Who is interested in a groupbuy of Mark Kelly's DC controller PCB and related parts

[Mark Kelly]

OK here are images of the silkscreen for the controller board :

An externally hosted image should be here but it was not working when we last tested it.

And for the adjustment board:

An externally hosted image should be here but it was not working when we last tested it.

They are connected via the three pin connectors at X4 and X6 .

 

[Mark Kelly]

More detail at

Web page on construction of kit

Which will be progressively updated with phots etc.

 

[john2]

Please put me down for both boards plus any componants. No motor. I will pay via PayPal-if that's OK.

Many thanks

 

[Bas Horneman]

john2 and anyone else who has shown interest:

I'm collecting the paypal email addresses for Mark Kelly.
The MK groupbuy is for pcb and if you want, the parts as well.

PCB:20 us$
PARTS:80 us$

In the header of your email please put "Mark Kelly Controller"
Please send me your

DiyAudio username:
Paypal address:
Amount of PCB:
Sets of parts to populate the PCB's:


Once I've got them all together I'll forward the data to Mark Kelly.

The Motor (and Pulley?) Groupbuy is handled by: superhkm

PS...very few have mailed me their paypal address?

 

[superhkm]

john2 and anyone else who has shown interest:
....

The Motor (and Pulley?) Groupbuy is handled by: superhkm

I'm sorry Bas, but I'm unable to source a pulley, unless I get one machined in a shop. Craft in Norway comes at a price, so I would be surprised if I could get a good one. If someone (You ;Bas ?) could post a section sketch of an appropiate pulley , I could give it a go with a skilled professional I know of.


Everyone:

The Motor Is Maxon 110191
Shipping included:

USA: 115us$
EUROPE: 106us$

You may notice that I put on an extra $2 , this is because I forgot I have to pay to get the motors shipped to me.

In the header of your email please put "Groupbuy Motor"
Please send me your

DiyAudio username:
Paypal address:
Number of motors


Thank you.

 

[markgall]

Yes, I also would like to see a pulley sketch or specifications. I may have to give it a go myself.

Mark

 

[Vinyl-Addict]

Yes, I also would like to see a pulley sketch or specifications. I may have to give it a go myself.

Mark

The pulley design is not so simple because of the mounting scheme of the Maxon motor. The mounting holes threaded into the motor body are on a rather small bolt hole circle so if your pulley diameter is larger than 0.500" (12.7mm), the pulley body will interfere with these mounting holes and a more complex pulley has to be machined. I say this in case you opt to press fit the pulley to the motor shaft and need to remove it for any reason. You may find that you cannot.
What type of belt do you want to use, flat, round, tape?

This is an image of my Maxon DC motor assembly I use with Marks DC drive.
Look closely at the where the pulley outside diameter overlaps the mounting screws for the motor. I use 2 set screws on my pulley for easy removal.

An externally hosted image should be here but it was not working when we last tested it.

 

[Lord Dubious]

Hi All
I have a few dumb questions.
I hope Mark or Vinyl-Addict can help.
1. Are the mounting screws for the motor the ones that appear to be countersunk into the circular lid of the motor housing? Is it OK to cover the mounting screws? If so, would it be OK to use a pulley of greater diameter? Then, to access the mounting screws, one would only have to remove the pulley.
2. What would be the heaviest platter that the motor/controller could reliably turn without undue strain?
3. Vinyl-Addict, what type of belt are you using?
Cheers

 

[Vinyl-Addict]

Hi All
I have a few dumb questions.
I hope Mark or Vinyl-Addict can help.
1. Are the mounting screws for the motor the ones that appear to be countersunk into the circular lid of the motor housing? Is it OK to cover the mounting screws? If so, would it be OK to use a pulley of greater diameter? Then, to access the mounting screws, one would only have to remove the pulley.
2. What would be the heaviest platter that the motor/controller could reliably turn without undue strain?
3. Vinyl-Addict, what type of belt are you using?
Cheers [
QUOTE]

I'll see if I can answer questions 1 & 3 for you. Mark will have to address #2.

1) Yes, you are correct. They are c'sunk for M2 x 0.4mm Flathead screws. As long as you don't press fit a pulley larger than 12.7mm O.D., the screws are removable without taking off the pulley. Larger than 12.7mm, I recommend you use opposing screws on the pulley.
You may be able to fudge a little larger, that's your call. Maxon has a very well documented PDF file you can access that tells you every dimension on the motor.
My pulley, as you can see, does slightly cover the screw heads.

3) The belt I am currently using is one I purchased from Turntable basics for $10. The P/N is FRM38.8. It is the longest or largest in circumference they sell. BTW, my platter is 12.240" (311mm) in diameter.

I am going to try a Mylar belt soon to see if there is a change in performance. My turntable is going through major changes in platter mass and a pretty involved inverted bearing so I want to see if mylar is a better option than a flat rubber belt. Feel free to ask any questions you like.

 

[Bas Horneman]

Hi All,

I asked Brian Cherry if we might be able to use his pulley's as used for the BIX and asked if drilling out the existing hole was/is a possible solution

This is part of his answer

the under rated pulley gets his 10 minutes of fame.
All the pulleys I've measured have runout. And this problem can be vastly worse on the sound than motor speed control. I've talked to machinists and they say it is impossible to make the pulley and then drill the hole perfectly centred. It must be done by small parts machine maker in one step process- hole and CNC body together. Also the hole must be slightly tapered to press fit. I suggest slightly barrelled with V groove top and bottom to use both thread belt (dual maybe) and tape. I've tried China, Singapore, Thailand and best result was Singapore, 2 out of 5 acceptable. A famous North American company refused to do it.

So I have yet to find the definitive solution. I thought it was just me but I've been checking other companies displays at shows and they have the same problems.

Ok that was the "bad" news. Now for the good news

I was talking to a supplier yesterday who does small precision parts for cameras and seems he is willing to try. DO you have a drawing for your pulley and how many do you need?

 

[Bas Horneman]

and a little something on the drive belt

Also got this from Brian Cherry via email.

Another thing worth finding out about is how to fuse 1/4" mylar leadout tape it doesn't come apart. It makes the best belt and delivers the full stability of the motor. All the methods I've tried drift apart after a couple weeks 24/7 running. Second best is fused nylon thread if someone can do it. You could use 2 of them for a pretty good result.

 

[Bas Horneman]

And this from the Teres site..

A precision aluminum pulley was custom machined for the Teres as off the shelf pulleys are generally not of sufficient quality for this application. The pulley is superbly concentric with a run-out spec of less than two ten-thousandths. To retain the near perfect concentricity the pulley has a friction fit on the shaft and no set-screw is used.

Who knows where Teres got theirs made ?

 

[Mark Kelly]

2. What would be the heaviest platter that the motor/controller could reliably turn without undue strain?

Cheers

Because the DC motor torque increases when it slows down it can turn virtually any platter. The greatest effect of extra platter mass is that the run up time increases - if you went to a platter of more than 10 kg you might be waiting a couple of minutes for it to run up to speed.

BTW from what I've seen of Vinyl Addict's work if anyone can make the pulley properly he can.

 

[Bas Horneman]

Also from an email by Brian Cherry.

One point about pulley material: it is important! I had samples of brass, aluminum and delrin made up.
The Delrin is easy to press fit and use but compared to the metal pulleys was lacking.
The aluminum was good in that it is very light so any run out creates less vibration at the motor. However it rings and does affect the sound.
Brass is deadest and sounds the best. Only problem is a little bit of run out can be noticed as vibration on the motor due to its higher mass. However it does make it easy to sort out the unacceptable pulleys.

 

[Bas Horneman]

BTW from what I've seen of Vinyl Addict's work if anyone can make the pulley properly he can.

Sounds good. But would you like to make 25 or so pulley's Vinyl Addict?

 

[audiofilo123]

Put me for the "deluxe version" of the Pcb + pulley + motor (is it the Maxon 110191?)

Thanks

 

[robbie]

am I too late

Hi All
am I too late to join this?

but before I send any money can I check some things.
am trying to upgradee my PTTOO using the ironless motor from permotec (rs no - 432-9765 ) but have been using a very simple variable voltage circuit.
will this kit work with this motor?

thanks
Rob

 

[superhkm]

Put me for the "deluxe version" of the Pcb + pulley + motor (is it the Maxon 110191?)

Thanks

Check earlier postings and do email-ordering.
So far I have recieved 1. ( of at least 20 cadidates )

Thanks.

hk

 

[Bas Horneman]

No need to give your name. Just follow these steps if you want to buy.

I'm collecting the paypal email addresses for Mark Kelly.
The MK groupbuy is for pcb and if you want, the parts as well.

PCB:20 us$
PARTS:80 us$

In the header of your email please put "Mark Kelly Controller"
Please send me your

DiyAudio username:
Paypal address:
Amount of PCB:
Sets of parts to populate the PCB's:

Once I've got them all together I'll forward the data to Mark Kelly.
So I'm collecting the email address...and Mark will send a payment request and handle shipping etc..

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
superhkm HANDLES THE MOTOR GROUPBUY..so please send your motor orders to him

The Motor Is Maxon 110191
Shipping included:

USA: 115us$
EUROPE: 106us$

You may notice that I put on an extra $2 , this is because I forgot I have to pay to get the motors shipped to me.

In the header of your email please put "Groupbuy Motor"
Please send me your

DiyAudio username:
Paypal address:
Number of motors
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
The pulley GB is uncertain at this moment.

 

[Vinyl-Addict]

Re: And this from the Teres site..

Who knows where Teres got theirs made ?

In the beginning they did press fit the pulleys but have also used set screws because I read a thread somewhere recently that stated that. I don't know what they currently use.
Press fitting or line to line fit may offer a very slight benefit in concentricity over a snug fit with set screws but if carefully made there should be no problem.
Anytime I make pulleys I bore the hole which is a bit of a challenge since it is only slightly under 3mm diameter but that yields the best concentricity results.
Keep in mind too that there is already 0.1mm - 0.2mm axial play on the shaft from the factory. Maxon specs a force of 80N for press fits.