VPI Classic motor question

That's good info, Andy. Thank you. Yes, I do recall our exchange regarding the lubrication of the Classic motor. I advised not to disassemble the pulley and to use a syringe to put the oil in the space between the pulley and the brass plate. Having dealt with the current problem, it appears to me I was right on one issue, and probably wrong on the other due to VPI's awfully unclear instructions regarding the lubrication.

Beginning with what I think I was wrong about, VPI's instructions simply state to put a drop of 40 Weight motor oil "below the brass piece." No mention of removing the pulley or shaft adjustment. Considering that the brass collar is not visible without first removing the pulley, and you need to loosen up the screw in the "brass piece" to apply the oil, this is just unacceptably inadequate. The fact that the manual warns "not to disturb [the pulley] at all" in another section makes the lubrication instructions even more confusing. Then you have a brass plate around the pulley so to me it seemed it was the way to go. I wonder now whether putting oil around the pulley rather than at the shaft contributed to the noise problem.

Now, what I think I was at least partly right about. The screws on the pulley must be perfectly tensioned as the pulley will otherwise wobble/vibrate. VPI uses special tools to balance them; I had a lot of difficulty getting the screws perfectly balanced with a standard Allen key. The manual does not explain it, VPI in their email responses never mentioned it. I wonder how many Classic owners who removed the pulley to lubricate the motor now have vibrating pulley, which is either easily noticeable or barely noticeable depending how well balanced the screws are. So my advice still stands: do not disturb the pulley unless you want to spend a lot of frustrating time adjusting the screws afterward.

Andy, btw, do you use the SDS with the new motor, which you used with the 600 rpm motor? I want to upgrade the motor, but need to know whether I'll be able to continue using my SDS. Thanks.

I upgraded the motor on my Classic 1 to the 300 rpm ver and still used my SDS.

M~

Thanks Macster. I appreciate your response.

See below, my correspondence with Mike from VPI on the re-installation of the brass collar after lubricating the motor.
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Mike,
I have a Classic 3 for over a year with the 300 RPM motor. I took the Pulley and brass collar off and lubricated the motor. What is the prescribed method for re-assembly of the brass collar on the motor shaft?

1. The motor shaft has about 2 mm of play, up and down, should the motor shaft be down when inserting and tightening the brass collar? midway? or up?
2. Should the recessed part of the brass collar touch the fixed part of the upper motor assembly?

I tried a number of positions for the collar. If the collar actually touches the stationary area, and you put your ear up close, you will hear the collar rubbing against the stationary area. When the collar is just barely not touching the stationary area, there is not a sound. Therefore I concluded the correct position of the shaft at rest is at its lowest point, and the correct position of the collar is barely not touching the stationary portion of the motor assembly. So the motor shaft is at its resting point, you put the collar on, and position it so it is barely not touching the stationary area. Turn the motor on and listen. If you hear it hitting the stationary area, you have it too low. Try again. Try and get it so it barely doesn’t touch. Then tighten the allen screw. Is this correct?

*********Answer from Mike at VPI

Close!

When installing the brass collar you lift the motor shaft up, drop the collar on, lightly tighten the set screw. Turn the shaft, if it rotates easily (forget the thumps from the coils and magnets) and you have very little vertical motion of the shaft you are good. You should have very little vertical play but still turn freely. Snug up the set screw.

Mike

It was $150.00 plus the shipping, and I got the new pulley. I never had any problem with removing and installing either pulley. I just loosen the screws, removed the pulley, did what ever it was that I had to do and put it back on and tighten it "snug."

M~