Stuttering Aristocraft GE UB25

[alec dawe]

I bought a very cheap Aristocraft UB 25 off eBay a couple of months ago. Very cheap was about £25.00, advertised in wrong place, etc etc.
It's fairly battered, but that's no matter because its going to end up as another FCCA Peru loco, with a scruffy and weathered colour scheme, bent handrails and steps, etc.
BUT the problem is whilst it seems to run fine with long nose leading, it stutters with the short nose first.
This must be a pick up problem I would assume. Before I start stripping it down, does anyone have experience of this, and any guide as where to start looking for the problem.
If all else fails, I suppose I could always swap the bogies!

It's in a black Aristo box, if that's any clue to age.

 

[generalboy80]

Have you tried running it off track with wires directly to the pickups to determine whether it's an electrical or a mechanical issue?

The resolution process is different, obviously, depending on which of those it is.

If it's running okay in one direction, but not the other, it does lean more towards being a mechanical problem (poor lubrication, worn gears, possibly bent gear box axles, or a million other things!)

For electrical issues, try different combinations of pickup points to see if one, or more, have become unreliable, or have failed entirely. If it runs fine with power applied directly to the pickup points then it goes back to mechanical problems.

-David Morris

 

[supagav]

The problem with the Aristo U25B is that the original version had the ends of the axles running into the sideframes and thus the whole weight of the loco was carried by these end pieces. On the newer version however, the sideframes are merely a decorative feature as the power pickups are contained within the motor blocks themselves and thus have less strain to carry.

Here is a pic of the newer style. As you can see there are four wires coming out, one pair is motor, the other is the track pickup:

On the older style, there are no screws but instead the axle continues through the wheel, and this sits into the sideframes.

If you flip it upside down you will be able to see straight away what I mean. I would start there and try to see what type of block it is. If it is an older version then it could be connection between where the axle end sits in a small metal housing and where that piece connects to the metal plate behind the sideframe itself.

I think though that the problem sounds mechanical. The older style blocks aren't great and if the unit is old and well used it may need the motor blocks to stripped down, cleaned and re-greased with a quality lubricant such as that from LGB.

Incidently the newer Aristo motor block is vast improvement over the older version. I had a similar problem with my U25 being a very poor runner, stuttering and juddering when starting off. I finally just decided to replace the motor blocks with the newer style which are available as spare parts from Aristo. I will be honest: they weren't cheap at all, but the vast improvement in the running characteristics more than makes up for it

Please let me know if I can be of any more help!

 

[Hutch]

Please keep us posted as to your progress. Don't forget the lighting boards that are directionally selected by diodes. One of them could have a short in it.