Spindle turning Speed

I found this on another discussion board - it's from someone that knows what they're talking about (Lyn Mangiameli):

"With respect to safety, determine your speed based on the maximum diameter of your turning. A good rule of thumb is the one (to my knowledge) first established by Dale Nish: Diameter times RPM should equal 6000-9000 rpm (D x RPM = 6000-9000 RPM). For example, a 20 inch bowl turned at 400 rpm is going to give a figure of 8000, while a 10 inch bowl turned at 800 rpm will give the same figure. Generally I'd suggest you shoot for something closer to the lower 6000 rpm figure. Put another way, don't seek to always go the speed limit, but instead shoot for something closer to 80% of your speed limit, this gives you some margin for error."

So, in your case, you can probably safely turn from 3,000-4,500 RPM. This is likely the maximum range of most lathes (but, this is coming from a newbie, so I could/likely be wrong). You probably know that it is typical to rough turn slower and then increase speed to give a smoother finish as your diameters decrease (or at least that's the way I think about it).

Hope this helps,

Mike

As slowly as possible for your safety. ~500

You need enough angular velocity to overcome cutting pressure, which is seldom significant, or scraping pressure, which can be considerable. Increase speed if the thinner piece tries to squirm away from the tool up to perhaps 1500. Remember that you now have nine times the energy you had at

Mike and George..... Thank you for your advice...... Now I just have to decide..... somewhere between 500 and 4500...... LOL! I understand Georges concern for safety and I also understand Mike's comments based on info from established turners also... hmmmmmmm

========================= Buck, Roughing should be at lower speeds than maximum allowable. During roughing, you are not in constant contact with the work piece through out its entire rotation, so it's easier to dig in. In other words, square stock should be slower than round stock. I'd start 2 inch square between 500-1000 RPM depending on wood species, wet or dry, etc. I seldom go above 2000 RPM.

Ken Moon Webberville, TX

Ken.... thanks for the advice. I guess everybody is pretty much right. I will take your advice.

That's it. Let _your_ experience and need determine what you do.

Ever watch Ol' Roy Underhill work on his lathe? Don't take much speed to cut wood right.

..... You ever see Roy Underhill's fingers??? LOL

When you lead with your knuckles in sawing, planing and carving, it's unavoidable. Plus, he persists in using that inappropriate T-handle bludgeon as a mallet to the detriment of his nails. Seems he could work up a good carver's mallet on the lathe.

Bottom line on speed is that what seems too fast to you - is. Of course, what I said first still applies - much more energy available at faster speeds. You decide if that's friend or foe.

I've been doing this quite a bit lately turning LOTS of kitchen utensils out of Brazillian cherry, Walnut and Maple. I usually start with flat blanks about an inch think by 2 inches wide by 12-14 inches long. I do not change the speed of the lathe when starting to when I'm finished and it's running at 1800-2000 RPM. Now I agree, you need to be VERY careful. There's a lot of wind there meaning no wood. When I start the turning the roughing gouge is barely touching the wood and I slowly chip away during the first passes. I always start in the middle and work out and as the piece comes closer to round I can make the cuts more aggressive but never TOO aggressive.

I agree, start slow and as your comfort level increases so can the speed. I recently started my 12 yr old on turning and started him off VERY slow so he could understand exactly how the tools cut and how dangerous a flying chunk of wood can be. He has great respect for it now, so I've increased his speed a bit but not too much, I think he's up to 750 now. It's a learning process and don't go too fast.

Hope this helps.

Mike Rinken

Mike - That helps a lot....Thanks You!

I probably run at about the same sort of speed for 2" maple, though I have VS and really don't know the absolute speed, preferring to run the lathe as fast as it can without vibration or making me feel nervous.

One reason for running the lathe fast is that the body can better dampen out the percussive effect of the corners of the blank slamming into the tool. That means better control of the tool, and therefore less chance of a dig in. I start with the tool off the wood, making the first approach with care to be sure of the depth of cut. I make a quick U-turn at the end of the each cut and go back and forth.

Out of interest I just went and roughed down a piece of hard maple, about 1 7/8" squarish and 11" long to a cylinder. I did this in 10 passes in about 20 seconds. If the lathe and VS settings are to believed, it is running at about 2100 rpm.

I'm saying all that for information only, and not to start a competition, or to encourage beginners to do something they are not comfortable with from a safety perspective! I have been turning full time for nearly 10 years and I am very comfortable with what I am doing and have absolutely no concerns about the wood coming off the lathe or the tool getting embedded in the ceiling. But I do think it is important that beginners understand what is possible.

I remember that when I first started bowl turning I was shown how to hollow the bowl by making nice curves parallel to the outside of the bowl. This was a great way to practise the art of making finishing cuts, but it is terribly slow. I have since found out that I can hog out the guts of a bowl much quicker by making straightish cuts nearly to parallel to the axis. I do this until I am close to the finished shape, then slow down to make the finishing cuts which refine the shape and achieve a good surface finish.

Derek... Thanks for taking time to help. Lots of good info here. I will definately re-read it a few more times. I also checked out your website and the work you do. Very nice indeed and recommend everyone take a look see....