Got it a couple of days ago but just now had a few minutes to test it. I set it up level on a couple of sets of books. Removed the clear plastic tape from the little IR eye and receiver on the bridge. Made sure the contacts looked okay. Hooked up 13 VAC (that's what my old Tech 2400 spits out). The controller panel seems to come up okay but when I go to zero the bridge it just moves a bit then stops, but not at the IR position. At that point the left and right movement arrows do nothing. If I power off the AC and turn it back on the bridge will move a bit more when doing the zero thing. Checked the gearing under the bridge for any material that might be binding it. Couldn't find anything. There is no debris in the pit or anywhere else.
Well, I think it is. The Walthers guy said it might have been because the voltage was too low. Even though 12 volts is minimum he said sometimes even 13 is barely enough. It turned out the battery in my multimeter was dying. Once I changed it and checked again the pack was putting out 16 VAC - no problem then. So I decided to try it on DC. Set it to 17 VDC. Same thing happens. I think it's a dud. :munhappy::munhappy::munhappy:
I presume you checked to make sure the fingers below the bridge are making good contact with the strips? These beasts are very finicky on the voltage necessary, and I learned, the hard way, that you really need a minimum of 15V. Make sure you are getting that, under load (many power supplies measure one thing with no load, but drop when there is a load).
I did check that Rick. They were all "pointing up" above the bottom edge of the hole, but I tweaked them up a bit anyway. Still had the problem. So I thought on what the Walthers guy said about checking for stuff in the gears. I did it again but this time I used the tip of a needle and scraped out even the tiniest flea turds worth of stuff I could see. I pulled out about half a dozen little things - but I mean these things were tiny. Popped the bridge back on and it started moving. It stopped one or twice again but this time the lights were still on, meaning I could press the button again and get it going. I let it go around the pit a few times in each direction and it seemed to get better with each spin. So I think it's okay but I am really surprised by what wimpy torque the motor has. It's like if the wind is blowing in the wrong direction the TT will stop. I did put it back on AC, BTW. It's providing a good 16.5 VAC even under load. It may get better, but as I spun it around there were still a couple of points where the motor sounded uneven. It got through though. Does yours sound exactly consistent all the way around the circle? How does your motor sound in general?
You are having symptoms of an electrical contact problem. Get some 400 or 600-grit sandpaper (or a wire brush in a dremel) and lightly sand/polish both the circular copper strips on the bottom of the bridge and the contact strips in the well. John C.
Good idea John. Now that I've gotten this far I'd hate to have to return it. I think I'll use the Dremel so as the limit the possibility of any sort of grinding dust getting generated. Did anyone's Walthers TT run like glass when they pulled it out of the box?
Mine sounds fine, and moves smoothly all the way around. I did have to clean the contacts, and bend up the outer fingers, to ensure track power. My only big problem was when the TT "died", but that was actually caused by a failing power supply. All the other auxiliary items could stand the voltage dropping, but not the TT. I've gone to the high end of the voltage range, and haven't had a problem since (except for a ballast). From your description, you might want to check the shafts leading into the stepper motor, there may be some other threads there. Cleaning the contacts can't hurt (but be gentle with the Dremel)
It’s easy to remove the cover from the drive motor. It is not a stepper motor but rather a standard permanent magnet DC motor. There is a double worm gear reduction drive under the cover that should be checked to see if it is free of debris, is aligned properly and is lubricated. With the double worn and following spur gear reduction, the drive has a tremendous amount of torque. If your drive appears to have low torque I would suspect that the worm drive gears are misaligned and binding. The inboard end of the motor has a slotted rotary counting wheel attached to the shaft. Make sure that the vanes pass through the slot in the photo detector mounted on the circuit board without any interference. The microprocessor uses this to count the turns of the motor so it can position the bridge with a great deal of accuracy. I would hesitate to use any motor tool to "polish" the slip ring contacts. They appear to be plated with a very thing coating of Gold. Any abrasive cleaning could remove the coating exposing the Copper underneath which would then be prone to corrosian. Simpling cleaning with alcohol is the safest bet. A very, very thin application of light oil would help prevent the cleaned contacts fron chattering. Bob
Mine performed well, except that it kept losing power to the track. That's why I had to adjust the fingers a bit. I cleaned all the contacts after we had a very cold damp spell, and I didn't have the heater on in the shed. I just went ahead and cleaned all the track and any electrical contacts with alcohol, to ensure no condensation induced corrosion.
Sigh. Maybe I'll just send it back. I captured the sound of it as it rotates around. Notice the slight hesitation at the very start and then what seems to be slight uneveness as it goes around. Now this is with the TT just sort of propped up on some books (it is level). It's not mounted on to anything.
Propping the turntable up on some books isn't an ideal situation. It probably isn't level at all. It needs to be mounted properly to assess whether it works or not. The mechanism of this turntable is very delicate and conditions must be ideal for the bridge to move properly.
Bob, I must have had a good eye on it because I pulled out my circular bubble level and it was almost dead on. Minor tweak with a sheet of paper folded in two and it was as good as it can get. Did you take a listen to the sound file BTW (it's only sound but we seem to have no way to post mp3 or wav files here so I had to mpg it). If that sound normal I'm going to keep it. I spoke earlier without a real investigation. I only assumed there was little torque because of the nature of how it stalled on what seemed to be the tiniest little bit of nothing in the gears. I put my finger against it now that it moves around and sure enough it has quite a bit of push to it. Even with a bit of opposite pressure with my finger the bridge keeps barreling along.
I listened to your audio and it really doesn't sound any different than mine, which has been operating just fine for 3 years. The thing is loud even in the best of circumstances, and the sound tends to "surge" back and forth as the turntable rotates. This is normal - or at least it is normal for mine. If you take a look at the following video at the 1:09 mark, you'll see mine starting to move, and if you can listen past the hissing steam sound, you'll hear the turntable motor sort of growling in the background. http://www.youtube.com/watch?v=kudjM0qjeS0 The question isn't how it sounds (it will be quieter when it is mounted and the motor is below the subroadbed - but it will still sound like a thrashing machine). The question you should ask is whether it is moving smoothly. If it is, there is likely nothing at all wrong with it. John C.
Hey that one of the ones I looked at before buying this TT! :tb-biggrin: What threw me was this one http://www.youtube.com/watch?v=cyeSUnjZzV4 Even with the engine noises obscuring this it seems like this one is whisper quiet. But mine does now seem to be running smoothly. Hmm, now that I look at that one again I noticed that I can't even hear the noise of the engine moving when it pulls off of the TT. Might be a bit misleading as to how his TT really sounds.
Sounds good to me. Very typical, and, based on your description, if the bridge moves fine, then all is well.
