Quick RPM question

Re: Quick RPM question

John Lucas

>I rarely use my lathe at 2000 much less over that. When production spindle turning I use fast speeds but the only difference the fast speed makes is to cut faster. If you slow down the speed that you move the tool you still get the same cut. To demonstrate this in my demos I slow the lathe down to 100 rpm or so and make the same cut I did at high speed. The surface of the turning is identical unless I force the cut.

I wouldn't say this is 100 percent true but I've been turning for 10 years and up until recently didn't have a lathe that would go over 2000.

Re: Quick RPM question

Fog Tanner

>For most of the spindle work I do, 2000-2200 rpm is more than enough. For a lot of the pieces, I keep the speed around 1500 rpm. Pieces of wood coming out the chuck over 1500 rpm tend to disrupt the organization of the human body in a not so pleasant manner. I found that the small reduction in time wasn't worth the risk, once dead center in the face shield and once on the wrist. Both during back hollowing above 1500 rpm.

My exception to this is pens and light pulls. I will run the lathe at 2700-3000 just to keep the surface speed up, mainly for friction polishing. But, since the wood is on a mandrel, I'm not concerned about it comming off.

If you are just doing bowls, 2000 rpm is way more than enough. The larger bowls would only need half or less than that. There are a lot of factors, like the size, the wood and how sound it is, the sharpness of the tools and the turner's skill level. Look at all the bowls that were turned on a pole lathe at less than 200 rpm......

Re: Quick RPM question

Wanna turn

>Hmmm...so if I want to do pens, pretty much I need the higher speed? Or only if I want to do a certain type of finish? Or can the friction polish be done even w/o the higher speed?

Re: Quick RPM question

Wanna turn

>Hmmm...so if I want to do pens, pretty much I need the higher speed? Or only if I want to do a certain type of finish? Or can the friction polish be done even w/o the higher speed?

Re: Quick RPM question

Fog Tanner

>You can do pens at a slower speed, you just have to slow the cut down to get the same finish. I only use a skew in doing pens, so I don't have to sand that much. The friction polish I use is the Shellawax cream, which is made for bowls. The key is getting the heat. The high rpms will generate the heat a lot quicker than the lower rpm, but you can still do it.

Also, I'm used to having my hand very close to a propeller on a model airplane engine turning at 24,000rpm, so 3000 rpm on a pen blank is still slow. Just a matter of personal preference. But, if you're turning at those speeds and you find you are turning with the cut or behind it and not ahead of it - that's the time to turn the machine off and go back in the house.....

Fog