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Discussion Starter #1
These (Athearn?) flywheels came on a couple of recently purchased Varney F3's. Looks like they are built right into the small end pully. The is a hole in the outer end but a flat bladed screwdriver or Philips has no effect. Any ideas?

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Do the motors no longer work? I think what looks like it might be a screw to loosen the flywheel is really a balance slot and not connected to flywheel removal. Probably takes some kind of puller. Even if you could pull it, it does not appear that a 3 sheave pulley replacement would match wheel pulley. The close-up picture of the motor looks like the pulley on the motor is damaged, is that what your trying to replace?
 

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Discussion Starter #3
Thanks for responding.

The motor works fine, takes awhile to get the flywheel spinning up to speed, but that's normal.

This is curious. Looks like the previous owner made some major mods to the locomotive itself. Whomever did it, it's nicely done. Looks like the low speed end of the pully is part of the flywheels backplate. Normally the pully is soldered on the armatures shaft. These originally came as kits.

It looks like the flywheel has an outer shell with two ends inserted, but there is no evidence as to how they are bonded.
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Someone in know can correct but "a puller" if it's friction fit could be right.

Here's a homebrew solution I dug up.


There may be better options or tools. Mat
 

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Discussion Starter #5
Thanks, Found one on ebay, 20 bucks, I will make my own.

But this is a futile adventure. The person that did this mod didn't do their homework. The pulleys don't align and the wrong ratio was used. I used a rubber band as the drive mechanism as the factory coiled spring belt was not included. Poor substitute, the rubber band rubs on the pulley, but amazingly this thing moves albeit at glacier speed and nothing that I would have on my layout.

Only solution is to remove the flywheel and replace it with the factory Varney pulley, probably impossible to find.

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google "removing athearn flywheels", talks about just wrapping the motor in cloth and pulling real hard. I would be surprised if this worked. read and see if it makes any sense
 

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Discussion Starter #9
Thanks, I just googled Athearn Flywheels, I didn't go far enough. :(
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I think this will work with some modification. I only have to pull the flywheel back about 1/4" to align the pulleys. Then I can go to the high speed pulley on the array. I just hope the armatures shaft is long enough.
 

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To me the weight (the flywheel) is gripped only. The center pin/shaft is then pressed back through it. That's it. Unless the thing is welded on or something... It seems to me it ought to budge... Now maybe someone might consider some of that penetrating oil stuff. Not sure that's applicable or even works. My experience with this kind of thing more involves unmovable bolts or nuts. In that case a longer lever has always solved it. Not quite the same problem here. Except it all has to be not wiggly so the end of the shaft gets the force.
 

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Discussion Starter #11
The flywheel rotates around a stationary center tube friction attached to the armatures shaft. You can hold the armature in place and rotate the flywheel. Once up to speed inertia tends to dampen the inherent electrical instability of the motor offering smoother operation of the locomotive. It least that's my understanding. I'm not in favor of the thing but I'm going to make it work in the Varney. If it works for Athearn, why not.

I will have to switch to the B units frame as it offers more room for the flywheel. North/South. The previous owner had to construct a ridged platform for the motor to keep it from rotating with the drive unit. If it rotated as it goes around curves the flywheel would hit the sides of the locomotive. Points for that, but major points off for execution.

I will have to be careful not to damage the armature, those are getting hard to find.
 

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Discussion Starter #13
Yes, and it's very smooth. The whole exterior barrel is free to rotate. I'm afraid if I try to pry it off it will damage the brass enclosure for the oiling pad.

If I get it off and cannot align the pulleys I may have to have a machine shop mill me a replacement three step pulley as original Varney pulleys seem to be non-existent..
 

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my dad said in their shop they would chill pins and heat the metal with the holes before inserting the pins making it extremely difficult for the pins to fall out or be removed
 

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Ok possibly delete all previous comments!

So I'm looking at the picture again. Tell me if this is right. The flywheel is on the motor shaft but "floating". The motor itself does not spin it. Instead it indirectly spins by the pulley below it attached I believe to the wheel assembly... ?
 

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Discussion Starter #16
You got it.

The motor starts at speed, but the flywheel starts slowly then gains revolutions eventually catching up speed to match the motors shaft. Has a dampening effect.

How do you edit posts? I see no "edit" icon...…………......
 

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The 3 dots upper right brings up a pop up option. After you post. You edit and report yourself.and just report others. The report is useful if trolls appear... Although here, not so much or any problem.

As for the athearn drive... Ok I think I get it. Slowly start, slowly stop. I guess in DCC land they've removed the need because of the motor control.

But how to get it apart. Did you try contacting athearn? I'm poking around their website without much luck ...
 

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Discussion Starter #19
Thanks, I have that site on my favorite places.

It's call Hi-F (high friction) referring mainly to rubber band drives. Varney also offered them but this one has a coiled spring belt that is much more efficient.

Thanks for the que on the edit feature, I couldn't figure it out.

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