Remotoring Athearn F7

Model Railroader General Discussion (Model Railroader)
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I’ve been working on a Bowser/Cary H16-44, (see http://cs.trains.com/mrr/f/13/t/282489.aspx) which uses an Athearn F7 frame. I had an Athearn F7 dummy and a damaged Proto 1000 C-Liner, so I thought I would use the trucks and motor for this project. I had some spare Proto 1000 F3 Driveshafts, which seemed to be the right length.

I found an old thread, http://cs.trains.com/mrr/f/88/t/208603.aspx , with some pictures of an Athearn remotoring by Jeffrey Wimberly. It looks like he just held the motor down with RTV silicone.

I need to mount the motor vertically, though, so I made a simple mount with styrene, and held it in place with a ziptie:

The motor is sitting on the frame in front, so it’s not quite level. It seems to run ok, but it’s a little noisier, probably because the motor is right on the frame. I’m thinking of grinding out the frame a bit so the motor is level, putting some silicone down, and sticking the motor in. This would eliminate the ziptie and cushion the motor a bit. Or I could leave well enough alone…

Should the motor and driveshafts all be aligned? If so, any problems with my plan?

EDIT: Can’t get links to display correctly. Giving up.

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The only link I could copy and paste with results, is the link to your other thread.

The two links to Jeffrey’s post go to “File not found”, and Group not found.

There is a hokus-pokus you have to do with brackets and “url” to get links to threads in this forum, to be live.

But anyway! looks like a nice project. I think the noise will be less with the motor on some type of mounts, and have the drive shafts aligned with the truck worm gear.

I can’t tell in your photo, even after enlarging it, if your drive shafts are the spline type, or the dog bone/hex type.

The spline type is the noisiest.

Mike.

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Gary,

there can be several causes for noisy locomotive. Sometimes it takes a lot of effort to make locomotive little quieter.

Driveshafts are of course one of them. It would be better if they are aligned with motor, although until certain angle, they should work without excessive noise. You can try to hold motor flat, and then observe if noise is lower.

Then, if any part of driveshaft is not perfectly centered, this also can generate a noise, due to fast spinning of these parts. If cup or ball, or any other part is off center, it can generate noise. Flywheels also - they should be perfectly balanced. If motor shaft has excessive play (radial, axial), this also can be a cause.

Furthermore, if worm shafts have radial play, they can be very noisy too.

Recently, I have started to work on Life Like E9 (SP). Beautiful locomotive. But relatively noisy, compared to other locomotives I have, especially those where I replaced original iron core motor with coreless one.

First I realized that original motor shaft had huge radial and axial play, which combined with very heavy flywheels caused a lot of noise, even the track “floor” vibrated when locomotive was running. After I replaced motor with practically noiseless Escap coreless motor, locomotive still had a lot of noise. I noticed that driveshaft cups (NWSL) are not perfectly centered. At high speed, ball and cup create a lot of noise. Ok, I found cups that are better than the other, so this part was over. During that process, I replaced solid steel shaft for driveshafts with steel pipe of the same diameter, because it is lighter, so if it is off center it will vibrate less, and noise will be lower.

Then I finally found third cause for noise. The worm shaft in both trucks had large radial play, and this was also a cause for noise. I inserted brass shim, and vibrations/noise lowered.

The rest of noise I could not remove - thin gears in partially opened gea

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I used that exact frame for a project. I bought the Stewart branded locomotive because I thought it would have a Kato frame… nope… a modified Athearn F7 frame.

I remotored mine with a Northest Shortline kit with a single flywheel specifically made for narrow hood Athearn models. It came with drive shafts and universals and work perfectly.

I held the motor in place with PSI Kneadatite Blue/Yellow epoxy putty.

-Kevin

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Thanks for the info. It’s not excessively noisy–it’s not as loud as a stock Athearn-- just noisier than the Proto 1K C-liner it came out of. That model the motor is held between two rubber motor mounts in the frame, though. The big metal shell is basically a sound chamber, though, so it’s much louder with the shell on.

I ground the frame out a bit so the motor sits level, and that quieted it down some. Silicone will cusion it a bit, so the motor noise doesn’t go right to the frame. I hope that will be enough.

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Update: I used silicone to mount the motor and let it cure. I tested it–it’s much quieter, though the shell does still amplifiy the drive noise some. I can live with it.