Model Railroading > NWSL ball and cup universals

The project at hand is a PFM/Samhongsa NP 4-8-0.

I had test run it and it is pretty smooth so I took the body off to see if there is room for a TSU-1000 or TSU-750 decoder in the boiler. I think the larger electronics might fit if there were not all those pesky wires to deal with. It looks like the 750 with a keep alive circuit will work just fine without removing any of the boiler weight.

There is a can motor connected to the gear box with a rubber tube and it was degraded to a couple of fibers keeping it all together. So I took it out. The 2mm motor shaft has a tube bushing to bring it out to 2.5mm. The gear box shaft is under 2mm but has a bushing to bring it up to 2.5mm. The closest ball and cup NWSL has is 2.4mm. So with a fine round file I opened up the shaft openings to fit the delrin parts to the shafts. I raised the rear of the motor a bit to align the shafts.

Well, I created a meat grinder. It cogs a bit at coupling speed but smooths out at switching speed.

So are there any ways to quiet this cup and ball connection down short of ripping out the motor mount and rebuilding it with a torsion beam? Is there any flexible tubing to go back to? I can say 2.5mm is just a bit larger than 3/32".

The motor shaft bushing is short and does not reach all the way back to the back end of the cup. I am not sure that is running true. It will be a couple of weeks before the NWSL set for 2mm shafts arrives and I can try that on the motor. I suppose I will need to sweat the brass bushing off the steel motor shaft without melting the armature insulation?

Thanks.

http://www.trainorders.com/discussion/read.php?3,3471431

Posted from Windows Phone OS 7



Edited 2 time(s). Last edit at 07/25/14 22:59 by fbe.

Why didn't you just put a new coupling on using the soft neoprene model airplane fuel line? It's available in many sizes and I've used it for years. Smooths things out immensely.

Good idea but none of the fuel line available locally was small enough to do the job.

Update:

Stopped by the LHS and indeed they only stock medium and large DuBro fuel line. I was able to order the small size in a 2' length so maybe it will be here in a couple of weeks.

Posted from Windows Phone OS 7



Edited 1 time(s). Last edit at 07/26/14 12:50 by fbe.

I called a friend who has been flying R/C as nearly as long as I have been model railroading. He also has a nice HO NP steam layout so he is familiar with brass locos as well. He was kind enough to provide me with the needed fuel line so the NP X is ready for application of DCC. It is still not the quietest pufferbelly on the ready track but it has improved notably. I think the gearbox cover may be riding on the drive gear so I may try a couple of spacer washers to see if that helps.

Posted from Windows Phone OS 7



Edited 1 time(s). Last edit at 07/26/14 21:24 by fbe.