Revamp cheap $5 gear motor. Subtitle: Return of the A-Board motor thread

[mmagliaro]

Top speed is a tricky thing.   For me, an engine with a top speed of 35 is about perfect, but many people would consider that
way too slow.  In a passenger engine, I'd want a top of about 60. 

I have a regeared Walthers 0-8-0 switcher that tops out around 15, and that's wonderful for switching.

So it's up to you and what you are shooting for.  I just wanted to point out what a 10:1 ratio is probably going to mean.

Love the thread.  Keep at it!

[randgust]

I guess I've evolved to a completely different philosophy.

I get the Gizmoszone 3v motor and gearheads with the plastic gearhead; 5.14:1 reduction, which is just sweet.   Perfect.   

I'm tearing out the 3v motor and putting in a motor from a Kato 12v 11-105.   Cases and drilling are identical.  This is also the same motor that is used in the Bachmann GE 44-tonner and GE 70-tonner, FWIW.  Same dimensions, markings, drilled the same - Bachmann is double-shafted.

I get a very tiny single-ended, low-speed, high-torque solution that when it fails (note I said "when") it's easy to replace.   I keep spares on hand as the the power plant has become somewhat of a standard in critter and small steam applications.  Also pretty darn quiet.

One thing I've noticed is that you can full-slip the end result and motor RPM doesn't drop.   This appears to be pretty easy on the motor and current readings I've seen.   I've done some 'direct-drive' experiments and those haven't necessarily gone well at all with these little motors.

It's not $5.   By the time I'm done I've got $35 into the motor if I throw out a Kato 11-105 (which I don't) and the 3v (which I don't).    I've decided these run so well that for me, it's expendable, particularly compared to a Faulhaber drive, which just is too big anyway for my applications.

You can, and could, put a dropping resistor in there and just run the 3v giszmoszone gearhead; that's my choice not to because under load I could definitely see the resistors getting hot and also the RPM variation was noticeable.

[timwatson]

Thanks Randy for chiming in here. Ghosts of the a-board motor thread arise!!! 
I guess the point of all this is I'm not shooting to find another mid priced solution. I want a cheap solution.

Here is what we have thus far:

------------- | High end | ---------------------- | Mid | ----------------------------- | Low | -----------------
Maxon, Faulhaber, Escap, ......... Mashima, Kato, Bachmann, ......... then we have down here where not much is available or viable.

This low end spot is the spot I want to work in. No more than $15 total is my goal. I think in this day and age we should be able to get a good motor with torque for less than that. Size is at play here too. 8mm x 10mm x 15m is a great size. I think I can get it there, I just need some more experimenting.

I'll have some time to play this weekend. I appreciate the debates and additional comments. When the search engines pick up good cheap n scale remotor I want people to have the options you all present here.

I will also take some video of the little roco switcher in action. You guys/gals can decide for yourselves what the speed is like.

[randgust]

OK, just for the record.    Went and checked.

The ones I like with the 2700RPM and the 5.14:1 list for $9.17  http://www.gizmoszone.com/shopping/html/pages/810datasheet.pdf

The Kato 11-105's from Plaza Japan:  $19.80 + shipping.

So it depends what you're going to do with the leftovers on how you allocate cost.  I put tinier gearheads on the 11-105's which is how I have leftover Kato 12v motors to spare; so for me I'm hitting your price threshhold.    For my Climax builds I've been doing more and more with 3v gearheads in them from robotshop.ca, but those are a very high RPM high reduction combination ideal for geared steam but not much else.    If you want to move something at 9mph for under $15 you can certainly make this work with a dropping resistor:  http://www.robotshop.com/en/solarbotics-gm15-gear-motor.html

The big deal with most of these gearmotors is that you have a single, unsupported, shaft to either mount a worm or a universal on.   If you can't put a shaft or a bearing support in front of the worm, you're torquing on that (usually plastic) gearhead shaft, and you really don't want to do that.  All of mine simply have a universal on the front end driving a shaft to another universal, NONE of mine are done with directly mounting a worm on the shaft.  That's as much of a consideration here as anything, because most of them simply aren't designed to handle the stress load on the shaft; only a rotational load.

I've lost track of how many of those I've done now.  I've got three myself.   Lots of video out there with them, search YouTube for 'randgust', same with the Kato+Gizmoszone.

[peteski]

IMO, ther $5 target price for a geared motor of any brand it totally unrealistic.  It is after all year 2014. Look at the price of your groceries, gasoline, or anything else around you.  The penny-candy is now a dollar!    Also look at the price of N scale locomotives. the brand-new $20 steam locos from Bachmann are now $50!

While I find this thread very informative and useful (since it shows gearbox modifications), I totally discount the $5 limitation.

[randgust]

One of my great (failed) experiments was getting a 'bag' of 9V Motorola pager motors, really tiny, for like $10 from Ebay.

Since I'd had such issues with the dropping resistor and observed great differences between 3v v. 12v under load (particularly without a gearhead) thought it might solve most of the problem with at least a 9v.    Put one on a Tomytec truck, direct drive to a worm on the offset truck tower, to power my 25-tonner concept.

I got it to run, and run well as a mechanism.  But NO torque, not even a little bit.   You could stall it out with its own weight, and when it did break its own friction, it took off like a rocket.    My first introduction to ultra-tiny cheap motors without gearheads = not worth the fight.    Simply not enough torque, let alone the high RPM issues.

What's surprised me is that the design and possibly the manufacturer of the Kato-sized 12v motor went so mainstream with Bachmann.  You can say whatever you want about these kind of motors, but they are OEM now in some pretty well-respected product.   With double-reduction gears in the trucks, the 44-tonner has decent slow speed as well.  For a while Bachmann had the motors on their parts website and I picked up a couple.

[mmagliaro]

Randy,
Do you really find that those small Gizmoszone motors (like the 3V ones)  last?    When I tried them, I found that they could run for 10 hours,
maybe 20 at most, and then the brushes would be burned right out of them.   That's what prompted me to
marry a Mashima 1015 to the plastic gearhead.
BTW, everyone still realizes you can buy that as a unit from Gizmoszone or from micro-loco-motion for about $45, right?
That's about the cheapest 5:1 reduction with a good quality motor you are going to find these days.   Going to
Maxon/Faulhaber will double or triple that price.   Those solutions are more powerful, quieter, and their output shaft
bearings can take direct loading from a worm, however.

Tim
On the "mid-grade" motors you list in your diagram
 Mashima, Kato, Bachmann,

I would put it more like:

Mashima

     Kato
         Bachmann

The Mashimas are a definite step above the others in power, low-end torque, and smoothness.

[randgust]

Funny thing you should mention that Max.   My first attempt to power my HVRR 2-6-0 was to use a Mashima plus gearhead and it really didn't work well.   I then dropped back to the Kato 11-105 with the gearhead and it's worked great ever since.    I thought I'd get controllable torque with a bigger 12v motor and found out I was better with a smaller 12v motor and a gearhead.    Excellent torque, hardly measurable draw, no heat, full slip without a noticeable drop in motor RPM, very little noise.

I think part of the issue with the brushes is how much current you're hitting the motor with.   With one of those gearheads, it's almost imperceptible.   I don't really run my stuff hard.  It's not like it's running Ntrak loops.   These are industrial critters and small switchers, not road locomotives I'm tinkering with.   The 2-6-0 is the closest I've done to a continuous-running application.

The only motors I've had deteriorate on me have been the Tomytec critter motors (which look suspiciously similar to the ones in some Bachmann applications) bigger, but still in the pager motor grade and do have finger brushes.  Those have been very inconsistent in quality.     Replacing those is how I got started with the gearhead tests.  From what I could see the brushes overheated and the metal was untempered; that's all she wrote.   

I have had good luck with Faulhaber 0816's with a dropping resistor; they still have great torque at low RPM and are nearly dead silent.  But I recently changed the one out I had in my 28-ton shay with the Solarbotics GM15 so I could get the Shay-type top speed of 8mph instead of the rocket top speed with a 0816 when there was no room for a gearhead.

Bluntly, I always buy spares, and because I'm always connecting to a universal, swapping a motor out with a gearhead is no big deal.   I've changed motor and gearhead packages three times in the 2-6-0, three times in one of the Whitcombs, twice in the Shay, and twice in two of my own Climax 18-tonners.  But after all the tinkering I'll still use the Kato 12v+Gizmoszone gearhead combo as the first choice even over the Faulhaber.   I have two applications with a pure Faulhaber, the original 44-tonner and my 30-ton Climax B.   On the Climax B I really needed the stiffness of the metal shaft to mount a second worm on to power the jackshaft, you can't do that with the Gizmos.

[timwatson]

Thanks Ian and Max for the encouragement. Thank you everyone else for the comments. Remember I'm not here to fill in the mid level range anymore. Randy, Max and Chris S have all been there done that. I really am trying to come up with an inexpensive alternative. So if your combined costs go over $20 then I don't think it's really viable for the "low range".

Pete/Max I believe you are correct in your assertion of not being able to get a $5 gear motor to be a viable option (I think Max is saying the same thing too - I believe you are all correct here). The motor itself costs $5 and every option I've explored has some other cost associated with it to augment the life of these motors. So we don't really need any more assertions that the $5 price is unreachable. I think those comments are all correct. Realistically I would think we are in the $10-20$ range as being realistic. This is an inclusive cost of motor + gear heads + costs of the items to augment the motors.

It has already been proven that you cannot use the $5 Sanyo motor/gearhead (Max did this much earlier than me in his A-board thread). These fail at 9v at approx 40+ hours. Dropping the voltage to 6v will result in them lasting longer (my 65 hr result) but the brushes still wear out.

Remember 100 hours was the goal.

So the next test with these Sanyo motor/gearheads will be centered around making the $5 Sanyo motor brushes last.

There is new news here. I have a solution that is more piecemeal. It involves the following.

Let's call this the 9v Bachmann look alike solution:
The motor is 10mm wide (flat side) x 12mm (oval width) x 15mm long. It has a double axle which is really good for adding worms and can even have a flywheel added - so it's versatile. It is only 3 pole but it does have very good performance for the price. You can buy 2 of them for $5.99 which brings the motor cost to $3/motor.

http://www.ebay.com/itm/9V-15000rpm-Brush-DC-Motor-Dual-Shaft-2pcs/151365431639

The motor itself resembles the Bachmann 2-6-6-2 BUT BEFORE YOU START THRASHING ME - there is one very important difference between this motor and the Bachmann motor. This motor has a silver commutator as opposed to the copper commutator the Bachmann had.

My test results:
I have successfully run this motor at 9v for 120 hours and the below photos show the before and after pictures of the motor. I didn't run this motor with any gear head because I found out about these motors before I had the gear head epiphany. These motors are very very good motors for the price.


Motor brushes before


The motor brushes after 120 hours @ 9v


Motor commutator before running


The motor commutator after 120 hours @ 9v

So couple this with the http://www.ebay.com/itm/12mm-Gearbox-DC-3V-60RPM-Output-Cylindrical-Electric-Speed-Reduce-Geared-Motor-/311024919557 3:1 Chinese gear head or any of the gear heads presented here so far and you have:

$3 9v Bachmann lookalike motor + $11 for the Chinese motor 3:1 gear head mod for a total cost of $14

If you want to use the 10:1 Sanyo gear head mod the cost is almost half.

$3 9v Bachmann lookalike motor + $5 for the Sanyo motor gear head for a total cost of $8

So we don't really need anymore "I doubt this can be done" type of posts. It CAN be done. I'd love others to pick up this knowledge and start taking it further.

My personal ultimate goal is to get a single solution that is in the price range of the $5-$20 range that's simple to execute.
The singular solution would be buy one motor gear head combo and have one motor brush augmentation solution that's simple for an average modeler to perform.

I personally have followed most all of your suggestions (at some point in time - for previous remotors) - but most all of the previously mentioned solutions start at ~$30 or more. I don't believe these should be in that low price range. So let's define the ranges in monetary terms.

Low: $5-$20
Mid: $25-$40 (this area has the biggest range of performance increase decrease - as Max points out)
High: $45- on up
(there is $5 wiggle room between categories - this is just a guideline to help categorize these solutions)

Having shown the above motor results you can feasibly get a motor gear head combo for less than $10.
So how does the piecemeal solution perform? It's pudding time.

I'll post a Flickr video instead and put the YouTube up later.
https://www.flickr.com/photos/nscalerail/14810058934/in/photostream/
https://www.flickr.com/photos/nscalerail/14625849738/in/photostream/
Please excuse my "god finger", like I said, the mechanism is "loose". In reverse the side gears kept getting stuck.

The movie is of a secondhand Roco 0-6-0 mechanism I had picked up (the mechanism is real "loose" so it will exhibit some wobble from side to side but that's not motor performance). I am not sure of the mechanisms gear ratio. This uses the 9v Bachmann look alike motor and the Sayama 10:1 round gear head mentioned by Pete. Total cost of this solution was $14 - $3 motor, $11 motor gear head. It runs at a scale 23 miles per hour - which is perfect for such a tiny switcher.

Youtube movie link is coming in my next post. Stiff upper lip gents there will be options for the "low end".

[peteski]

The motor you just presented has carbon brushes. That is the main reason it outlasts the motors with metal finger brushes.

[timwatson]

The motor you just presented has carbon brushes. That is the main reason it outlasts the motors with metal finger brushes.

Yes it has carbon brushes but this is still in the "low range" no? I think it's still a viable solution.
Remember I stated I wanted to have a single simple solution - more to come on the finger brush enhancements.

[timwatson]

Here is the Youtube link. Hoping this will pop in when it's ready.

[peteski]

Yes it has carbon brushes but this is still in the "low range" no? I think it's still a viable solution.

I agree.

[victor miranda]

buying a gearbox is a good solution.

from the little work I tried on small motors and big reduction gearboxes,
you may want to get a small flywheel on there.
If the motor is double shafted, it is well worth the small effort.

At a final reduction of around and more than 45 to 1, you will notice adding a small one.
the slow speeds are more even and reliable.

I've been trying to find a way to solder a carbon brush to a 'finger'
and have not been successful so far.
copper plating does not hang onto the brush...

this is because I have not met a coreless with carbon/copper blocks.
(don't mean they don't exist, just ain't met it)

victor

[timwatson]

Thanks Victor for the flywheel suggestion. That will definitely be an addition I want to try to the tiny Roco switcher.
Testing will resume "soon". I just received new phosphor bronze wire for the brush modifications.

I think I'm going to start with the .025 and .015 in 2 different motors. The current motor brush thickness on these motors is only .008" so it's really no wonder they wear out so quickly. So the plan is to make a "backup brush system". The commutator is silver so using a thicker stock should be ok against wear. Solder the bronze wire to the back of the thin brushes and then see how it wears. Fingers crossed.