UP 4-12-2 Build

[mike_lawyer]

I'm curious as well how the frame extension is attached to the main frame.  Nice work!

[RWCJr]

Blazing fast progress!! Thanks for the frequent updates, just logged on for the first time this weekend (our weekend with our 15 month old newest granddaughter AND great weather for the park playground).

[SkipGear]

Great start.

How do you plan on moving the cylinders forward enough to allow for a 4 wheel pilot truck? I think Otto's suggestion of the IHB 0-8-0 cylinders may be worth investigating before you get too deep into the boiler.

Is the boiler large enough to hide the motor setting that far forward in the loco? When I built my 2-10-2, the motor width was a consideration when it came to building the boiler. I used brass because I needed the boiler material as thin as I could get at that point to keep it close to scale width.
 

[superturbine]

Thanks for over generous comments, not sure how I am going to live up to them. As for the work I was able to get done today.  Address the cylinders moving forward I installed new Bachman cylinders which are connected by a saddle and secured at the front of the frame.  New scratch built cross heads and longer piston rods were installed.  And the valve gear was reassembled.  The pilot truck is from a Kato GS4 and use a casting of the brake holder which has the cut out for articulation of the front pilot.    Test ran engine and everything works good.

As for the cast frame addition (2 bearing boxes) being secured to the Kato frame its super glued and then epoxied.  I use the super glue with kicker to get it secured quickly when I have it in the right position.  When everything was up and running I went ahead and epoxied the frame-addition to the bottom of the motor (motor can no longer be removed).  This was done to prevent frame damaged which would be a complete “Disaster”.


I learned from my previous ATSF 2-10-2 build that I would be able to fit the boiler over the motor and frame.  For one of my 2-10-2's I had milled the frame and found that it would not be necessary.... Actually Otto did.

[mmagliaro]

Not so fast  LOL!   "Scratchbuilt crossheads"?   I want to see more pics!
Nice going man.  It really looks to be proportioned right and sure looks like it will work.

[superturbine]

Ooops,  that what happens when you have four children acting up why you are trying to type your loco build.  The line should say scratch built cross head guides.  Thanks for the correction.   

[Hornwrecker]

I'm finding myself constantly amazed by the craftsmanship that I keep seeing on this forum.

(Give me a couple of years, and I'll be pointing out the flaws that I see. : )

[Lemosteam]

Jason, that chassis looks incredible.  Sorry I did not comment sooner- I was relegated to only looking all weekend for my son's 8th birthday.

Now that you have the chassis glued up, you could drill some holes through the casting for alignment pins and then razor saw thru the casting protion to be able to separate the halves without dsrupting the axle alignment.  You could glue in a pin on one side that goes into the other half and add a spacer to fill the razor saw gap.

Would be sad if that motor crapped out on ya and you couldn't get her running again.  Awesome job on the cylinders and parts.

Working on those bits scare the crap out of me.

Cant' wait to see more because i agree with Max and others, I love the "watch me make this" threads!

[SkipGear]

I'm with John, before you get any farther, I would really consider making things serviceable. I'm not sure what kind of duty you plan on putting this thing through but the Kato motor is certainly not bulletproof. My 2-10-2 has melted the coupling loose and cooked a set of brushes in its lifetime so far. I abuse my loco though, pulling 70-80 car trains regularly. I cringe at people just talking about gluing motors in and this thing is glued together as one solid block including the motor.

If you do decide to make at least the motor removable, while you have it out, take advantage of all that space and add a larger flywheel.

[superturbine]

I would agree with you guys that i would have perfered the motor easily removeable.  I did did secure the frame addition to the motor in a way that if/ when needed the glue can be cut and the motor removed.   I have built several 2-10-2 and the frame addition could be damaged much easier on this 4-12-2 than on the not so simple drive box addition of a 2-10-2.  My larger concern is if the engine gets misshandeled and brakes apart at the frames halves. In addition, this engine will not likely ever see the service that your 2-10-2 does skipgear i do not think it will operate on most N-track layouts and my layout will only handle 30 car trains.  The good new is that the engine has been tested over a 2 hour period and no unusual heating of the motor was observed.  Also keep in mind I consider this my pilot model... I plan to build three more.  I cant over engineer any one part at this point the whole concept has to work...... not sure of the future unforseen problems I could still run into

[superturbine]

As luck would have it I have a light day of work!!

Skipgear-I do like the idea of a larger flywheel so how about a double flywheel!  I was able to drill out a bit of the stock motor shaft and install a section of shaft into both flywheel and epoxy them together. 

Here is a comparison of the 4-12-2 verse a 2-10-2 mech.  The 2-10-2 was an early test for me and I removed more of the frame than what was needed for my boiler casting of a 3800 ATSF.  With the 3800 weight was re-added using tungsten. Just thought you might want to see. 

[mmagliaro]

I am as guilty as the next guy of putting motors in with epoxy, rather than make a nice bracket. 
It's not as bad as it sounds. I can
slice out the epoxy and pull the motor out without much pain if I have to (and it has happened a few times).
If I have room, I make a bracket.  My B6 has one.  Usually, I trade off a bigger motor for the bracket.

But this is different.  The idea of the frame itself on Jason's engine being epoxied to the motor to
keep the frame stable makes me very nervous.  Jason, you say you think you can cut the epoxy and take out the motor
if need be.   I guess on that point, I'll just trust you.  I thought from the way you initially described it,
the frame add-on was glued to the motor to keep the frame stable.

Motors do fail.  I replaced a motor twice in my PRR T1 and that thing does not get lots of serious run-time.
So a frame that could come apart by removing the motor is very risky.
(That issue has long been addressed).

[superturbine]

Failure is an orphan......... while success has many fathers.


But this is different.  The idea of the frame itself on Jason's engine being epoxied to the motor to
keep the frame stable makes me very nervous.......I thought from the way you initially described it,
the frame add-on was glued to the motor to keep the frame stable.
?????
LOL-   Max- you initially understood it correct..... I think/

I do appreciate everyone’s concern and I do know it’s because I am putting so much hard work into the engine and you guys want to see this engine roll. I to do not want a motor failure, but realize there is the possibility.  I am sure that the motor can come out if there is a failure (without frame damage).  I have simulated it on other mechs today...... but not this one.  I feel that a frame joint failure is potentially a larger threat, so I have chosen to secure the frame in the additional location at the sides of the frames and edges of the motor.  I believe this in done out of necessity not laziness.

[mike_lawyer]

You might want to consider a coreless motor for this thing.  A Faulhaber 1016 with a gearhead would be virtually indestructible and could be epoxied in place.

My main concern with using the stock Mikado motor would be heat.  Get that thing going with a reasonably heavy train, and that frame is going to heat up fast.

[superturbine]

You might want to consider a coreless motor for this thing.  A Faulhaber 1016 with a gearhead would be virtually indestructible and could be epoxied in place.

My main concern with using the stock Mikado motor would be heat.  Get that thing going with a reasonably heavy train, and that frame is going to heat up fast.

I will definitely do that on the next three I build, do you think that will be the best size? and it does fit into a Kato-mech with the rear of the frame cut out I assume.