Motor replacement question for a steam loco

[stokesda]

Hi, all,

I have an old Bachmann 4-8-4 Northern with the original motor. It does run, but it seems kind of weak and doesn't have enough "oomph" for my liking and is kind of "jerky" at slow speeds. The motor/gearbox combination is in a plastic housing, which is mounted on top of the chassis sideways (i.e. motor's rotational axis is perpendicular to the loco's long axis).

I would like to replace it with a nice can motor. My LHS repair shop told me the only real way to do this is to replace the metal chassis and motor with a retrofit kit (i.e. new chassis and motor) from Bowser. Unfortunately, this is kind of pricey, so I'd rather just leave the loco as-is.

I can't help but think there's got to be another less expensive way to do this. Has anybody had any experience replacing motors like this? If so, how difficult is it and what kind of parts do I need? Since a new can motor would be mounted 90 degrees off the current arrangement, I suspect some kind of worm gear arrangement would be necessary to turn the gears.

Thanks in advance for any suggestions or advice.

Cheers,

[cacole]

I have the same problem with an old Mantua 4-6-2 that may be over 50 years old now. It needs a new motor, but the original motor is so narrow that a suitable replacement can't be found. The motor is screwed to the frame and sits between the rear drivers, so it is narrower than a can motor.

[Anonymous]

I had a similar drive in an older Bachmann Mikado. This drive uses a split frame (one side picks-up positive the other negative. The frame is where all the weight is. If you start hacking up the frame to install a can motor, the traction will suffer. Have you tried going to Bachman to see if they still offer this motor? Personally I did not care for this set-up and if I had kept the loco, I'd of gone with the Bowser unit. The mike I had sounded like a grinder when running.

[areibel]

Order a catalog from North West Short Line, If anyone has the parts they should!
Cacole, If you look at your open frame motor, is the top long frame section the same width as the bottom? On TT locomotives, they used a small HO motor (a DC60) and milled the bottom piece so it fits between the drivers. If you can find a motor the same size, you might be able to modify it to fit? Or use a flat can motor, they come as thin as 10 mm (about 3/8 inch). You'd probably have to build a mount to hold it, or mount it in parallel to the frame with silicone and use a gear box to drive the drivers. Probably mor expensive to do it that way, but the nice thing about that is you can get a reduction in the final speed so they don't fly anymore!

[Anonymous]

I repowered one of the Bachmann Mikados.
Unless you have the time, patience and equipment, buy the Bowser chassis or send it back to Bachmann for a replacement.
There's a photo of my Mikado drive in this link.
http://www.the-gauge.com/showthread.php?t=9379
It was alot of work and it did end up light.

[andrechapelon]

QUOTE: Originally posted by cacole

I have the same problem with an old Mantua 4-6-2 that may be over 50 years old now. It needs a new motor, but the original motor is so narrow that a suitable replacement can't be found. The motor is screwed to the frame and sits between the rear drivers, so it is narrower than a can motor.

Replace it with a Helix Humper from Alliance Locomotive Products http://www.alliancelink.com/alp/photos.htm for $39.95. Scroll down and look for part #162.

If it has the small motor, it can't be 50 years old. Mantua cheapened their product around 1959/1960 when they substituted the small motor for the Pittman DC-71 and got rid of the gearbox.

'Course, the other alternative is simply to buy another 4-6-2 off eBay for parts. Despite the rather generous use of the words "vintage" and "rare", Mantua 4-6-2's are anything but. You could probably get a complete engine for less than $39.95.

Andre