0-8-0 binding

I bought an Atlas 0-8-0 and remotored it. It wants to bind but only when running backwards. Any ideas?

 

How much current does it draw while running in each direction?
If it runs with no bind and low current draw forward and binds with a higher draw in reverse, it could be too much end play in your motor, more than likely it is the worm gear that is deformed on one end. Is the motor easily removable?

Al

 

I suppose I could get it out. Maybe thats the problem

 

oldrk,

These old Atlas engines have been the subject of many threads here and elsewhere. That you got one that runs at all is a surprise. Usually they bombed out after a few hours. The frame was made from an alloy called ZAMAC, and was poorly cast, leading to distortions and brittleness.

I suspect, if you do not have a frame distortion, that something's wrong in the crosshead assembly. Or perhaps the new motor changes position as different forward and reverse thrusts are placed upon it, as alhoop suggested.

 

oldrr,
Here's a link to a wonderful site about the Atlas 1st generation motive power.

http://members.aol.com/dgosha/

Lots of good information on disassembly, service and assembly.
If I had to make a guess, I would try to make sure the worm gear on the motor shaft is centered longitudanally over the gear driving the axles. Sounds like it may be too far forward or back on the motor shaft.

Hope this helps.
Jim

 

These can be made to run smooth with some work. I do not think it is the motor that is your problem. What I have seen is slop in all of those brass gears. If you are comfortable taking it all apart and fitting each peace by hand it will run well. You have to file the bottom flat and make sure all of the idler gears turn free. The plastic "u" pieces that hold the idler gears should keep them snug to the frame if the bottom plate is fitted correctly. PM me if more info. is wanted. I have one of these with over 100 hours on it and it still has the original motor in it. This may help.http://www.railimages.com/gallery/danhodge?page=2

 

Thanks guys

 

The problem I've seen in the 30 or so that I owned these is that the ZAMAC frame warps, twists, becomes brittle, etc. But the tenders are OK. I've "gifted" about a dozen to friends who believe they can fix them. I've remotored two--both have died due to increasing warpage of the frames.

[ January 10, 2006, 02:08 PM: Message edited by: Pete Nolan ]

 

I think my dad has one that he got while stationed on Okinawa in the mid 70's. his has a snapped frame on it, which I'm not too sure he has been able to find a replacement for. I do remember this engine ran well before the frame failure.

 

Did N Scale of Nevada make a retro frame for 0-8-0s ? They made one for Pacifics and Mikados. That would solve the frame problem if you could find one.

 

Flash,

I think they did not, although memory fades over time. I've still got about 20 of them, with half a dozen showing faint signs of life--the drivers will actually twitter a bit with a brief pulse of power. The flanges are too large for C55, so they have been put aside until I decide whether they are worth it.

 

FWIW, there are about 10-15 of these for auction on ebay right now. Here is one:


0-8-0 on ebay

They all may suffer the same malady we are discussing here, though.

 

I wish someone would come out with a new one (LL, Kato, Atlas, where are you?)

 

After following TainsNTractors advice on filing the frame of the 0-8-0 flat and making sure all idler gears and axles turn freely - you might have to carefully file out some slots - you should reinforce the retainer plate. Any gear bind can cause one of the middle two axles to push the retainer plate out and thus result in loss of wheel alignment. This requires a lot of disassembly and aggravation to fix.
I made a retainer out of 1/16" x 1/4" brass stock. Works fine but requires a lot of drilling and filing( middle retainer in photo). One just as good can be had by soldering a 3/64" brass wire down each side of the original retainer (bottom side), just don't cover the gear slots and leave room room for the screws.( right retainer in photo). The original retainer which is 0.020" thick is shown at left in photo. I cut all my retainers off just behind the rear mounting screw. This results in just a little loss of detail but sure makes removal of the motor easier.

Al

 

Thanks for the info, TrainsNTractors! Great web site.

 

Thanks Pete I do not know if you went to my railImage page or not but it also has the explosions for the other Rivi steamers there.

http://www.railimages.com/gallery/danhodge