Any Lenco users or other idler/direct-drive?

Mariusz · « **on:** 29 Dec 2008, 06:51 pm »

Just wondering how many AC members own idlers or direct drive turntabels?
I for one own Lenco L-75 idler.
Arm used with this TT is SME 3009 II Imp.
Cart at the moment is AT Eroica but would like to try Shure V15 or Dynavector 17d3 on the Rega or Origin Live arm.
Please share your experiences if you can.
Thanks
Mariusz

JDK1 · « **Reply #1 on:** 29 Dec 2008, 07:18 pm »

Regarding the Lenco: Not yet, I've got one on my project list - I bought a European L75 and extra motor - but I've yet to figure out what to do with the US motor (vs Europe) electrical issues. The Lenco-Lovers motor thread (i.e., conversion for the 50/60hz frequency differences) has come seemingly to a halt, and until I get the motor resolved, there is not much in it...I'm toying with selling the whole thing and moving on to "better supported" vintage makes...jonathan

Mariusz · « **Reply #2 on:** 29 Dec 2008, 07:27 pm »

What are the issues with the motor?

JDK1 · « **Reply #3 on:** 29 Dec 2008, 07:51 pm »

From what I can tell: The Euro-sourced Lenco motors and motor shaft were built to operate only in 50hz (instead of the 60hz here in U.S.) - while you can affect the current (at the motor wires) from 220 down to US level, the frequency will impair the speed control at the motorshaft. Use of a step-down converter will not impact the frequency problems - the original U.S./North America version motor and shafts are already turned correctly. Currently, the only options (that I can tell from reading the forum) are to find someone to redo the shaft grind to the correct "frequency" diameters, replace the motor assembly with a U.S. version (good luck - I've been looking on eBay for a long time), or try something else...

Wayner · « **Reply #4 on:** 29 Dec 2008, 08:16 pm »

What RPM is the motor (300?) and what is the shaft diameter?

Wayner

Mariusz · « **Reply #5 on:** 29 Dec 2008, 08:17 pm »

As far as the speed accuracy is concern, it can be re calibrated quite easily.
Have you tried contacting the Lenco Lovers advocate up in Canada?
He might get you back on the track.
I personally have no experience with Eu. motor but I encourage you to give it another shot.
As far as other tips or plinth design, I will be more then happy to share my experiences with you if you decide to prosuit with Lenco project.
I also can provide the templates for easy plinth constraction.

Regards
Mariusz

JDK1 · « **Reply #6 on:** 29 Dec 2008, 10:05 pm »

Some Lenco-Lovers Posting Thread (dealing with 60hz vs. 50hz.) - I didn't list the contributors (I cut-n-paste), but they are on the site:
(Q) If a 50 hz euro motor in North America runs too fast, why dont we use a larger idler wheel?
(A) Simply because it does not change anything - I also thought the same once, asked the same question, have been invited to do the maths, but then, I did them and understood that what matters is the diameter of the shaft and the position of the idler on the shaft and platter
(A) Trust me, find a machinist who'll reduce the motor shaft by 20%
(A) The nub of the problem is that the 50Hz motor, running on 60Hz, encounters a strange "node" state in some cases, and is not stable at 33 1/3 rpm. It depends on the mains voltage and the supplier. The US power suppliers are committed to reduce from the nominal 120V to 110V, and they are working towards that. Combine that with the fact that most US suppliers were giving 115V to 117V in the first place, and the whole thing gets messy. OTOH as the voltage reduces, the problem diminishes. You just need to move the preset notches for the lever, the stability increases.
(A) because the Lenco motor is a frequency moderated device, the transformer will do naff all, except you have to rewire the motor to use it. Nuff said - forget it.
(A) Sensible solution is change the motor. (edit) motor will have to be like for like - a 50htz as fitted to B50...

As I've indicated, the thread discussion has run down and is seemingly looking for new ideas - there was (for a short time) a service offered by Gary-Az in Arizona that was able to re-grind the motor shaft by 20%, but he/they threw in the towel - evidently the variances between units was such that quality was an issue...

Wayner · « **Reply #7 on:** 29 Dec 2008, 10:16 pm »

First, some of your math is wrong. A 50 hz motor running on 60 hz will run faster, therefore you need a smaller idler wheel, not a larger one. Next, if the motor is a synchronous motor, all of the pole positions are wrong and the motor will be eternally f'd up.

Wayner

Mariusz · « **Reply #8 on:** 29 Dec 2008, 11:15 pm »

Here is the difference between the motor shafts:

Wayner · « **Reply #9 on:** 29 Dec 2008, 11:21 pm »

50 hz motor on 60 hz will run 12 % faster than normal. That doesn't figure in the voltage problem or motor pole problem. I did go look for a 50 to 60 hz converter, but you'd be better off buying a Cadillac Escallade. aa

Wayner

RJ · « **Reply #10 on:** 29 Dec 2008, 11:50 pm »

I wonder if you could modify an inexpensive UPS to output @ 50 Hz?

Ron

orthobiz · « **Reply #11 on:** 30 Dec 2008, 04:06 am »

what about the Clearaudio Synchro?
Just plug the turntable in and modulate the Hz to change the speed.

Would a PS Audio PowerPlant also do the same?

Paul

TheChairGuy · « **Reply #12 on:** 30 Dec 2008, 04:12 am »

Quote from: orthobiz on 30 Dec 2008, 04:06 am

what about the Clearaudio Synchro?
Just plug the turntable in and modulate the Hz to change the speed.

Would a PS Audio PowerPlant also do the same?

Paul

Not sure on the Clearaudio, or PS Audio Power Plant for that matter....but the VPI SDS would not work for this application. It only has a range of + or - 10% (from 54 to 66hz).

David Plummer, who does engineering work for Sound of the Wood, could probably build a purpose-built speedbox at 50hz for you: http://www.soundofthewood.com/speedboxwhitepaper.html

John

JoshK · « **Reply #13 on:** 30 Dec 2008, 04:23 am »

I think the idea for converting 50hz to 60hz is a well understood problem. I mean, if you search for electronics on how to do it, I'm sure it'd be well documented. Its essentially the same concept as a PS Audio power regenerator, except you are changing the periodicity of the sine wave.

Function generators, as in test equipment, do the same thing. Conceptually, you recitify the AC, then you build an oscillator and amplify. I am sure there are better explanations available then my poor explanation. In fact I think I've read about the idea before on the diyaudio forums.

The side benefit is you have the chance to build a superb waveform/power supply.

Figo · « **Reply #14 on:** 30 Dec 2008, 05:12 am »

The is a machinist in AZ that will take the motor shaft from a UK lenco and turn it to the proper US version, I believe he only charges something like $20.00.

His username is AZGary on the lencolovers forums, send him a PM and he will probably help you out...

Mariusz · « **Reply #15 on:** 30 Dec 2008, 05:35 am »

Quote from: Figo on 30 Dec 2008, 05:12 am

The is a machinist in AZ that will take the motor shaft from a UK lenco and turn it to the proper US version, I believe he only charges something like $20.00.

His username is AZGary on the lencolovers forums, send him a PM and he will probably help you out...

Figo - IMO this is the best tip so far. Cheapest as well.

JDK1 · « **Reply #16 on:** 30 Dec 2008, 12:33 pm »

Hi all:
According to the Lenco forum, the regrind service is no longer available.

..It was the service that I referenced in an earlier post, but quality control issues were the problem (not on the machinist's behalf)...It was originally my idea to go this route until it went away...
- jonathan

Mariusz · « **Reply #17 on:** 30 Dec 2008, 03:25 pm »

Well then......................you have two choices:
take a chance, contact AZGary privately and see what he has to say or recommend
or try to find cheap "donor" Lenco (American version) for parts.

Mariusz

JoshK · « **Reply #18 on:** 30 Dec 2008, 05:00 pm »

How about something like this? Seems like it would be perfect.

Mariusz · « **Reply #19 on:** 30 Dec 2008, 05:49 pm »

Jonathan,
I do not want to give you false hopes but the LencoLovers member - "Sander" (up in Canada) is trying few shops to have his motor shaft up to N.A spects. It might be worth a while to send him a PM and find out what the progress is on the modifications.

Regards
Mariusz