Any way to get a Weaver engine to negotiate curves?

Those old Weaver chain drive locos were designed for 2-rail O-scale and then adapted with pickup rollers for 3-rail.  They were never intended for sharp curves and it's not surprising that the universal joints bind on them.  Later RS-3's have the same dual motor setup used by Williams, MTH et. al. and those will work on 031.

It will run on O42 with an MTH Premier freight car immediately behind the loco (or any car whose couplers aren't rigidly attached to the truck.)  For O31 you'll need something with truck-mounted ("swinging") pilots.  But unless you find one of the newest ones with Legacy or PS3, you'll be giving up a LOT of your slow-speed performance.

Thanks for the tips men.  Looks like I've got my work cut out for me.  Funny thing is that Lionel, K-Line, MTH and Williams RS-3's will navigate 031. I believe that the addition of floating couplers may help somewhat and as indicated and the first car behind the loco must have the coupler draw bar not fixed to the trucks.

Hi Dennis, this is not meant to contradict the statements above, they are all very true. But, I have an old Weaver Train-master that would bind on even O-72 cures. It turned out that they routed the pickup roller wires wrong inside the engine and there was just not enough slack to negotiate the turns.

I know that was an odd-ball circumstance but I thought it was worth a mention.   

Good Luck.

The weaver engine is a scale model with a scale frame and pilot asssembly.  K-line , MTH, and Williams and Lionel RS-3s are toy trains at least in the frame, trucks, and pilots.   They are made to run on toy train curves with high speed, low-priced motors mounted in each truck and geared directly to the wheels with no reduction gearing.   

If you like the Shell, shop around for a newer weaver that the two motor truck mount drive and swap the shells.    Those newer WEavers have drives very similar to the MTH ones I have seen.   They also have the rotating pilots attached to the trucks.

Um Mario E. Weaver models never made a FM Trainmaster. Perhaps you should post a picture of what you are referencing too.

"Funny thing is that Lionel, K-Line, MTH and Williams RS-3's will navigate 031."

Dennis, these locos - and the modern Weaver RS-3's -  are made completely differently from the old chain-drive Weavers. They have 2 vertical can motors, each mounted on the truck itself. No driveshafts or chains. 

I believe the new RS3 China drive models are not scale, the hood and cab dimensions are different from the one Weaver produce (Dennis mentioned) with the horizontal drive.   Hood and cab have been altered to accommodate the China drive assembly.  My Foggy head says we did a thread on this at one time.  Dennis' model also has some pretty nice looking handrails v.s. the flat bar handrails on the current across the industry model.

New Weaver RS 3 from several years ago.

Mike CT