Hi, I have a delta 14" variable speed lathe. There is a certain range
of speed (about 1/3 of the total range) where the lathe starts to
vibrate and wobble out of control, and it seems to be getting worse.
Please, if anyone knows whats going on, let me know. Thanks

wrote: Hi, I have a delta 14" variable speed lathe.
There is a certain range of speed (about 1/3 of the total range) where the
lathe starts to vibrate and wobble out of control, and it seems to be
getting worse. (clip)
^^^^^^^^^^^^^^^^^
Certainly you would not ask this question if the vibration were coming from
an out-of-balance piece of wood. It happens even when there is nothing
attached to the spindle, right?

Take off the belt and run the motor. Probably not caused by the motor, but
best to check things in order. Inspect the belt--is it about to break?
Check for anything loose in the spindle/headstock stuff. That's all there
is.

On Tue, 05 Jun 2007 12:55:42 -0700, wrote:

Hi, I have a delta 14" variable speed lathe. There is a certain range
of speed (about 1/3 of the total range) where the lathe starts to
vibrate and wobble out of control, and it seems to be getting worse.
Please, if anyone knows whats going on, let me know. Thanks

Everything has a natural frequency of vibration (cars, washing
machines, bridges, even trees). If you match the frequency, or a
multiple of it, to the object, it will vibrate. A variable speed
motor is very helpful here because you can tweak the speed a little so
it won't vibrate so much. Add a lower shelf to your lathe and put
some sand bags on it. Add the extra weight will change the natural
frequency of your lathe, plus absorb some of the vibrations.

A couple possibilities to look at:
1. The belt gets loose at certain speeds with a Reeves drive. You may see
it "bellying" out.
2. Also, the sliding pulley can wear on that lathe. Then that injects
vibration. Having the bearings at 4" apart or less with the pulleys hanging
way out (relative to the bearing c-c length) magnifies any drive issues.

You can also find that the vibration is caused by taking too big a
'bite' of the wood. I have a Vicmarc 100 which is a fantastic lathe
but I still get the vibration from time to time. I then realised that
it was me taking too thick a cut and now I use the vibration to tell
me that it's time to take a finer cut.

Kindest regards

Paul

On Tue, 05 Jun 2007 12:55:42 -0700, wrote:

Hi, I have a delta 14" variable speed lathe. There is a certain range
of speed (about 1/3 of the total range) where the lathe starts to
vibrate and wobble out of control, and it seems to be getting worse.
Please, if anyone knows whats going on, let me know. Thanks