Walthers 90' (Troublesome) Turntable.

[jwmurrayjr]

Crandell and others mentioned "fixes" for this TT. It looks good and the price is "affordable" if you can get it to work (motorized). I've has some luck with it [B)]using a decoder to drive it (Walthers motor) but it still is not quite satisfactory.[:(!]

Please post any fixes or improvements that you know about.[:p]

Thanks a bunch!
[:)]

[selector]

What problem(s) have you encountered, Jim?

[jwmurrayjr]

The only problem that I'm having now is "jerky" movement of the bridge as it turns. I've tried adjusting the motor mounting and improved it some.

I think I've got the electrical problems (mostly related to the wipers) fixed.

Thanks,

[selector]

I have that problem, but only if I rotate in the other direction and if I let one end of the bridge enter one quadrant that seems to be tighter than the others. I will attempt to fix this by grinding down the walls a bit to see if that frees it. if not, then the problem lies in the pivot, the gear/motor interface, or the trucks under the bridge ends...they may be binding on something. That's the best I can do.

I also had to deal with wipers that wanted to climb out of their zones. I solved that by grinding each of their side edges inward by about 1/16" from about 1/4" from the blade tip until about 1/4" past where they made contact with the power rings. I also added a small styrene disk retainer at the bottom of the pivot so that the lower wiper wouldn't rotate downard over time and slip off the bottom.

I take it that your bridge doesn't wobble excessively as it rotates electrically, or when you rotate it by hand?

[jwmurrayjr]

The bridge was rubbing on the pit wall so I put a piece of fine grit emory paper between the end of the bridge and the wall and rotated it by hand until the binding stopped.

Its controlled my a mobil decoder set to address "99" and turns pretty smoothly some times but at others it seems to bind at the gears and is hard to stop right on the "money". The jerking also detracts from the realism, of course. It doesn't wobble (unless that's whats causing the jerkiness.)

[tstage]

I assume you all are talking about the older Walthers 90' turntable vs. the newer $300 motorized version that just came out?

Tom

[selector]

Yes, Tom, the older to which you have to add an optional motor drive.

I run mine of an MRC DC transformer, Jim. That unit used to run my snap switches off the AC posts, and only the turntable on the DC posts. I could control the speed of the motor wonderfully (and will still when I am back up and running in about six weeks) using that power pack, and could easily dial down the voltage to get the bridge to stop exactly where needed. I have enjoyed this aspect of model railroading immensely because of how it all turned out.

Now, if I could just get the 360 deg out of it..., then I will add the DPDT to the circuit.

[jwmurrayjr]

Crandell,

I use a DH123 to power and control the motor. The DH123 is "silent-running" and that helps a lot. The slow-speed control is fine (I was using an old MRC pack and that worked very well also but I wanted to control the TT from my walk-around DCC throttle so I could get a better view of the tracks when aligning them.)

I use an MRC DCC auto-reverser to control the "polarity" automatically.

The jerkiness in the drive is really the only problem I have now.

Thanks for the comments,

[tjerrard]

Jim

How did you wire the DH123?

Tom

[jwmurrayjr]

Tom,

I just wired the red and black leads to the DCC bus and the orange and grey to the TT motor. I use the Atlas system and had to clip the red and black to my program track to program the address (99) and make any CV changes. But if you got a newer system you may be able to "program on the main". I think that I just ended up programming start and max speed (no "momentum" gives better control.)

You could use any left-over functions to control bridge lights or roundhouse lights, etc. I haven't yet.

[tjerrard]

Jim

Thank you for the description - I shall try it on my digitrax system.

Tom

[jwmurrayjr]

Glad to be of help.

Now to get my TT to turn smoothly. Reckon I'll have to rip it out and try again.

Have fun,