Well, I thought I had it all figured it out…and I did. I was able to get my bridge to spin using an old transformer, and was also able to use a DPDT to control palarity for the track. But as I go to install the turntable permanently, its giving me a major headache. Basically, it only wants to work, when it wants to. Sometimes power will get to the track, and sometimes not. I actually cut an access hole into the control mounting plate to ensure the connections remained good. I’ve taken the control mounting plate off a few times, to ensure everything is seated right, and also cleaned the brass contacts. Also, the rotation of the actual bridge is terrible at best. It appears to skip gears, and when I try to change direction with my DPDT, it moves a little bit then seems to bind up and stops.
Has anyone else had similar problems like mine with the Walthers 90’ kit turntable (933-3171)?..I hate to say it, but should I throw in the towel so to speak and purchase the Walthers already-assembled turntable for $200+. If so, does that turntable ACTUALLY work good?
I can feel your pain! The Walthers 90’ TT ‘kit’ many times has warped parts and is quite unreliable. I married mine with an Atlas TT underneath it and a real metal bearing to replace the plastic parts. It runs good, but of course indexes at 15 degrees and even with a sound insulated Atlas TT underneath - there is a lot of ‘sound’ when it moves. I had close to $100 of materials in that sucker:
About 2 years ago, I bit the bullet and bought the new assembled 90’ turntable for about $200 from a dealer on eBay. It runs perfect, is quiet, and indexes as advertised. Turntables are one of those ‘precision’ gadgets that are not easy to build by most hobbyist’s. A man has to know his limits - It was the best $200 I have ever spent on trains!
I had to do a bunch of sanding on the ends of the bridge where it scraped the pit wall in a couple of spots. (down by where the wheels are) Pull your motor and make sure the bridge spins freely before messing with the motor. Mine worked great till I glued the large gear in place. I broke the gear loose and let it float. Check for flash on the gear teeth.
I also drilled the mounting holes in the motor a little larger so I could move it closer to the large gear and get the gear lash a little tighter.
Make sure the pit isn’t in a bind in it’s hole. This will cause it to be out of round.
You probably won’t get it perfect. It depends on how much stutter your willing to put up with to save $200.
I got mine to work reasonably well. I too, took it apart many times. I spent a lot of time working with the contact brushes to get them to keep enough tension on the contact ring. I trimmed and shaped the brushes so they would work. It was trial and error. I also found that most of the binding in the mechanism came from slight distortion in base. I found that the hole in my layout was slightly distorting the base. I also put powdered graphite under the bridge. I smoothed some of the contact surfaces with 600 grit wet dry sandpaper. I played around with different washers but I don’t remember how that ended up.
Originally, I was using an 8 or 9 volt power supply, it works better with a 12 volt supply. I thought that it would move slower at the lower voltage, it does, but the binding was worse.
Good luck, If I was doing it over I think I would go for the $200 one or look at some of the other pricier options.
I’m going to give it another shot and try some of the things you mentioned. I was already thinking about changing the shape of the contact brushes…I think the plastic gasket in between the brass rings prevents good contact…so maybe thinning the brushes will help, along with greater tension…if possible. I’ll also try the graphite idea…I use that a lot on my guitars (nut), enabling free movement for the strings. Hopefully it helps for the gears on the turntable as well.
Unfortunately, aside from the kit and all that goes along with it…I’ve also purchased and opened the roundhouse kit. Just seems like if this doesn’t work, I may be forced to purchase the already built TT.
As I was building the kit, I had already sanded the ends of the bridge and got the bridge to swing freely. And there doesn’t appear to be any flash within the gear teeth. I think I might cut a hole out of the contol panel so I can see the gears work in action…that should help me understand it better. Also, the hole in my benchwork is decent for the pit…I don’t think its binding whatsoever in that respect.
I found the method of fastening the copper wipers to leave something to be desired. I didn’t have any confidence in them, so I ended up placing a styrene spacer about 1/16" more in diameter than the brass rings between the brass rings. I am not suggesting that this is your problem, but I felt the top one, or both, could fall below the rings without a retainer.
My motor worked perfectly, but not without shimming it with cardstock behind it to force it to mesh properly with the large black ring-gear.
You may have a broken solder someplace, broken wires…you’ll have to do a series of continuity tests to determine where the power is dropping out from rail top to the bus wires.
Hello I have that one also. I got rid of the brushis and raped wire around the brass rings worked a lot better for me. The hole was out of round sanded it out and the bridge ends to fix most of the shuter. Glued my drive grear on and it brook free put in a set screw to fix that. Have and old train set power pack to turn it and that works fine. Hope this helps Frank
Interesting on the wrapped wire idea. The brushes just don’t seem to work well. Although the jury is still out there on getting it to work by reshaping (narrowing) the ends that contact the brass rings. As far as wrapping wire though…did you wrap it around the brass rings a few turns, then just solder or attach the wires to the bolts/nuts that were used for the brushes?
As in previous threads on this subject, and btw I understand your pain… been there done that… all I can say is buying the ready -to -run version is the best thing I’ve done in layout building. For the price of a couple of dcc/sound locomotives the higher priced turntable works as advertised… without the frustration.
Do yourself a big favor, cut your losses right now and throw that piece of junk in the garbage. Because thats where garbage belongs.I built that kit about 4 years a go and it is horrific at best, I spent months trying to make it work even went as far as machining my own ring gear after having Walthers send me tow replacements. The shaft where the bridge mouths through the pit must have been designed by a 5 year old.
I had seen an ingenus idea in MR a long time a go where a guy used a stereo jack as the pivot and the female end mounted to the bottom of the pit, that’s how he transferred power up to the bridge no silling rings and flimsy tabs.
As mentioned bite the bullet and buy the built up one. Keep it clean and you’ll be happy that you spent the moeny trust me.
It would appear the only way to help you out would be to offer you a part time job so you can pay for a new Walthers turntable. I tried all kinds of schemes to scratchbuild turntables, finally broke down and bought the Walthers Kit turntable you are attempting to get working. After untold time and over the years attempting to scratchbuild turntables at least twice I sprung for the new Walthers “RTR” turntable and you know what? It is the best thing since sliced bread. It is well worth the price in my oppinion. I have not had a lick of trouble with my walthers TT, and it has been operating now since they introduced them. I also might say that the only other thing that I have been working on for many years is a Kemtron Mogul, which rolls very nicely, and it is almost done, I just got to put a motor in it and paint it. Now if I can do that you would think a simple turntable would be a piece of cake…
I am not looking for trouble but the question begs to be asked… Is the built up unit made from different parts? Why would the built up work better? Someone had to assemble that unit. I doubt that an assembly person could do better than you guys…sooooooooooo. What is the difference?
The ‘Built Up’ TT is completely different - It is not an ‘assembled’ version of the ‘kit’ one. The only issue with the ‘Built Up’ one is if you get sand/ballast in the pit - The gearing does not like it! There is a ring of notches around the interior of the pit. The TT bridge 'walks around on that ring. Actually, it is very easy to lift the bridge out and vacuum out the pit.
Hello I just wrapped the wire around once and then I ran it to the incoming track power. I god rid of the brush’s and the mount. The wire is tight enough to stay put on the brass ring but still lets it’s spin with out binding.Hope this helps Frank
SCRAP IT!!! I spent hours trying to get it working after it was installed, removed and reinstalled many times. I thought I had the problem when I took it to a man that can fix anything, but the TT stumped him. I tossed it in the trash and now have an Atlas TT that works, although it is not 90’ and does not have all the bells and whistles it does serve my needs.
I found a quick and cheap answer to the dirt & grit in the pit problem, I stole or I mean appropriated a plastic cake topper from my wife’s very extensive Tupperware collection. When the railroad is not in use I pop the topper over the pit and it keeps all the crud put f there and everything is nice & clean & happy when it comes time to run trains
Also in regards to the original Walthers T/T kit. I know a very respected modeler who virtually gave away a diamond scale turntable because it was noting but problems. So if a diamond scale is considered junk then how can the Walthers El Cheapo be anything but.
I must have lucked out and gotten a good one or the new run or something.[%-)] Mine was a challenge to build, but nothing that made me think of trashing it. I doubt that my skills are any better than any of you folks.