I could hear the motor spinning but the wheels weren’t turning. I managed to get inside and found that there was a flexible coupling joining the flywheel to the worm gear that had broken.
It is the small part with a cross on it that fits into the flexible part. The item in question is directly left of the flywheel. Athearn doesn’t have anything like this available on there site and i assume it is probably discontinued.
When i look closely i see the item is cracked across on one side so it just spins on the shaft. Is anyone familiar with repairing these kinds of things. Or could give me advice on a suitable replacement? Or advice on the matter?
While you are probably correct, I think I would not necessarily assume they don’t have that item.
I think I would at least try contacting them to see what they might have hidden away, and see what they might suggest for a repair. And get a valid part number.
There is a good chance the problem was caused by my attempting to clean the wheels by holding the loco in place with one set of the 8 pairs of drivers/pickups on track with power. And nursing a Q-tip soaked in isopropyl alcohol to the wheels that were spinning. Part way though this procedure the wheels still spun but lost a lot of power then quit all together.
I have written to Athearn as you suggested. I have found a few examples of replacement flexible couplings in my searching. None with clear pictures that would show me if they are the correct ones. One with a vague statement from A-line stating it is for Athearn but no clarification of what kind of loco it fits. I have seen a lot of different styles in my searching and am wondering is this something i can change out the entire coupling with a new style.
I think you can come up with something with a little research. And I believe that someone already suggested contacting North West Shortline.
Concerning your wheel cleaning method, I’d suggest that you should have put the alcohol on a paper towel, put the paper on the track, run the engine onto the paper towel, and then turned on the power. I would not apply any pressure on the engine. Just let gravity do its thing.
And don’t use any alcohol more than 50%….more that could remove paint.
The traditional answer has been to try using a drop of CA or comparable adhesive on the shaft, even if the crack stays a bit open ‘naturally’. Epoxy is imho the ‘wrong’ adhesive for a close fit.
You might try 3D printing a piece (in resin, not PLA) but you will still need an accurate lathe. Turn the OD and then use that to center the shaft hole (after the manner of machining wheel boxings).
Thanks Both of you i have hear back from Athearn they sent me a couple links to possible suppliers. Ill try them while i wait to hear back from A-line/Arrow Hobbies
I was thinking about the CA glue and decided to give it a try since i didnt want to leave this baby open on the operating table for weeks waiting on answers as i would probably forget the process it took to get aspart. And it worked for about 20’ so i guess about a 1/3 scale mile till it seemed to experience a reoccurrence of the previous situation.
Try it again; if there were any gaps or cracks to be filled, the first CA application may have filled them. If you can, rough up the part of the shaft where the part goes, axially (like splines) rather than circumferentially…
… but I have to wonder: have you carefully gone through the rest of the ‘driven’ structure and confirmed there is no drag or other restriction in there? Is the worm correctly shimmed and lubricated, with no deformation of the worm-wheel teeth?
Thanks Woke yes i will give it a few days rest and come back to it again before i give up and turn it into a static display. Working on the mechanical things at a microscopic level for a day deserves a rest.
I really don’t think that “normal” CA will work. There are materials where CA doesn’t do its thing. I understand that there are CA varieties that are formulated for these materials, usually some sort of plastic.
Usually you need to clamp the two things to be joined until the CA sets.
Additionally, looking at the photo, it appears that there is a lot of grease/oil on the parts. Unless the parts are absolutely clean, nothing will work.
Thanks thats a good point regarding the clamping. I think next time i go in if i don’t have a new part solution to try i will see if i can bend up the tips of an alligator clip to do that. Though the space is quite tight to the point that i couldn’t get any kind of tool in there to try and perform some kind of axial scoring. Despite all the grease on the worm gear side of things the other end didn’t appear to have anything on it. Though if i glue again i will clean both the component and shaft with alcohol.
@Woke_Hoagland
Speaking about additional drag to the remainder of the structure i can say i never did think to try and spin the wheels or the plastic gear that sits on top of them that the brass worm turns. I did place a few drops of lube oil (That i think is the right stuff as it was purchased back in the day when a LHS existed.) I had on a few points on the wheel assembly though. But there seemed lots of grease on worm gear side of things. (And im not sure what kind of grease i could use there either so i didn’t touch that part.) I do have a good supply of a synthetic grease i use on the skid steer that is rated to perform down to -49F it is quite plyable at room temperature perhaps that would be good?
And i guess i would definitely need some pointers regarding shims.
Thanks I was watching some youtube videos on servicing locos and this was recommended in one of them too. I got my local hobby shop that is only about 1000 km away to send me an email when they get it in stock.
