Bent Axle

Probably a question you should direct to MTH Parts.  Without actually seeing them up close, it's hard to say.

You might contact Pat @harmonyards, he may be able to fix your drive block.

GRJ,

Have checked with MTH parts and they aren't 100% sure.  LOL.  Just thought I'd throw a line out here and see what bites.

I was hoping to make this an easy swap.  The customer may have someone who could swap wheels and axles, but 150.00 for the new drive block makes that an expensive cannibalization.  Ha!!

It would be a Herculean task to bend an axle on a Premier steam. Even the split 3/2 axles are hard to just “bend” ……..What caused the condition for a bent axle complaint? If dropped, more than likely has a damaged driver ( wheel ) I may have spare drivers here. This is a repairable drive block. I would not discard unless multiple drivers damaged beyond repair.

Pat

@harmonyards posted:

It would be a Herculean task to bend an axle on a Premier steam. Even the split 3/2 axles are hard to just “bend” ……..What caused the condition for a bent axle complaint? If dropped, more than likely has a damaged driver ( wheel ) I may have spare drivers here. This is a repairable drive block. I would not discard unless multiple drivers damaged beyond repair.

Pat

I was wondering the same thing. How in the world does someone manage to bend an axle on a steam engine like this one? 😳 Even if it was dropped, an extraordinary amount of force would have to act on it to bend the axle. Not to mention the likely damage incurred by one of the driving wheel(s).

How does this happen? 🤔

Trying to regauge it. 

@Charly posted:

Trying to regauge it. 

Regauge it???….with what?? ……….A 20-ton shop press??

Pat

@harmonyards posted:

It would be a Herculean task to bend an axle on a Premier steam. Even the split 3/2 axles are hard to just “bend” ……..What caused the condition for a bent axle complaint? If dropped, more than likely has a damaged driver ( wheel ) I may have spare drivers here. This is a repairable drive block. I would not discard unless multiple drivers damaged beyond repair.

Pat

I would be happy to put you and my customer in touch.  I've not had much luck in getting spare axles, gears, and drivers from MTH and this is a 2 rail locomotive.  If you think you can help, let me know. 

@harmonyards posted:

Regauge it???….with what?? ……….A 20-ton shop press??

Pat

I didn't ask...

Curious why your customer attempted to regauge it? …….MTH always did pretty good with 2 rail locomotives, …..I’m guessing the long locomotive didn’t like his layout for whatever reason, and perhaps he attempted to squeeze the wheel set in more for added clearance …..but if he bent the axle in the process, he’s my hero!.…not easy to bend those axles without removing it from the frame and whaling on it with a ball peen hammer……MTH 2 rail parts are few & far between, I can tell you that first hand….So your customer better hope & pray it is a bent axle, …..I have plenty of harvested used axles …..2 rail drivers, not so many, …..as long as he hasn’t destroyed the wheel, I might can save it, ….I’d have to have it front of me to make a determination and a path for remedy ……

Pat

Well (think of Jack Benny)  It so happens that you have been recommended to me as a possible connection for this very problem.  I just checked you profile and you're email address was forwarded to me by MTH.  So...

If it is ok with you I will provide my customer with said email address and let him reach out to you directly.

OKay?

That’ll be fine

Pat

Thank you...

I wonder if they're trying to make it p48?

@Engineer-Joe posted:

I wonder if they're trying to make it p48?

No.  It was a derailing problem that only this engine was experiencing.

Pat,

Customer is Mike Bolanowski and I have given him your email.

Again, thanks so much.

@Engineer-Joe posted:

I wonder if they're trying to make it p48?

@Charly posted:

No.  It was a derailing problem that only this engine was experiencing.

My money is this engine is/was too long for his layout, ……problem is, modifying it for one spot, or one specific curve arrangement leads to issues elsewhere…….We’ll see if the owner gets a hold of me, and find out the exact issue, & what led to the damage done.

Pat

Cheryl...

I have this engine.  Don't ask my why...I can't remember.  I bought it in the early-day excitement of the 'new kid on the block' (MTH), I wasn't into O3R at that time (lingering in the dark side of HO), a non-brass, affordable Santa Fe big steamer...if nothing else it would grace a shelf somewhere in the house.  How long ago was that??  Hadn't retired from GM yet, Rider's Hobby Shop was still on Corunna Road...looooong time ago...about 30+ years so?

Anyhow, I unboxed it to check the drivers.  All four of the flanged sets are identically gauged. (Do not have a NMRA O wheel gauge tool)  Each driver axle has about 1/32" total side-to-side play...the first and fourth axle no more, no less than axles 2 &3.  The wheelbase measures about 5-5/16".  The drivers are NOT sprung, of course, which could be sensitive to any horizontal track irregularities/transitions.  The box clearly states that this model requires a 72" RADIUS curve (which would be O144 in O3R curvature parlance, FWIW)

I only have a few pieces of old Atlas (Roco?) O2R straight track, nary a curve of any radius.   I have no idea whether the 72" radius minimum callout is marginal at its least, or whether it has a bit of 'wink-wink' dialed into the spec..   Any kink in the minimum track curvature could be a derailment trigger.

However, having this engine in hand, and seeing how little track curvature is accommodated in the driver/block, I'm inclined to agree with Pat...this beastie needs major radius curves in excess of 72" to operate reliably.  Your customer might be expecting the engine to deliver more than it was designed for.  Just a guess.

IMHO, of course.  And FWIW, always.

-----------------------

BTW...a few short months ago I believe I posted a thought on the Forum considering this engine as a perfect test installation candidate for a Dead-Rail conversion...Batt power, DCC, sound.  The tender is humongous!!...perfect for ingesting the pieces to the puzzle.   Except for synchronous chuffing-puffing smoke.  It's on 'the list'...but not moving up very fast.

Later.

KD

Although there are no NMRA-style standards for 3-rail O, I've personally found MTH locos to be gauged wide, i.e., tighter to the rail in curves than comparable products from other brands.  For example, I had a Premier Greenbrier 20-3035-1 that was rated for O54.  Even in O72 curves, the flanges of the front and rear driving wheel sets were pretty much wedged against the railhead.  The increased friction when entering a curve caused the loco to slow down, or even stall if it was already travelling less than about 9 scale mph.  But if I remove the front truck, my 3rd Rail Greenbrier can make it around O42 without slowing appreciably.  As KD observed, there's almost no side play or "wiggle room" in the MTH drive block.

Heavy weight, rubber tires on both sides of the last axle, and one-piece side rods all probably contributed to the MTH's binding and slowing.  Of course 2-rail locos wouldn't have rubber tires.  If the owner could somehow replace that one-piece main rod with individual connecting rods as on the prototype, that might help the loco make better use of what little side-to-side play there is.  (Unlike MTH, most brass locos are sprung and MUST have segmented rods for the springing to function at all.)

I've also heard multiple reports that MTH flanges tend to wear sharp with heavy use.  Some of that is because they used a relatively soft material.  But tight gauging and operation on smallish home layout curves probably makes the issue worse.  Caveat emptor.  Whenever I consider an MTH loco, I always go up one curve size from the rated minimum because of all this.

FWIW the layout in question is a long established club layout and I'm pretty sure the problem resided in the engine.  There have been GS-4 engines ran without incident.