Powermatic 90 questions

[leeko]

Hi all,
So, my PM90 clean-up / tear-down is now underway, albeit slowly. When I bought it, I was aware that it made a little more noise and vibration than is ideal. Over the last couple of weekends, I hooked up and mounted the VFD and control box. Finally got everything working last night. Now, it's time to figure out the source of the noise :)

I took the belt cover off, and removed the v-belt. It's a wider one than I'm used to - anyone know the size or type of this for replacements? Or, can I use a regular 1/2" red link belt in it's place?

Once I had the belt off, I played with the reeves drive sheaves. On the spindle pulley, the movable portion of the sheave (sheaf?) has about 0.5-1cm of play around the circumference of the spindle - I can rotate it a small amount by hand with the spindle fixed. Doing so recreates the same "clunking" sound I get when the lathe is running.
Is this small amount of play normal, or would it potentially account for the clunking/vibration I'm getting? Any idea how to fix it? I'm guessing I need to take the headstock cover off, and there'll be a setscrew to tighten or similar, but haven't yet figured out what to unbolt to get access to it :)

I know that spindle bearing replacements are also in my imminent future, but I'll need to save my pennies before I can make that happen. I'm not sure the bearings are the source of the problem, though - spinning the spindle manually with the belt removed is smooth and silent.

Are there other bearings in the headstock that will likely need replaced? I've read something about v/s roller and v/s roller bearings, but I'm not sure exactly what they are or whether to tell if they need replaced.

Thanks in advance, sorry for the multiple questions,

Lee

[vk4]

Leeko,

could you post some pictures , of the machine and what you have done so far.

I do not think that there should be any movement in the SHEEVES(Pulley), and think this should be investigated first,..

If the shaft runs smoothly and has no side or end play , leave it alone, just to check , borrow an engineers dial gauge and stand and measure any throw/end play in the shaft,

If the belt is worn , replace with a belt of the same type, link belts, may not cut the grass.

Hope this helps

Jeff
vk4

[leeko]

Hi,

Here are a few pics of what I'm seeing. Having played with it a bit more, I believe the play is in the outboard-side bearing - I don't see any set screw or similar for the inner reeves sheave (at least not outside the headstock) The pictures show the amount of play (in a clock-face orientation - there's no fore-aft or up/down/side play at all).

With the spindle locked, it's possible to move the sheave (with the blue tape attached) about 2-3 degrees. Not sure how much of a problem it is, but wondering whether it's the source of the vibration.

There's also some fore-aft play in the motor arbor - maybe 5mm or so. With the belt off, and the motor running, there's a very small amount of vibration - just detectable that the machine's running. With the belt on and the spindle turning, the vibration level goes up by a lot.

Is there any way to get inside the headstock? The user manual shows an exploded headstock diagram but no instructions how to get inside. It seems like a solid piece of iron...

Also, is there any way to tell the model of the outboard-side bearing without taking the reeves mechanism off? I'd rather just tear this down once, with new bearings in hand, if at all possible!

Thanks again,

Lee