Dumb Question: Is the (almost) new belt sourced from VPI?
If the belt isn't to VPI specs, it could affect speed.
If the belt isn't to VPI specs, it could affect speed.
Thanks gentleman. The belt came from Musicdirect with a receipt
that SAYS it's the correct belt, but I guess I cannot totally
rule that out as a mistake.
As far as motor positioning, I have moved it as far and
as close to the plinth as possible, with no results.
Again, thanks for your thoughts thus far!!!
Did you try putting the belt in a bag with some talcum powder? Shake it up a bit, put it on the pulley and table , then see. This may help slow it down.
Though I'm guessing the obvious answer, a VPI SDS, is out of the question?
I own a Scout, and I am not using an SDS, but I'm not having any speed issues either.
Is the 11.5 inch platter standard for the Scout? It sound like you have a motor pulley designed for VPI's 12 inch platter or the pulley is out of spec. You have a couple of options. Replace the out of spec pulley for a 11.5 platter pulley or upgrade the motor to a 300 rpm motor which comes with a new larger pulley. Don't forget to mention to vpi that you have the 11.5 inch platter.
For reference, with the 600 rpm motor, I was at the very top of the pulley to get 33.3. When I changed to the 300 rpm motor I got much better speed control.
The 600 rpm motor uses a pretty small pulley. The 300 rpm motor uses a significantly larger pulley. For reference, my 300 rpm pulley is 1 and 1/4 inches across the top. The 600 rpm pulley is significantly smaller. Do you have the right pulley? I believe there is also a different pulley for the 12" platter versus the 11.5" pulley.
When using the 300 rpm motor, a capacitor needs to be changed. Is it possible that the original owner changed the capacitor?
If possible, I would ask the original owner if they had made any changes to the motor, capacitor, pulley or platter.
It sounds like you may have the wrong pulley. I would ask VPI to send you the right pulley for your platter/motor. It may be that the setup has never been right.
You are not the first to have this problem. Rest assured, you will get it right.
Thanks DTC- my pulley is well under 1.25 inches at the top, more like .5 inches...i also believe you are correct, it would only make sense that there would be a slightly different sized pulley for the 11.5 inch platter vs the 12 inch platter for the 600 RPM motor.
I don't think the original owner made any mods that I am aware of, in fact, I think he's been running this thing fast for the three years he owned it...no wonder he went back to CDs.
Is the pulley swap pretty easy once I get it? I'm no mechanical engineer, but not a total dunce either.
Changing the pulley is trivial. There is a small hex set screw at the base of the pulley. You just need the right size, readily available at a hardware store if you do not have one. Take a look and you will see the set screw.
I remember a similar thread a while ago and the problem was a wrong size pulley. I would ask VPI to send you one for the 11.5 inch platter. I think that will fix the problem.
FYI - I found the 300 rpm motor a significant upgrade. With the 600 rpm, the belt keep slipping and the speed was variable. With the 300 rpm with the larger pulley, the speed really locked in. Not everyone agrees, but I found it a real improvement. You do need to change the pulley and the capacitor in the motor box, but it is a relatively easy change.
As mentioned above it sounds like you have a motor pulley for a 12 inch Platter
and are running it on a 11.5 inch Platter, it will give exactly the deviation you
The math is pretty simple, 12 / 11.5 x 33.333 = 34.78 rpm
The speed of the motor is determined by the number of poles in the motor
combined with the line frequency it attached to, it will only deviate if the line
frequency changes. Also a less than optimal drive system will only cause the
platter to run slower due to slip, it will never run faster only a higher line
frequency can cause that.
I bet its the motor. I also bet VPI doesnt call you back anytime soon. Sorry, guys, but I am a VPI owner and I just cant get an email back from those guys. I know they are only in on the days that the moon is alignied with Io, but still...
I did get an awesome upgrade by going from the motor you have to the upgraded one, and, for a grand, maybe the way to go-you should also add the SDS (another grand).
Thanks all for the replies, much appreciated. I did forward this thread to VPI and got a response from Ian, who had me send some pictures, but then the line of communication went silent again. Bummer. I may consider the upgrade to the 300 rpm motor at some point, seems pretty basic and not all that expensive. I'll try and keep you all posted if/when this gets resolved.
Got ahold of Matt at VPI today, and I just need to send out the 12" pulley and they will send one back for the 11.5" platter...any tips on how to take off the pulley? Is it a tiny little hex nut on the bottom of the pulley itself? The rest of the Scout uses a 5/64 hex, this one seems smaller? Thanks in advance!!!
Actually there should be three set screws at the bottom of the pulley. I just replaced my old 600 RPM motor with the 300 RPM motor, I had to, the old one was dying. Then I had to wait another 2 weeks for VPI to ship me out the new pulley that I would need with the 300 RPM motor. Both pulleys, on the old motor and new motor, have three set screws in the bottom of the pulley to hold it to the motor shaft.
Fairly simple swap. All you need is a 5/64 Allen wrench.
Thanks BRF- the original is on it's way to VPI, and I wouldn't mind them having it in their hand to make sure they don't send me the same pulley again by mistake. Unlikely, but so is putting a pulley for a 12" platter on my motor in the first place:)
Also, to save headaches for anyone attempting the pulley swap in the future, the grub screws on the pulley are 1/16, and the screw attaching the brass nut below is 1/20...why the hell the US never went metric I'll NEVER understand haha
Received a new pulley from Mat today, and speed is now dead on:)
Of course, now I come to you with another request for assistance...the motor now "clicks" fairly loudly (can be heard from 6 feet away)...it almost sounds like something is rubbing inside? This noise wasn't present AT ALL with the previous pulley, which I find odd...any ideas?
Fixed. In case anyone ever pulls apart the motor, it's really a simple beast. What happened was when I took off the brass nut that sits under the pulley, it allows the drive shaft to lower to the very bottom of the motor casing, creating a vibration. You have to manually hold up the drive shaft while you re-attach the set screw, and it holds the drive shaft a few mm above the bottom housing of the motor base.
So is the brass spacer under the pulley still off? I have the same clicking noise when the motor starts up with the new pulley. So you are saying I need to lift the motor shaft up and push the pulley down before tightening the pulley set screws? Should I take the brass spacer off? That sounds like a tricky operation, there's not much room in there.
The brass spacer is on, but the trick is (at least for me) was holding the brass spacer set screw in place with the Allen wrench WHILE you push down the pulley to meet the brass spacer. If you don't hold it in place while you push down the pulley itself, you are actually pushing down the drive shaft ever so slightly into the motor casing, causing the vibration you are hearing (I think). If you need me to clarify let me know:)