Turntable project completed but need motor assistance.

[Vinyl-Addict]

I have just completed a turntable but have issues with the motor. I have tried 3 different motors, all with different results and neither of them fully satisfy me. 2 of them are Hurst AC motors and one was a SAIA-Burgess AC motor. The Saia motor was good but when I added mass to the platter (not shown in pics), it didn't have enough torque to keep the platter spinning.
The 1st Hurst motor I tried was the best but it was very noisy and had a loose upper bearing problem. I have spoken with several motor companies (Papst, Hurst, Maxon, Saia-Burgess) familiar with turntable applications but in order to get a motor from them, you have to wait weeks, and even then the price is high.
I would like to try a DC approach with controller but I am an electronic moron. I am however mechanically inclined and own a machine shop which is where I designed and built everything for this table. If anyone can build me what I need, I will trade my machining efforts for the work. You can email me or respond in this thread. I want a good motor, AC with power supply is also welcome.

[Pjotr]

The Saia motor was good but when I added mass to the platter (not shown in pics), it didn't have enough torque to keep the platter spinning.

Hi,

I don’t think the problem is the motor. Usually you need very little power to keep the platter spinning, even if it is heavy. The problem is more the bearing that has much friction. Maybe you should rethink about that. And another point:: more friction usually means more noise from the bearing.

And yes, delivery times can be very long sometimes. Ordered once a small brushless DC servo motor from Pittman and that took 12 weeks.

Just my 2 cents

[Vinyl-Addict]

Originally posted by Pjotr


Hi,

I don’t think the problem is the motor. Usually you need very little power to keep the platter spinning, even if it is heavy. The problem is more the bearing that has much friction. Maybe you should rethink about that. And another point:: more friction usually means more noise from the bearing.

And yes, delivery times can be very long sometimes. Ordered once a small brushless DC servo motor from Pittman and that took 12 weeks.

Just my 2 cents

Yes, the motor doesn't need a lot of torque but the small Saia-B motor is basically a "toy" motor with 0.9 cNm torque.
THe bearing is not my problem. It is composed of 2 sintered bronze bushings, hardened and ground shaft, and ceramic ball. All friction surfaces are ground to 8 micron finish and the bearing clearances are extremely close. The platter spins beautifully with minimum friction.
I tried all 3 motors out on my Rega P3 table before making the one you see in the picture. I did this so I would have a working and proven reference, rather than an unknown.

[Pjotr]

Ok, it was just a thought Did de P3 motor worked ok? That is a Premotec synchronous motor isn’t it?

Cheers

[Paul Dimaline]

The rather gorgeous DPS uses a Berger motor but I cant figure out which one it is.

Paul.

[Vinyl-Addict]

Originally posted by Pjotr
Ok, it was just a thought Did de P3 motor worked ok? That is a Premotec synchronous motor isn’t it?

Cheers

I didn't remove the Premotec motor from the P3 to try with my new table. What I did was use the 3 motors with my P3 table since I already knew what the P3 sounded like with its own Premotec motor. I was able to detect difference in performance from a known source. I did this prior to building this table.

[Pjotr]

Hi,

Did you already have had a look here?

http://www.turntable-power-supply.co...ly_outline.htm

Cheers

[Vinyl-Addict]

Originally posted by Pjotr
Hi,

Did you already have had a look here?

http://www.turntable-power-supply.co...ly_outline.htm

Cheers

Thanks for the link.
I have already checked that option out. I know someone who has that motor/p. supply and had trouble with it. He just sent it back to have it fixed. It is rather expensive too so I'm still looking.

[JesseG]

Hi Vinyl-Addict

Just a thought, but have you tried using the motor from a cheap japanese belt-drive tt to use while working out what you need?

You have a magnificent piece of work there, and I imagine you would like to use only the best to power it, but some of the motors supplied in 70s and 80s import tables were quite good.

And, they can be had for a few $ form any thrift store.

Another idea I have been kicking around is using a direct-drive tt motor outboard to drive the platter using the same size pulley on each end of a belt. Very high grade motor, speed controlled, and again available for $25 or $30 from a junk store.

You can email me if you want to explore this idea further.

Cheers
Jess

[Vinyl-Addict]

Well I finally got a prototype DC drive built with a Maxon motor.
It works very well and will be even better when we finetune a few things. The drive was designed by a kind gentleman in Australia. He shipped the boards to me last week and I assembled & installed everything into the housing.
The current motor is a Maxon 110191, pictured here inside the custom motor pod I machined but we are going to build an even more sophisticated drive in the near future for even greater performance.
I don't think he is a member of this forum, but thanks to him I finally have something to work with.