Teres turntable motor problems


Hi, i have an original web/kit Teres turntable that i build the armboard and base for.  The motor was upgraded from original pod to signature status 10+ years ago.

I am having intermittent issues with the motor pod.  I am running a 1/2" silk ribbon for a belt, and am getting speed problems that start and stop and also complete stops of the motor on a very random basis.  I have very lightly oiled the motor shaft and replaced the bearing motor recently, also checked the speed probe gap and cleaned that area off. 

it don't even see the teres website up anymore, so i assume the Chris Brady email there would be dead?  It also sounds like the motors are no longer available, so I am thinking worst case i need to go with a new motor system to run this table?

Scheu, Sota, Galibier, VPI, ?  The Sota option is $1500

Anyone on this forum who has already gone down this path that can give me some advice? 

thank you

Tim in Seattle.

128x128tcellis

I'm sure that there's a cap that provides a directional momentum for your motor. Replace one and see if it fixes issue.

Also I'm very new to using silk ribbon for the belt. It seems to me VERY SLIPERY to do so. Can't you use normal conventional rubber one? Teres and I'm sure many other small private manufacturer brands are indeed very temporary to the life expectancy of the owner. Once that happens, you are on your own and must take your own decisions.

I'd contact Thom at Galibier; he and Chris and Peter from Redpoint worked together prototyping those early tables, and knows a lot about their design .  More than likely there's an issue with the control electronics for the motor/sensor assembly.  Thom can work with you to upgrade your motor to one of his, which integrates the controller into the motor itself (no more external sensor).  You'd get a new belt in the process as well.

 

Good idea to work with Thom at Galibier. I also wonder whether you could adapt the SOTA Eclipse motor system to the Teres. But it’s always easy to suggest a costly remedy for what might be a problem with an inexpensive solution.

I sent an email to Thom, thanks for the suggestion.  Has anyone used the Sota total eclipse system on a non-sota table?  The Sota is $1500, the Galibier is $2745, I can't imagine a solution from VPI could be any cheaper.... 

I am using the antecedent Phoenix Engineering system, which is the Eclipse minus the motor, on my Lenco, very happily, as are many others. The only concern would be whether you can fit the Hall sensor that monitors platter speed, in between the bottom of your platter and the underlying plinth. SOTA can probably tell you how much space you need. 

Hi,  thanks for the response.  I built my table base, so i will be comfortable machining it a bit if need be.  I think from looking as the Sota info, that the magnet should fit though.  I have a 12.25" dia platter and the Sota's are different.  Do you know how the magnet (on the platter) placement is accounted for?  Do you just adjust on the "box".  I guess i am confused as how 33.33rpm, etc is nailed down, if the magnet is just placed.  i understand once it is nailed down that drift/variance will be shown.  Hope that is clear, thanks

 

In the Phoenix Engineering set-up, the sensor is set in a fixed position under the outer edge of the circle described on the surface of the plinth by the platter floating above it. Then a magnet is fixed to the underside of the platter, at its outermost edge, such that the two elements pass over each other with each complete rotation of the platter, with a certain max tolerance for the distance between them when they are momentarily superimposed. Every time the two elements are in proximity, a signal is sent to the Roadrunner (tachometer), where the speed of the platter is compared to a reference (33.333 or 45.000, depending on the setting). If the Roadrunner perceives the platter is moving a hair too slow, it sends out a signal to the voltage source (I forget the Phoenix Eng names for that device; they made two versions with different wattage ratings, so the original PE system is compatible with a wide variety of AC synch motors), which pulses the motor to speed up if that is needed. Or the motor reduces the drive force, to slow down the platter. The Roadrunner is not just monitoring speed; it is actively maintaining an exact set speed via its role in feedback to the driving amplifier. I hope this answers your question. In the Sota system, the driver amplifier is designed specifically to work with their Eclipse motor that is included in the Eclipse package.

i think the light bulb went on, my head was confusing speed and RPM. 

i think my big decision now is do i fork out about $1700 (sota=1500 + taxes,+ shipping+ new belt + new pulley) for this, or do i just go buy a used VPI or something for about $2k and sell my existing bits/arm off.  thanks for the help.

Not sure why you are giving up on your present motor unless you found out fixing it was prohibitively expensive, but the gains associated with tight speed control afforded by the SOTA Eclipse system are not trivial. In other words you’re not just getting a new motor. Whereas a used VPI also “needs” the Eclipse.

My current motor is no longer manufactured and the builder has gone out of business.  i am doing trouble shooting/tweaking of what i have now and also feeling out what my options may be.  The Sota does sound very nice and seems like it could easily install it on my own, so very tempted if i do need to go that direction

 

i did hear back from SOTA and they basically said the diameter of the teres platter would not fit within their controller adjustment range.  They mentioned a custom pulley would be needed.  They did not bring up customizing a controller or pulley for me, so at $1600+ shipped out the door and still needing customization my dream of a SOTA set up are not really working out.  Ignoring costs, i like the idea of the SOTA system the best.

 

Custom pulley should not be terribly costly. Why not ask them for a source? If they can’t do it, they may know someone who can. Or, assuming the existing pulley needs to be greater in diameter, maybe its diameter can be increased by wrapping it. Also maybe Bill Carlin(?) of Phoenix Eng can fiddle with the electronics to make it work. Sounds like all you’d need there is a different potentiometer. Bill is a nice guy.

Tcellis,  I too may be having trouble with Teres drive system on my 340. I'm not sure because it may just be the belt. I have a tendency to run the belts longer than I should. I just replaced it so haven't had opportunity to determine if this is the problem. Since I can't message you, I hope you will give us an update since it may be very beneficial for us Teres owners. Also feel free to message me to compare notes.