else is really doing that. Kato and Athearn have done a scant few, but nothing
on the scale of what Bachmann is trying to do.
I also consider them to be a valuable source of parts.
So I don't want them to quit trying. If they ever get it right, I will buy.
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What a cool project! Looks like I will need to revamp my shapeways H10! Can you compile a final parts list? Aside from the driver issues, do you think this is something that could improve all Bachmann 2-8-0s?
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piperguy,
I would like to have one of what you have done thus far.
I have a different motor in mind but the idea is otherwise much the same.
I have almost purchased your tender and cab... many times.
I don't mind if you improve it, buuuut I need to have something to see the fitting.
as an aside on the subject of modeling, you may want to stretch your shell a little.
this is to allow the slightly for the larger flanges of n-scale.
my off hand guess is the shell from steamchest to cab needs about 1.5 mm to 2 mm more.
.
victor
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Try not to be too disenchanted with Bachmann.
I consider them very valuable even though I have a love/hate opinion of them.
I think that we are on the same page, Max, although I may be a little more pessimistic than you. It's because I have seen first hand what questionable designs and poor customer support can do to a company. I spent all of my career in the U.S. automotive business.
On the plus side, Bachmann does have some very nice looking steamers.
Can you compile a final parts list?
I can, if anyone is really interested. The problem is locating the Mashima motor. I found a small number at a dealer in the Czech Republic*. But, as far as I know, they have not been made for several years. No, if I were going to do this again, I would start here:
(https://lh3.googleusercontent.com/-YDisIcz-hCU/VU5aGNJZ5_I/AAAAAAAABDY/ncXan47lbHc/s2048-Ut/IMG_0225.JPG)
It's a Kato model 9600. Does anyone have any experience with this one? The motor is mounted more forward, so it probably not have to be relocated/replaced. DCC friendly. And it does have a flywheel.
Looks like I will need to revamp my shapeways H10!
Piperguy, have you printed the tender in FXD material? It may improve the detail on the sides.
*Edit: originally wrote Czechoslovakia. No offense to our Czech friends.
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Jim, the 9600 is a much smaller loco. It is quite nice and a solid mechanism for some other project. I have it for a 0-8-0 swicher.
Otto K
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We interrupt this thread for a Public Service Announcement.
Attention all Bachmann-ites
If you own a 2-8-0, I want you to pick up the loco, turn it over, and grab each wheel in turn and wiggle it side-to-side and forward-backward. Each axle should be "loose", i.e. no friction at all. If your engine does this, then you are done. Skip to the next post.
(https://lh3.googleusercontent.com/-cSzjxhWQEzs/VU5W0T2dJOI/AAAAAAAABCk/etW34ARfta4/s2048-Ut/image.jpg)
If there is any resistance in any of the axles, then I want you to carefully remove the bottom cover, as shown. For those of you who have not done this before, be very careful that you do not pull any of the drivers out of the frame, or you will spend a long time putting everything back the way it was.
(https://lh6.googleusercontent.com/-zsrys5x7-iY/VU5W0RFdo3I/AAAAAAAABCc/uZ4DTDfV-6w/s2048-Ut/image.jpg)
Notice that there are 2 ridges that run along the sides of the top of the cover. Thie ridges are about 0.015" high. What happens is that the ridges cause the cover plate to bend as the screws are tightened. As the cover plate bends, it comes in contact with the gears. You can see that this will cause all manner of problems.
So what you need to do is find some 0.015" thick plastic (like from packaging material) and fabricate 3 spacers as shown. If you size the i.d. of the spacers correctly, they will serve to retain the screws. This will make reinstallation of the cover a bit easier.
My cover also had some flash around the openings for the gears. The flash has to go.
We now return you to normal forum operations...
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Jim, the 9600 is a much smaller loco. It is quite nice and a solid mechanism for some other project. I have it for a 0-8-0 swicher.
Otto K
Otto, thanks for the reply. Would it be possible for you to measure the diameter of the drivers, and the wheelbase (distance between the c/l of the #1 driver to the c/l of the #4 driver)? Thanks.
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Jim, I'm in Denver visiting the kids, will do when I get back. Otto
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We interrupt this thread for a Public Service Announcement.
Attention all Bachmann-ites
If you own a 2-8-0, I want you to pick up the loco, turn it over, and grab each wheel in turn and wiggle it side-to-side and forward-backward. Each axle should be "loose", i.e. no friction at all. If your engine does this, then you are done. Skip to the next post.
(https://lh3.googleusercontent.com/-cSzjxhWQEzs/VU5W0T2dJOI/AAAAAAAABCk/etW34ARfta4/s2048-Ut/image.jpg)
If there is any resistance in any of the axles, then I want you to carefully remove the bottom cover, as shown. For those of you who have not done this before, be very careful that you do not pull any of the drivers out of the frame, or you will spend a long time putting everything back the way it was.
(https://lh6.googleusercontent.com/-zsrys5x7-iY/VU5W0RFdo3I/AAAAAAAABCc/uZ4DTDfV-6w/s2048-Ut/image.jpg)
Notice that there are 2 ridges that run along the sides of the top of the cover. Thie ridges are about 0.015" high. What happens is that the ridges cause the cover plate to bend as the screws are tightened. As the cover plate bends, it comes in contact with the gears. You can see that this will cause all manner of problems.
So what you need to do is find some 0.015" thick plastic (like from packaging material) and fabricate 3 spacers as shown. If you size the i.d. of the spacers correctly, they will serve to retain the screws. This will make reinstallation of the cover a bit easier.
My cover also had some flash around the openings for the gears. The flash has to go.
We now return you to normal forum operations...
Simpler solution to all this.....Don't crank the screws down tight. This has been a common fix for these loco's for years.
Also, I believe the motor you seek is an OEM Atlas part... Replacement motor for an MP15.
I used them a few years back to re-motor a couple old Arnold GG-1's for a friend. They worked great.
(http://www.trainboard.com/railimages/data/1888/GG-1_Remotor_Quarter.jpg)
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Do you mean the Mashima 1015 motor you used in this project?
You can get it from a lot of places. You just have to dig through all the overseas sources.
Here are some I know of that carry it:
One is the Czechoslovakia dealer you mentioned: (I think you mean this one: http://www.pojezdy.eu/eshop/6-mashima-motors (http://www.pojezdy.eu/eshop/6-mashima-motors))
I have exchanged some messages with him, but never bought any motors because the shipping was just too expensive.
They are also available from micro-loco-motion (Eldon Shirey) http://www.micro-loco-motion.com/ (http://www.micro-loco-motion.com/) (his website has not been
updated in years. Just email him). I've bought lots of motors from Eldon over the years, and he is still my go-to guy
for Faulhaber, Maxon or Mashima.
Hollywood Foundry in Australia: http://www.hollywoodfoundry.com/ (http://www.hollywoodfoundry.com/) I've bought from them. If you buy a few motors,
their prices are good enough that the shipping isn't oppressive.
There is also a seller from Germany who regularly sells lots of 3 or 10 of those Mashima 1015's on eBay.
Gizmoszone.com from Hong Kong also has them.
///////////////
One final edit:
Isn't that Atlas MP15 motor a 3-pole motor? If so, it is not the same as the Mashima. It may fit and work well, but
just so people are clear: they may be the same physical size, but they are not the same motor.
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Simpler solution to all this.....Don't crank the screws down tight. This has been a common fix for these loco's for years.
Sorry, tried that solution, SkipGear. The engineer in me will not allow loose parts on the engines. They usually fall off, invariably in the middle of a tunnel.
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Do you mean the Mashima 1015 motor you used in this project?
You can get it from a lot of places. You just have to dig through all the overseas sources.
Here are some I know of that carry it:
One is the Czechoslovakia dealer you mentioned: (I think you mean this one: http://www.pojezdy.eu/eshop/6-mashima-motors (http://www.pojezdy.eu/eshop/6-mashima-motors))
I have exchanged some messages with him, but never bought any motors because the shipping was just too expensive.
Max, that is the motor I used. Shipping from the Czech Repubic was not that bad. Six dollars for 2 motors via FedEx.
Did not realize that these are still available from so many sources.
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Otto, thanks for the reply. Would it be possible for you to measure the diameter of the drivers, and the wheelbase (distance between the c/l of the #1 driver to the c/l of the #4 driver)? Thanks.
Well Jim, I'm back home, and it seems I remembered it wrong. :facepalm:
I do own the 9600, but it's not Kato but MicroAce. It IS a much smaller loco than the Bachmann 2-8-0, I remembered that correctly. For what it's worth, the MicroAce has a fixed wheelbase of 16' (1.2") and 52.3" (.327") diameter wheels, perfect for a 53" drivered switch engine. Don't know about the Kato version, but suspect it is very close.
Here's a comparison photo of the MicroAce and Bachmann consolidations...
Kind regards, Otto K.
[attachimg=1]
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For what it's worth, the MicroAce has a fixed wheelbase of 16' (1.2") and 52.3" (.327") diameter wheels.
Otto, thanks very much for taking the time to get the information. The MicroAce is very close, but not quite close enough for me to make it work.
Regards.
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So the moment of truth arrived for the project engine. Here are the test measurements:
DCC Speed Step 1/28 - speed is less than 1 mph. Motion is constant, but jerky. A flywheel would smooth out the jerkiness, but, well, we don't have room for one.
Speed Step 2/28 - speed is 3 mph. Engine runs much more smoothly. Performance is ok, by my standards.
Speed Step 7/28 - speed is 15 mph. Either without, or while pulling 14 boxcars. ok.
Speed Step 14/28 - speed is 25 mph with 14 cars, 32 mph without. ok.
Speed Step 20/28 - speed is 25 mph with 14 cars, 40 mph without. A little slow, but still ok for this class of locomotive. I'm thinking that the speed may increase with more break-in miles.
Higher speed steps do not increase the engine speed, but they do make the electric motor really hot. Too hot to touch.
The other annoying thing is that the engine rocks back and forth after pulling 14 cars for about 15 minutes or so. This is apparently caused by the traction tires moving sideways in their grooves, and changing their shape ever so slightly. Those drivers have to go. Going to use Kato Mikado tires, too.
I wish I had a way to measure the motor current and voltage, but, with DCC, I don't.
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run the loco on DC and measure the volts and amps.
the current will be the important part. the voltage will be higher.
With most decoders you will get a good approximate by subtracting 4 volts.
victor
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Ack! Heat! No!
I agree with Victor...
Bypass the decoder, run this on DC, and measure that current before you do anything else!
If that motor got that hot, it may already be too late.
This one really concerns me:
"Speed Step 20/28 - speed is 25 mph with 14 cars, 40 mph without." That's a huge swing with only 14 cars.
Coupled with the high motor heat, either the motor is plain overloaded or there are frictional
forces in the geartrain that get really high when there are some cars on the train. That little Mashima is
pretty powerful for its size, so I think it should be able to handle this without getting hot. Can you
look at it running with the shell off? Maybe with cars on it, the worm is getting pushed hard against
one end or the other, or the ball/cup is using up all its slack and pushing on the motor bearings.
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My guess by looking at the earlier pictures is that the worm under load is driving itself into the bushings and causing the extra drag. There needs to be a brass or teflon thrust washer on either end of the worm shaft between the worm and the bushing. That may help some.
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My guess by looking at the earlier pictures is that the worm under load is driving itself into the bushings and causing the extra drag. There needs to be a brass or teflon thrust washer on either end of the worm shaft between the worm and the bushing. That may help some.
This. I was thinking the same. Teflon or Mylar would be best.
-
small ball bearing?
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small ball bearing?
Axial thrust on the worm graer and its shaft can only be prevented if they are opposed tapered roller bearings shouldered against the worm and trapped in the frame. :D LOL. Does anyone make them that small? :D
Has he determined if thrust friction is actually the culprit?
-
the cause of the heat is power into the motor...
I have a set of indicators.
If the motor heats quickly, the motor shaft is bound
if the loco seem bound or tight and the motor take a while to warm
it is a driver or idler gear past the worm.
I have not been able to tell if the motor is a 6 volt type or if the mechanism is bound up.
lemosteam,
one of the things I love about well trained engineers is that they often have the right answer.
you are correct.
now can we have a conversation about 'close enough?'
if you want you can read the specs on the various 1 and 1.5 mm ID bearings
I am pretty sure that an n-scale motor and worm are not even close to
the weight limits for axial thrust.
it is easier to install a thrust bearing into an n-scale loco than a ball bearing cassette.
... you may want to take my word for this....
don't bother with the thrust bearings.
I've built ball bearings to ride on worm and shaft.
they work. like the bicycle bearings they resemble,
they perform better with careful adjustment.
at 50 cents a bearing the bearings are effective and easy to adjust.
and if you wear them out.... replacement is a few minutes and a dollar in parts.
I'll bet they outlast a kato FEF motor....
victor
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As planned, I replaced the drivers, added Kato tires, and replaced half of the valve gear. The other half of the valve gear that I purchased had a crosshead lever that was frozen, so I did not use those parts. The Bachmann parts diagram also called for a washer between the connecting rod and the side rod, but these were missing, too, so I fabricated and installed new washers.
In this process, I also noticed that the LH side rod was bent about 10 degrees, in the side view, so I straightened it. This is a photo after straightening.
(https://lh3.googleusercontent.com/-WPNHdwoEPnA/VVPJt-o4bcI/AAAAAAAABFE/OC5SAqeco-c/w1060-h190-p/image.jpg)
You can see the nick in the rod. Something had apparently hit it with some force, and caused the side rod to bend. Can't imagine what that was. It also looks like someone had drilled out the holes for the side rod pins (both sides). I would have ordered new side rods, but they are not available from the Bachmann parts store.
Put it all back together and she ran slightly faster and smoother, as expected. Will put a few miles on her tomorrow, and take some speed and maybe volt & current measurements.
The motor only gets slightly warm at half speed (14/28), but it does get hot at 3/4 speed. But the motor ran hot on the bench at 3/4 speed without any load (not installed in the chassis). Victor could be right; this could be a 6 volt motor. Even though there is a sticker on it that says it is 12 volts.
I wish you guys would make up my mind regarding the thrust bearing. The worm does load the motor bearings, as SkipGear deduced, so I originally had a Delrin thrust washer to prevent this. It's shown in one of the photos above. But Victor predicted that it would make noise (it did) and I think he said that it was unnecessary. So I removed it. To reinstall a thrust washer at this point may not be worth it. Since I think the top speed of the prototype was about 50mph, I'm ok with using the decoder to limit the max voltage to 6v.
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Jim, very interesting thread, thank you. It is a pleasure to follow.
As you indicated, these engines didn't run over 50 mph (and in most circumstances, probably not much over 30 I'd bet) so I wouldn't worry about having to limit the top speed for that reason. The real test will come under load, with say your 14 cars in tow; how will the limit affect speed and pulling ability... I have some tall-geared, underpowered brass that performs well, but fizzles under load.
Looking forward to your updates,
Otto K.
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the side rod looks right to me.
the main crank hole is bigger than the first and fourth driver crank holes.
If the sticker says it is 12 volts then we will assume it is.
getting hot at 12 volts is not out of the ordinary for small motors
that are rated at 12 volts. (If you think an Atlas diesel motor is a big motor anyway...)
the heat will tell you the current limits you want to stay under in any case
I'd pull 15 cars and see if heat is a problem.
victor
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A couple of you suggested in previous posts that I measure the current draw of the motor, to get a handle on the engine speed and motor heat issues. The results were interesting, to say the least.
First I took a spare motor, identical to the one in the loco. Powered it with DC on the bench, no load, as a baseline:
MOTOR ONLY, ON BENCH, NO LOAD
V, dc mA
1.3 20
3.7 34
6.4 37
8.4 39
10.5 40
12.6 41
15.5 42
18.0 44
The current draw is a little less than the spec. So far so good.
Next, I powered the loco on the bench with dc, thru the decoder, with no load on the motor except for the drivetrain:
LOCO, ON BENCH
V, dc mA
4.5 82
5.0 90
6.0 100
7.0 105
8.5 114
17.0 150
These numbers still look ok to me, but then I don't have much experience taking these measurements. What do the experts think?
Lastly, I put the loco on the track and powered the decoder with dc. Immediately, I noticed a couple of things. The top speed increased, and the motor ran much cooler. It's as if running the motor on dc reduced some of the friction in the drivetrain. I measured the loco by itself, and with it pulling 20 cars on level track.
LOCO ON TRACK, WITH DECODER
LOCO ONLY LOCO + 20 CARS
Volt mA mph mA mph
5 86 94
6 104 106
7 113 120
8 119 132
9 124 139
10 130 142
11 132 145
12 137 151
13 140 46.8 151 36.4
The motor got warm after pulling the 20 cars for about 15 minutes, but it was still ok to the touch.
At this point, I also tried to put to rest the thrust washer versus no thrust washer issue. This is for the washer on the rear of the worm gear, also discussed in previous posts. I ran the engine forward and reverse, at several speeds. The current draw, speed, and noise level were almost identical for the forward and reverse directions. So, no need for the extra thrust washer.
I welcome all of your comments. Sorry if the columns of numbers are not straight. I know that this will bother the engineers out there. It bothers me.
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what a magnificent post.
in what may seem like I am ignoring a lot of the data you collected
here is my guesses on your result.
I found a datasheet that says the max current
at 70 ma at 12 volts
to me that means you want to stay under (70ma*12v-->840mW)
from what I see in your data the voltage and current is pretty linear
I suspect the decoder is involved. I am thinking the decoder is using about 100mw here...
My recommendation is that you stay under 1200mW
the 20 cars 8 volts and under140mw is likely to be your real limit.
victor
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The Mashima 1015 70mA limit is for no-load on a bench.
Several years ago (5? more? cannot remember), it was actually possible to email
Mashima and speak to the company president about the motor specs. Their website used to have the email address and they
used to answer it. They do not any more.
I was wondering what the real load limit was for the 1015 (coincidentally), so I asked them.
I got back a reply from Mr. Katsumi Mashima (he is THE GUY). It was a hoot. He had worked out current and torque curves
on the motor, drawn it all out hand-written on paper, and someone there (maybe him) scanned it and emailed it to me.
I am going to dig around to see if I can find it.
All I can remember is that the actual operational load limit for that motor was much higher than 70 mA. I want to say it was about
200 mA, but I cannot really remember, so I will try to find those notes. I really hope I didn't lose them.
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Hi Max,
no load bench 70ma is max....
not what the spec I read said...
....oddly enough
http://www.gizmoszone.com/shopping/html/pages/mgh1015datasheet.pdf
some one's datasheet...
happy reading.
it says 3400 rpm and 70ma and then lists off to one side no load....
I think there may be a gearbox involved...
another...
http://www.hollywoodfoundry.com/mashima%201015.jpg
it lists 350mW as the max power output....
so there is some inconsistencies in the ratings. 70 by 12 volts is 840mW
I tend to go by how fast it gets hot...
and to drag in a couple of important items to note
overall size is a leading factor in how much heat can be dissipated.
the Kato Chibi motor is similar size and gets hot at over 7 volts and over 150 ma
which is the main reason I stated the limits I thought reasonable...
the 150ma is ok at 5 volts BTW
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Max,
I want very much for you to share the Mr. Mashima's datasheet
because I would believe it.
the other datasheets are ... inconsistant.
my conclusions are not standing on data that is good enough.
they are based on facts I do not trust.
victor
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May I write a little aside here? OK, I will.
Back in the late seventies when I worked for Telex and we made 8-track raw decks for Ford, we used Katsumi self-governing motors for the quadraphonic units. These were made by the same company and I imagine they just used different parts of Mr. Mashima's name for different product lines.
He (I am assuming it's the same Katsumi Mashima) and others from the company used to come to Rochester when there were any issues with their motors and it was a blast.
I also want to add that 200mA is pretty common for any normal sized N scale motor as a nominal in-use current draw. Smaller ones, of course, may be expected to tolerate less.
Doug
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Doug,
WONDERFUL story about meeting Mr. Mashima!
Victor,
So far I have been unsuccessful at finding that hand-written sheet. I am going to keep digging around. It was so much more
than a data sheet. I showed not only various power, current, and torque ratings, but it showed how he calculated them,
complete with little hand-drawn graphs. It was like a brief lecture series in how Mashima designs and rates their motors.
Boy oh boy... I hope I can find it. I hadn't thought about it in years, until this came up.
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That's really neat, Max. I can tell by your description that the sheet reveals the typical intensity of the Japanese in their endeavors and we at Telex experienced the same thing. Those guys got right down to it and didn't let up until a problem was solved.
Then we would go out and have fun at night. :D
Doug
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I spent a little time hunting in my basement/shop/laboratory this evening.
I found one of the motors that looks like the one in nscaleSPF2's photos
I turned the power supply up and ran the motor to where my meters
said 12 volts and the current draw there was 50 to 60 ma.
without touching the throttle,
I stalled the motor.
the meters read 180 ma and 9.5volts.
the motor got noticeably warmer...
my conclusion is that 200 ma is the stall current at 12 volts.
max possible power from this motor is
200ma times 12 volts --> 2400mW
my rule of thumb for motors is that half of stall power is a reasonable limit.
victor
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So the consensus seems to be that we are good to proceed with the build.
I am still trying to make a little more sense out of the data that I recorded a couple of days ago:
I put the loco on the track and powered the decoder with dc. I measured the loco by itself, and with it pulling 20 cars on level track.
LOCO ON TRACK, WITH DECODER
LOCO ONLY LOCO + 20 CARS
Volt mA mph mA mph
5 86 94
6 104 106
7 113 120
8 119 132
9 124 139
10 130 142
11 132 145
12 137 151
13 140 46.8 151 36.4
It occurred to me that the current measured includes the current that flows thru the decoder. I don't know how much that is. Neither did the technician I asked at TCS. No one had ever asked them that question before. I suppose that I could measure how much current the decoder draws, by disconnecting the motor and applying dc to the decoder. Are there any decoder experts out there who would care to offer an opinion, or better, data?
Next step is to re-gage the new drivers that I just installed. Should have measured them before they were installed. Silly me. Two steps forward, one step back. Man, this build seems to be taking forever.
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It occurred to me that the current measured includes the current that flows thru the decoder. I don't know how much that is. Neither did the technician I asked at TCS. No one had ever asked them that question before. I suppose that I could measure how much current the decoder draws, by disconnecting the motor and applying dc to the decoder. Are there any decoder experts out there who would care to offer an opinion, or better, data?
The additional (10-15mA) current while DCC decoder is in the circuit seems reasonable for what a DCC decoder circuitry would draw (with the function outputs off). I'm surprised that the manufacturer's support personnel would not know this type of info. :|
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Thanks for the info, Pete. I won't need to desolder the motor lead, at this point.
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The additional (10-15mA) current while DCC decoder is in the circuit seems reasonable for what a DCC decoder circuitry would draw (with the function outputs off). I'm surprised that the manufacturer's support personnel would not know this type of info. :|
Hi nscaleSPF2,
I am quoting peteski because I both think the miliamps for the decoder is in the ballpark
and it needs a little more information.
If you had asked me how much power the decoder uses I'd have said about 100mW.
or about 20ma and 5 volts.
this is chainsaw carpentry, it leaves some to be desired....
If you run your loco with the decoder the first 4 to 5 volts and 10 to 20 ma will 'light' the decoder
then the decoder will attempt to spin the motor.
you can subtract the power in mW.
for what you are doing it may be the better way to keep an eye on the motor.
use mili-Watts.
victor
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Hi Victor,
At 3V, current drawn by decoder + motor = 60ma. Speed = 0.
At 4V, current drawn by decoder + motor = 70ma. Speed = 0.
Had difficulty getting consistent readings at less than 3V.
So much for the chainsaw science.
I have to get back to installing some air lines.
Regards
-
the numbers are good.
It is a little hard to guess how hard the decoder is trying to move the motor.
the lower end at 3 volts is a good set to use.
we are guessing here because we do not want to desolder to put test meters in the circuit.
at 3 volts the decoder begins to operate AND tries to spin the motor.
that is 60 miliamps times 3 volts --> 180 mW
it is possible that the decoder is using all of that power and is sending none to the motor.
and on the other extreme: the motor's static resistance is 50 ohms
at 3 volts divided by 50 ohms --> 60 miliamps
This does imply the decoder is using no power.
Off we go. on to another possibility.
from the free motor part earlier...
you wrote this
MOTOR ONLY, ON BENCH, NO LOAD
V, dc mA
...
3.7 34
...
my thinking is that at 4 ish volts
you know the motor can absorb about 34 miliamps.
this is within reason.
34ma * 3.7v --> 125 mW
180 minus 125 is 55...
that leaves 55 mW to run the decoder.
so we have a number to subtract from the overall power.
I suspect that figure is on the low side.
in that we do not know how much of the 180mw the decoder is sending to the motor.
from my tinkering with PIC processors, they can run at 3 volts
and I do not remember specific power consumption figures.
the way one uses pheripherials has a lot of affect on the number.
so, your choice, subtract 50 to 180 mW for power to the decoder.
I'd use 100mw 'cause it is easy to calculate.
edited to change an ma to a mW.
context makes it pretty clear and I decided to change it anyway
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OK, Victor. I think I understand what you are saying. The numbers seem to say that we are good to go with this combination of motor/decoder/chassis.
But the real test is keeping the the maximum motor temperature below a certain threshold, is it not? The armature windings need to say below the temperature that will melt the insulation, no?
Any idea what this temperature is? And how to measure it? Maybe an infrared thermometer? There are several of these for less than $20, but I don't know if they would work.
Pardon me if I seem a little anal here, but I'm just curious.
-
Measuring the motor armature with an IR non-contact thermometer: you are taking modeling to the next level here! :)
The non-contact thermometers work quite well but they sense the average temperature in their cone of measurement - you will have to get very close to the armature to accurately measure its temperature.
-
!!!
things I did not expect....
Hi nscaleSPF2,
the commercial motor I have met _LOOK_ like they are insulated
with high temp coatings. it is the color of gold kapton tape.
that stuff is supposed to hold up to 450 degrees
(assuming my memory from slotcar wrapping and wire specifications is accurate)
I think the nylon insulation is good to 250. I know no easy way to tell the difference.
I would state if you are driving the motor to 250 degrees you are overrunning it.
If you can't keep a finger on it, you are too hot.
at this point I can only share what I do.
I run the loco by itself at 8 volts for a minute at what ever speed it does.
and I set a finger on it. If it heats up enough to make me uncomfortable...
something has to change. motor, gears, bearing alignments, anything.
If the motor is only warm then I assume all is good and run it
and check it every ten minutes for a half hour.
it should level off to a friendly warm.
what you want to avoid is what ever heats the motor quickly.
heavy loads and high voltage will get heat fast.
use your finger tip as your temperature sensor.
my opinion about your motor/chassis/decoder combo...
you are at about the limit of the motor's power output.
12 volts and 20 cars is likely to over heat the motor.
the 8 volts 132ma and 20 cars is about all the numbers state you should do.
if you use the finger test, you will get a sense of the limits fairly easily.
If you run the loco for a few hours, it may loosen up and your current draw numbers will drop.
or install a bigger motor and run the chassis for a week straight to loosen it.
victor
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The color and texture of the material being measured also has a large effect on the measurements, especially with the cheaper units. I have one that I use for RC racing that can be calibrated to compensate for this.
-
the commercial motor I have met _LOOK_ like they are insulated
with high temp coatings. it is the color of gold kapton tape.
that stuff is supposed to hold up to 450 degrees
(assuming my memory from slotcar wrapping and wire specifications is accurate)
I think the nylon insulation is good to 250. I know no easy way to tell the difference.
In my experience all the enameled magnet wire I have dealt with (from back in the 70s winding transformers and chokes while attending telecommunication school in Poland to dealing with N scale motors and also using it for hooking up SMD LEDs) was not coated Kapton or Nylon. the insulation can easily withstand couple of hundred degrees Celsius (quite a bit more than 200 F). Good insight of what the "enamel" is made of is here (http://en.wikipedia.org/wiki/Magnet_wire#Insulation)
-
color of gold kapton tape....
and one of the possible coatings is polyamide
which is the magic ingredients in kapton tape...
and thanks for the wiki link.
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OK, Verne, it's time for another public service announcement, so brace yourself.
Do you remember, Verne, when I told you that the pilot wheels didn't look right? I didn't think so. So I took a picture:
(https://lh5.googleusercontent.com/-GDYEf6OxiWE/VWjYkN6rhPI/AAAAAAAABHU/3raQDsVlg2I/s2048-Ut/image.jpg)
What problem can this possibly cause, you say? Well, there is no problem when the engine is on a straight track. But don't you remember, Verne, when she was going thru the Waynesboro tunnel? The front outside driver was trying to climb the outside rail, while the inside pilot wheel was gently rubbing the cylinder and trying to lift the inside. Presto, derail. Every time.
Verne gives himself a dope slap.
Now take the part on the left back to the shop, Verne, and make it about .03in longer.
(https://lh4.googleusercontent.com/-gy7jQmC7K3Q/VWjYkOfIH5I/AAAAAAAABHU/-YEkJ_Jyv2k/s2048-Ut/image.jpg)
Verne returns, several days later, with this:
(https://lh3.googleusercontent.com/-a3veO5WMYNk/VWjYkMDJLfI/AAAAAAAABHU/ECiGaCJI-Xw/s2048-Ut/image.jpg)
Now, I can think of 3 or 4 simpler ways to do the same thing, but what can you do? Feel sorry for Verne, he's only an engineer. At least the end result looks a lot better:
(https://lh4.googleusercontent.com/-8qm-xLp_-fA/VWjYkOyxA3I/AAAAAAAABHU/0iZqQYp9ZhY/s2048-Ut/image.jpg)
Ok, Verne, now go grab a cold one while I try to get some temperature measurements.
-
I'm pretty sure I just moved the pilot back on mine, but it was long ago. Knowwhatimean?
-
I was able to obtain some temperature data, using a fairly inexpensive infrared thermometer.
(https://lh6.googleusercontent.com/-RrIhkRE8o5U/VWpTv-w1XVI/AAAAAAAABIY/vMfKquAT--A/s2048-Ut/image.jpg)
This device proved easy to use, and gave pretty consistent data. I held it 3 to 4 inches away from the motor, pulled the trigger, and scanned over the surface to get the highest temperature, which proved to be near the rear bearing. The temperatures recordered were on the outside, of course. We don't really know what the internal temperatures were. Here is the data, with the engine pulling 15 cars on level track at 3/4 throttle.
Time. Temp.
1min. 98degF
2. 109
3. 111
4. 114
6. 123
8. 122
10. 128
15. 133
At the end of 15 minutes, the motor was indeed very warm to the touch. This is also consistent with some Internet research; I found that you are not supposed to be able to hold your finger on a metal object that is hotter than 140degF.
So what does the data tell us? For one thing, I think that Victor said that a high temperature very soon after the engine starts to roll indicates that there is a binding in the drivetrain. That does not seem to be the case here, so I think that we are ok for binding issues, at least for now.
Also, even though we do not know the internal temperature of the motor, I'm thinking that it can't be that high, given that the external temperature only got up to 133 degrees. If I had run the engine longer, the temp would probably have gotten up to 140deg.
Anyone have any thoughts on this?
-
My thought is that the rise in temperature really started to level off there at the end, rising only 1 deg per minute.
So I'm not sure that it would ever reach 140. Maybe, but I sort of doubt it. I think you were reaching the peak there.
I agree with Victor's opinion... if the heat rises quickly on startup, it's probably not because it's pulling too many cars up a hill. The motor would have to be severely overloaded to cause such a quick rise and that would imply a bearing or other bind.
So I don't think you have that problem.
It's hard to know what the normal expected operating temperature of that motor is. It could be running at
the peak of its capacity, or it could just be built to run hot. But I've used Mashima 1015's in other engines, even a
Bachmann 2-6-6-2 remotor job, and I don't recall it getting uncomfortably warm like that, even with it
pulling 30-40 cars. The 2-6-6-2 is geared down pretty well, but then, so is the Spectrum 2-8-0.
So I am still wondering why all the heat.
-
Of course I am going to jump in!
COOL Gizmo!
the rear bearing being the warmest indicates the armature is the source of the heat.
the motor magnets are getting warm, just not as fast.
the other thing is you may want to try to hunt a speed/load where the temperature stabilizes.
lower the throttle or take off a few cars and run that same test.
my opinion is that 3/4 throttle and 15 cars requires too much power for the motor to supply.
it is close, in that 15 minutes and 140 degrees is not a dangerous combo.
if 14 minutes was 138 and minute 16 was still at 138 I say it has stabilized
and while hotter than I'd like, it is serviceable.
my other opinion is that the motor can survive at 180.... and your model if plastic will melt.
we have to find a way to get the current draw down a touch...
I have to think a bit.
victor
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Thanks for your responses, Max, Victor.
Max, was the 2-6-6-2 remotor powered by DC or DCC? Do you think that this would make a difference in the amount of heat that the motor generates?
The other cause for the heat may be that I damaged the motor when I Loctited the motor shaft to the forward bearing. I applied 12 volts to the motor while it was stalled, for probably less than 1 minute. If I did damage the motor this way, then I am just going to run it until it stops, then replace it.
Meanwhile, the engine is finished, except for paint:
(https://lh5.googleusercontent.com/-_u2iyxheS8Q/VWzMhDSb8iI/AAAAAAAABKg/lKt1V53ugAI/s2048-Ut/image.jpg)
(https://lh3.googleusercontent.com/-rJ1fyK7gLGQ/VWzMhCdt2oI/AAAAAAAABKM/smGXHItZSVg/s2048-Ut/image.jpg)
(https://lh5.googleusercontent.com/-H-8GrU_6hRg/VWzMhK4viVI/AAAAAAAABKk/aCy1Q2hKxQg/s2048-Ut/image.jpg)
A small part of the motor still hangs out of the back of the cab. Hopefully, once the tender is installed, this will be less noticeable.
(https://lh6.googleusercontent.com/-yznp1l-h8Ks/VWzMhLGELYI/AAAAAAAABKM/xNdXERX1nyA/s2048-Ut/image.jpg)
-
you are done with the easy part.
blowing paint onto all that hard work is the toughest part.
I have grown familiar with sagging paint.
it adds character!
ooof
luck in your painting and decaling.
victor
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Jim, that is very very nice, even magnified.
As to the motor, may I suggest a closely coupled tender and canvas curtains in the cab?
Nice work; Jason will be proud :D
Otto K.
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Thank you, Otto, for your kind words.
you are done with the easy part.
blowing paint onto all that hard work is the toughest part.
I have grown familiar with sagging paint.
it adds character!
ooof
luck in your painting and decaling.
victor
victor,
painting, like everything else in life, is very simple.
it takes a few basic principles and lots of practice.
make sure the surface is clean.
thin the paint.
apply a few very, very light passes (with an airbrush).
let dry and apply a few more passes.
repeat.
you can find any number of forum threads to describe the process.
bottom line is you have to find what works for you.
and practice.
could this be a use for the roundhouse queens that you have lying around?
respectfully,
Jim
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+1 on the curtain to hide the back of the motor.
I've used that trick a few times. It's like making lemonade out of lemons. It doesn't just hide
the motor. It makes the engine look better!
Loctite in the forward bearing... It's really hard to say if applying current and having a stalling motor
for a while could permanently damage it. Magnets can lose their magnetism if they are overheated.
And it could be that some Loctite is making the shaft turn in that bearing less freely than it should.
I do know from getting Loctite into places where it doesn't belong, like a bearing/axle surface, that it
is surprisingly hard to really get it all out of there.
I think your approach of just running it and being prepared to replace it if it ever fails is sound as long as you are prepared for that possibility.
The 2-6-6-2 I did was straight DC.
Oh, and by the way, this is long overdue, but your engine really does look very nice. I look forward to
seeing it painted and lettered. I really like the air reservoir. And that brass pipe with the knobby thing
on the end of it, on the left side, coming down from the dome, bent in an "L" shape -- is that a
"repurposed" Precision Scale brass detail part?
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Oh, and by the way, this is long overdue, but your engine really does look very nice. I look forward to
seeing it painted and lettered. I really like the air reservoir.
Thanks, Max, that means a lot, coming from you.
And that brass pipe with the knobby thing
on the end of it, on the left side, coming down from the dome, bent in an "L" shape -- is that a
"repurposed" Precision Scale brass detail part?
The brass pipe is a wire that was bent to replace a cast resin part that broke off during handling. This seems to be one of the few disadvantages of these castings. The knobby thing is part of a brass grommet that simulates a coupling to the remaining part of the casting.
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The engine is looking very nice Jim. And yes Otto, I am proud to have made a small contribution! :D
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The engine is looking very nice Jim. And yes Otto, I am proud to have made a small contribution! :D
Lol Jason, "small" in scale only!
Glad to see you back, if only lurking right now :D
Call me when you have time to chat.
Best, Otto K.
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Project update. Tender is complete, except for paint.
(https://lh6.googleusercontent.com/-YETNOixLkM8/VXyQ-GFMhzI/AAAAAAAABNU/gGa--cyWPyE/s2048-Ut/image.jpg)
Lots of very nice detail, that does not show up in the photos.
(https://lh5.googleusercontent.com/--08hwZ8QqhY/VXyQ-LWeO5I/AAAAAAAABNM/ye-MfsQsg1A/s2048-Ut/image.jpg)
Dimensionally, the tender is very close to the prototype. The trucks are also spaced to get the proper wheelbase.
Verne is back in the shop, working on the drawbar. Who knows what he'll come up with.
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Looking really nice Jim! Keep up the good work!
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This is how the draw bar turned out. It is about 0.20 inches shorter than the stock one, shown above in the photo.
(https://lh5.googleusercontent.com/-vZsN-WtQcnM/VYyO19VSA8I/AAAAAAAABPA/zSWUv-sonc0/s2048-Ut/image.jpg)
The draw bar is made from .032in ABS, glued together with Plastruct cement. I dribbled some cement into the 2 holes, to make a stronger bond. This should be more than strong enough.
Jumper wires were soldered to the ends of the phosphor bronze wires, like so.
(https://lh4.googleusercontent.com/-K_TXGQIR544/VYyO15RqqJI/AAAAAAAABPs/QRlNLG0nkrM/s2048-Ut/image.jpg)
I added a bit more lead to the tender; it's weight is now up to about 1.5oz. The extra weight plus the jumper wires has just about eliminated any issues with electrical continuity.
The boiler and tender shells should be out of the paint shop soon.
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As promised, here are some photos of the finished locomotive. Sorry it took so long.
(https://lh4.googleusercontent.com/-of-OFJCRqEA/VZf4AjMOiqI/AAAAAAAABTc/poK6XSNoscU/s2048-Ut/image.jpg)
(https://lh3.googleusercontent.com/-aTTfJH6v16Q/VZf4AqlwOkI/AAAAAAAABTc/HSIT8w5N1lA/s2048-Ut/image.jpg)
(https://lh4.googleusercontent.com/-34bWjr0oK3A/VZf4AmwSohI/AAAAAAAABTc/mQN7_kAVREg/s2048-Ut/image.jpg)
Where did the motor go? There it is, behind the curtains.
(https://lh3.googleusercontent.com/-fvZC3ddhnA8/VZf4AkpvcWI/AAAAAAAABTc/8fGGDYR6L_I/s2048-Ut/image.jpg)
(https://lh3.googleusercontent.com/-2_xTBRRRedk/VZf4AhrI5VI/AAAAAAAABTc/fSiNTWkmhVk/s2048-Ut/image.jpg)
(https://lh4.googleusercontent.com/-_3pQ6yu2nEg/VZf4ApDBZFI/AAAAAAAABTc/qKAiSWt9wa8/s2048-Ut/image.jpg)
If anyone is interested, I may try to figure out how to shoot and post a video.
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Jim, that turned out simply stunning.
The freestanding details are superb, even under great magnification...
You've got yourself a winner!
Otto
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Yes, that did turn out very nice!
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Very, very well done!
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It's a beauty, sir. I really like the color. The cab curtains did the trick on hiding the motor.
Nobody will every notice it now.
REALLY nice model there. Congratulations!
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Outstanding. I almost prefer the unpainted shots because it really highlights all the details.
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Excellent!
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Thanks for the kind words, all.
I sprayed the tender and boiler shells with Floquil weathered black, and hand painted the trucks and running gear with grimy black.
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I think it looks fabulous, in spite of the fact I prefer the older, pre-war (?) style...
Very nice indeed.
Mark in Oregon
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Some very short videos. The first is taken at 25 scale mph. Please excuse the jerkiness of the camera.
This one was taken at DCC step number 1 of 128; this is equivalent to a scale 0.25 mph. I think that the engine runs very smoothly, given that it has no flywheel.
Finally, one last one.
Enjoy.
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I am not supposed to watch the videos from work.
:-) I am surprised no one has commented.
I like it.
victor
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Awesome! That's how steam should run.
The Mashima is doing a fine job there!
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+1
Mark in Oregon
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super...really excellent work
and a very fine shell to work with
kudos to you both,
nscaleSPF2 and superturbine
sincerely--
Gary
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Excellent work Jim! The smooth very slow speed performance of your loco is exactly what I would have expected to see on Carl's Kato GS-4 with a coreless motor and a gearhead.
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Thanks for all of the positive comments! I do appreciate them.
This was a big project for me. I'm glad that it turned out well.
I began this thread to explain how to make a PRR H10 out of a Bachmann 2-8-0, for anyone who may want to go down the same path. For those people, here a few suggestions:
1. Make sure that you have a really good running chassis before you begin. This will avoid the repairs that I had to make.
2. Make sure that all of the drivers contact the track at the same time. When you take the bottom plate off, mark the bottoms of the axle bearing blocks. You want to get them back in the same orientation. I know, the holes for the axles should be in the exact center of the blocks, but they are not.
3. At some point, you will have to completely disassemble the chassis. Work slowly and carefully. Do not force anything. Take pictures for yourself, to help you remember how to put everything back together. With this chassis, it is almost impossible to get the drivers out of quarter, so don't worry about that.
4. The Mashima motor works very well. There probably are others that will also work. There are sources to purchase the Mashima, earlier in this thread. There may also be a better way to mount the motor, although the way I chose does work.
5. Talk nice to Jason Smith (superturbine) and he may make you very nice boiler and tender shells.
Good Luck