Pro-Ject Motor and SpeedBox with AR Turntables?

[JXO]

Jim JXO,
Did you not get the pm from me as I said in it I have a pulley for a Pro-ject motor that I got with a SpeedBox not a mkII modal. What is the size of the AR 45rpm pulley as the pulley I have is 15.75mm if the AR pulley is bigger the Pro-ject will not work, it also bigger size pulley 21.5mm that for 78rpm playback. Robert

Robert: got it. when the pulley comes, I will compare it to the AR pulley. I will measure the AR pulley tonight and let you know. I am with you on the concern about the pulley size and the motor speed. Am sure I could find a way to secure the AR pulley. Am still more worried about getting the speed right with this motor, pulley (whether the AR or the Pro-Ject) and drive platter combo.

[Gliding Dutchman]

Swop the pulleys...

To remove a metal pulley one has to carefully heat it with a gas flame - it will slide off. It also has to be heated when fitting it.

GD

[JXO]

Jim JXO,
... What is the size of the AR 45rpm pulley as the pulley I have is 15.75mm if the AR pulley is bigger the Pro-ject will not work,...

The AR pulley (measured from the larger/45 section):
1. Circumfrence: 3-9/16" or 90.4mm
2. Diameter
* out to the lip (easier to measure): 1-1/4" or 31.75mm
* without the lip (to the contact point of the belt): 1-1/8" or 28.7mm

Looks like the 45 section may be too large. The smaller section's diameter (with the outer lip) measures 5/16" or 23.8mm. It's possible that a custom sized pulley may be needed to work with this motor/drive platter combo. I assume, even if the AR pulley is sized differently, it may still work b/c of a different sized drive platter. I am forgetting my math, but all that matters is the rpms off the motor; if it spins at 300rpms with 60hz, the AR pulley/drive platter combo will work fine and we should get the right platter speeds.

This 2.1mm plug arrived:

http://www.partsexpress.com/pe/pshowdet ... N=59459163


The wiring on these things is less than clear but it appears to have only 2 connections-- one for the center pin and one for the outer barrel. If it all works this plug may be the most elegant solution. The existing power supply in the plinth can be easily opened; the capacitor can be easily wired between the motor and the existing switch; then the plug on the AR power cord would be replaced with this DC jack which would plug into the SpeedBox (and the extra cord length would be useful b/c the cord on the SpeedBox is very short).

[Ernie L]

Ouch. that looks painful.

Is it manual or do they get installed on a power drill?

yes hand reaming will work just fine on the top plate..if you wish to screw things up faster..errr I mean enlarge the hole faster you can use a step drill bit in your power drill. I do not not recommend this approach on something as dear as a turntable top plate
http://power-tools.hardwarestore.com/54-383-step-drill-bits.aspx

[rkay5]

Jim,
The 45rpm is not to big with motor speed with the Speedbox putting out 44.6Hz motor will tun at (44.6hz / 12 x 60 =223) 33 1/3 the pro-ject 24 pole will run at 223rpm and at 45rpm the motor will at 300rpm so you must use a pulley that is the same size as the AR 45rpm pulley . Robert

[JXO]

... so you must use a pulley that is the same size as the AR 45rpm pulley . Robert

Thanks for all you help Robert. I have been hoping that this would be the case.

Any advice on the best way to get the old AR pully to fit more snugly on the motor?? In the next few weeks I may get a new one made.

[rkay5]

Jim,
The AR pulley is a press fixed on the motor right so when you put the AR pulley on the Pro-ject motor how mush play is there if it's very litttle try a little teflon tape around the motor sharft or you can have someone drill 2 hole and tap it for 2 small allen bolts to hold the pulley.
I hope this helps Robert

[JXO]

Jim,
The AR pulley is a press fixed on the motor right so when you put the AR pulley on the Pro-ject motor how mush play is there if it's very litttle try a little teflon tape around the motor sharft or you can have someone drill 2 hole and tap it for 2 small allen bolts to hold the pulley.
I hope this helps Robert

thanks again. I will try the tape. FYI, the Project motors use a single allen bolt to lock the pulley against the motor shaft-- 2 bolts would add balance and seems the better way to go.

[JXO]

I hope to have some exciting developments soon. Stay tuned.

[ddarch]

Looking forward to it!

[rkay5]

Hi JXO,
What's going on with your motor psu upgrade let us know.
Robert

[rkay5]

Hi JXO,
What's going on with your motor psu upgrade let us know.
Robert

[misterperry]

How can we find out if JXO's 'table is still with us?
Just found this thread today.

[JXO]

Sorry for the delay but i have been taking this seriously. The motor required a custom pulley which should be close to ready. It may all be coming together in the next week or two. I enlisted some celebrity help with this project. Hope to have some results soon.