MDC/Roundhouse 2-8-0 drive issue

[ATSF_Ron]

Today I received a loco I won at auction, a V&T 2-8-0 #15.  I've had my eye out for #15 for a while.  I already have #5, so now I have a matching pair.  The #15 was sold "as is, untested," so I was able to get it at a very reasonable price.  Cosmetically it's a 10.  However, there is an issue with the drive.  For those who don't know, these are tender drive and use a shaft connection from the motor in the tender to turn the wheels in the loco.  They are sweet runners, both smooth and quiet.  No, they aren't Bachmann Spectrum or BLI detailed, but I don't let that bother me so much.  N scale modelers don't have many options for decent running "early steam."  I really like the dark red paint and gold leaf lettering on the V&T scheme!  The diamond stack is cool as well.

Anyway, back to the problem.  As my pics and crude drawing show, there is a crack in one of the drive line parts.  The drive shaft press fits into a hollowed out coupling on the motor shaft.  That hollowed out coupling is cracked to the point where it's missing a piece, isn't whole, and is essentially useless.  Since these aren't produced any longer, finding spare parts can be a bit#*.  I have a spare 2-6-0 that's a bit noisy, so I wouldn't mind pulling the part from said loco and using it on the V&T #15.  However...said part is plastic, and I'm not sure how tight a fit it is on these locos.  I'd rather not destroy another working loco's part to fix the cracked one.

Have any of you experienced this issue before?  If so, how did you fix it?  A simpler option is I have a B&O 2-8-0 (Athearn version) that I can use to just swap loco and tender shells, but I'd rather not do that if there are other options.  I have plans to paint the B&O version into an early SP version.

Thanks guys,

ATSF_Ron



V&T #5 with a healthy drive shaft connection.




V&T #15 with cracked coupling visible (hopefully).




Simple drawing showing, from right, motor and shaft with cracked coupling, drive shaft that press fits into coupling, and not shown to the far left would be the connection to the loco.

[nkalanaga]

If you can find a piece of brass tubing that will fit over the outside of the coupling, that should hold it together.

The question is, do you have the missing piece?

[SP-Wolf]

 - E6000

Thanks,
Wolf

[ATSF_Ron]

Sadly, I do not have the missing piece. But the idea about tubing with the same diameter is interesting. I went back and looked at Spookshow Mark’s review of the loco. He has a disassembly pic that shows the parts in question. I had forgotten that the broken piece is actually a slotted cylinder. If I can find a tube with the same outside and inside diameter I might be in luck! The slot can easily be cut with a Dremel. Time to get out the calipers…

And yes, the motor runs fine in forward & reverse.  I think the trick will be getting the broken piece off the motor shaft without harming anything 😬

Thanks guys!

[peteski]

It is plastic coupling - should come off the motor shaft without any collateral damage. It is not like trying to pull off a brass flywheel of a steel shaft.

[ATSF_Ron]

Peteski, yes it's plastic.  So a couple gentle tugs with pliers should get it off?  I've not pulled a coupling off a motor shaft before.  How are these held on?  Some kind of epoxy?  I don't have a wheel or gear puller type tool.

[peteski]

Peteski, yes it's plastic.  So a couple gentle tugs with pliers should get it off?  I've not pulled a coupling off a motor shaft before.  How are these held on?  Some kind of epoxy?  I don't have a wheel or gear puller type tool.

I have never seen anything but just pressure-fit.  No adhesive. Most (if fully exposed) can be pulled off just using fingers.  Pliers can be used too.

[ATSF_Ron]

This pic shows the wires that fit inside the drawbar.



This is the part of the drawbar where the oddly shaped wires fit to make contact with the post on loco.  There's another piece not shown that fits over this one.




Naturally, the drawbar had to be removed in order to get the wires into it without a plethora of swearing, etc.  In the process of removing the drawbar, a small plastic pin needed to be removed from the location the exacto is point to.  Even with gentle prodding from needle nosed tweezers, the pin's top popped off the actual pin.  These things are quite fragile and not to be found anywhere on the planet, except from maybe a donor loco.  Hmmm...

I know, Plan B!!


The loco and tender bodies were an easy swap with the B&O version I mentioned earlier.  There are some fine wire grabs from the smokebox to the pilot deck I need to put back, but my V&T #15 is fixed.  I like the blackened tire treads from the B&O version of this loco.  I'll have to do the same to my #5.

I haven't given up on the other mechanism.  I'll see what can be done about finding a plastic drive tube of the same size and try to replace the broken one.  But those damned drawbar pins!  Those are the fly in the ointment of this project.  Thanks for the help and suggestions everyone!

ATSF_Ron

[nkalanaga]

Replace the wipers with two wires?  There were always multiple hoses between engines and tenders.

[peteski]

Ron,
Have you looked into buying a replacement for the broken coupling from Northwest Short Line?
https://nwsl.com/collections/shaft-couplings-driveline-universals

[Lesferge]

I have worked on a few of these.  The two screws under the cab need to be removed and the frame halves gently pried apart just enough to release the drawbar pin.  A replacement pin can be made from a sewing pin, a small disc of styrene and some small heat shrink tube.  I also eliminated the sketchy pickup between tender and loco by wiring directly to the motor and having each wire contacting its frame half.    I have photos but am still not allowed to post images.   

[ATSF_Ron]

Thanks for that link, Peteski!  I thought I read somewhere that NWSL went out of business/retired so I didn't even bother looking.  I see several options after checking that link.  Just need to get some measurements off of a working sample.

@Lesferge, I'd be interested in seeing your photos once you're able to post.

[Lesferge]

I posted images on Trainboard.com.  https://www.trainboard.com/highball/index.php?media/

[ATSF_Ron]

Contacted NWSL and received a quick response detailing exactly how to find the specific part I needed.  They come on sprues with multiple sizes, so I'll have extras.  Also ordered a second sprue, since I have several of these locos.  It's only a matter of time before another one goes bad.

Shout out to Peteski again for the NWSL link.

Lesferge, thanks for the TB link.  I'll check out the pics.

[peteski]

You're welcome Ron, but a bit of a warning that this might not be a plug-n-play replacement. The size of the ball on the MDC driveshaft might not be the same as the one NWSL uses, so some additional tinkering might be required. Or  maybe it will be the same.