3520B Vibration?

[jason lambert]

I just got my 3520B assembled and set up. Wow what a nice lathe and a nice size. Really happy with it except with one issue. I get a vibration that starts around 500 rpm and is most pronounced around 700-1100 rpm's. I did take off the belt and the motor and berrings seem to run smooth but when I put the belt back on and enguage the headsotock with no attachments attached I get a vibration that can be felt and herd through out the whole machine? Switching speeds did not help.

How do I find out what is causeing it and could this be normal this is the first big lathe I have owned and I have never used a powermatic I have been using stubby's and oneways and all of them hove been smooth throught out the whole rpm range?

[Steve Schlumpf]

Jason - without knowing anything more about your setup - I have to ask if the lathe is level? That will cause all sorts of problems!

[Jack Mincey]

What Steve said, and change the tension on your belt. We have a 3520B at my school shop that I teach at and the tension can cause it to click some times. Change the tension and the click goes away. I don't know why this happens, but it isn't a big deal.
Jack

[Dennis Peacock]

Also check the belt....make sure it is very smooth and not bumps. Open the door and SLOWLY start the lathe and watch the belt for any odd "behaviour". If it looks good, then as Steve said? Check for level and all feet are making contact with the floor.

[Gary Herrmann]

Agree with Steve. Did you put a level on the ways to ensure it is level in all directions? Cast iron will flex - that could be the culprit.

When I assembled mine I had a bit of vibration just because I was impatient and wanted to turn the thing on. Then I went back and leveled it. No more vibration.

[Doug Thompson]

Jason, do all of the above and tighten the set screws on the pulleys inside the head... they will come loose.

[jason lambert]

Ok went and leveled it, still not sure how that could cause vibration in the head stock with nothing on it. But it is level. The belt looks good, when I loosen it (more than I like) the sound quiets and the vibration lessons but it is still vibrating the lathe and is still there.

This lathe has run all of 10 min just could be a slight flat spot in one of the berrings, I will let it run a hour or so and see if it works it's way out. just wanted to make sure I wasn't missing something stupid, as I said this is my first big lathe.

Thanks for the advice.

[tim mathis]

jason is the head locked down. when i first got mine everytime i moved the head, i would forget to lock it back down.now it is the first thing i do.

[jason lambert]

Per Dennis's advice (thanks Dennis) I did check the belt and noticed some nicks on the pully looks like someone grabbed it with a tool. Anyhow I took off the berrs and the vibration lessened but is still there, I am letting it run now and eating up AC in hopes it will break in. The motor cover also has a ding from where the wood came unlodged in shipping, didn't care about htat but with both issues. I supect I just got a bum unit it works but I will probably give the person I bought it from a call on monday to see if powermatic can swap out this head. It is just not right and bothers me. Anyone turning on it will also notice the vibrarion it it is pretty anoying.

Thank you everyone for the advice. This board is awesome.

[Scott Hubl]

First things first- Get on the Phone with Powermatic.

New lathe under warrenty CALL them, they will with you figure out if anything is wrong and Correct it if need be.

[Rasmus Petersen]

well i have some of the same thing. mine vibrates at around 700 also. i assembled it according to the plans, and put washers metween the legs and the bed. i took them out and it reduced the vibrating a lot!

[jason lambert]

For the people that have the vibration can you also hear it likt a tic, tic, tic... and feel it. It never seems to go away just speeding it up hides it. I can both feel it and hear it.

I didn't put any washers between the legs and body, was I suppser to? Guess I should of looked at the instructions more carefully, but I'm a guy instructions and driections are not my thing ask my wife (thank god for GPS).

[Dick Strauss]

Might the pulleys be out of alignment? It would probably happen on both speed ranges if they were machined correctly...

[Reed Gray]

Another thing could be that all 4 feet are not in full contact with the ground. Being level is one thing, but concrete floors are never dead flat, even mine, and I did concrete for 30 years. My 3520A model would vibrate some once in a while, and because the lathe was up on a couple 2 x 4s, I had to add some shims under one of the legs. That also got rid of some of the vibration.
robo hippy

[JerHall]

I had a high spot under the locking mechanism where the headstock meets the ways. I fixed it as discussed here:
http://docs.google.com/View?docid=d4b7vjd_15djv9mx#Head_Stock_Rocking
go down to heading "Head Stock Rocking"