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Tim McClelland
01-02-2011, 3:02 PM
Hi and Happy New Year to all you Creekers. I have a basic question to do with hollowing. For my birthday my wife gave me a set of hollowing tools (from PSI). Before I attempt anything I was wondering what speed is normally used for hollowing. When I make pens or other small objects I usually run around 1800rpm but was wondering if I need to slow down to do some hollowing. Your knowledge and experience is much appreciated. Thanks in advance.

Jim Burr
01-02-2011, 3:04 PM
SLOW!!!! I turn pens at 3000, just what I prefer. HF's I do at 500 because that's as slow as my 1014 will go!

Brian Ashton
01-02-2011, 4:03 PM
Every piece will have a different speed that is "optimum". Factors include: diameter, length, species of wood, density... The best thing I can suggest is play with the speeds. For years I did what I had read about and that was to find the fastest stable rpm... But in later years I've found that I like turning the rpms down way below the those norms and have found the results are more to my liking in that I have better control overall. You have to adjust how you approach a turning in that you need to be careful of taking too deep a cut as it can be easy to "push" an over sharp scraper in too fast.... The catches are less catastrophic but can be more frequent until you get the hang of it. I find a slightly used edge better at slower rpms. My favourite hook tool for such work I made years ago that has carbide tip brazed on it. It looses it's razor sharp edge almost immediately but maintains a usable edge almost indefinitely. I use to hog out 200 cubic inch oak urns with it and didn't have to sharpen it very often.

Wally Dickerman
01-02-2011, 5:37 PM
There isn't a "standard" speed for any part of woodturning. John Jordan has said that he hollows at around 800 rpm. I watched, somewhat fascinated, as Cindy Drodzda turned a 4 in. dia. off center hollowform at 3000 rpm.

In my own turning, I usually hollow at somewhere between 1200 and 2000 rpm. Depends on the condition of the wood. Of course the size of the piece is also a factor. Turning at slow speeds drives me nuts. I find that wood cuts smoother and with fewer problems at higher speeds.

Until an inexperienced turner feels comfortable with the hollowing tool it's a good idea to start out slow. 800 to 1200 rpm is my suggestion. Then, as you gain experience, crank it up to a speed that feels right.

Wally

Bernie Weishapl
01-02-2011, 7:01 PM
I hollowing from 800 rpm and 1200 rpm. It takes a while to get comfortable there but it sure does make hollowing easier.

Steve Schlumpf
01-02-2011, 7:18 PM
Tim - I've been hollowing for a few years now but compared to Wally - I am a rank amateur! I do have a couple of hollowing systems that I use (captured and articulated) and they really make a heck of a difference when hollowing - but normally I hollow between 850 and 1250 rpm - depending on the wood. Some wood - very off balanced - hollows OK at 800 rpm but I do find that the more I do - the more I like the higher speeds. So far the highest speed I have ever hollowed at was 1450 rpm. I was very aware of the speed - almost uncomfortable - but pushed myself to give it a try. What I found was that you do get cleaner cuts at higher speeds but you have to stop and remove the shavings ever couple of seconds! Sure gets old after a while but that it the nature of the beast when it comes to hollowing!

Find a speed that feels comfortable to you - and stay there until you find it time to increase the rpm. You can always change what you are doing according to the input from others - but - the key thing to remember is to do that which feels comfortable to you! Most importantly - just relax and have fun!

Brian Libby
01-02-2011, 7:34 PM
I agree with Steve! Several nationally known turners have stated while demonstrating - " Turn at a speed you are comfortable with ". great advice - there is no magic speed

Peter Fabricius
01-03-2011, 2:52 PM
I certainly agree with the advice about a comfortable hollowing speed. It can get scary if you get outside your comfort zone. If your lathe is limited in slow speed, take very light cuts and find your zone.
Does anyone use a vacume tube in the hollow form to get rid of the stopping and clearing chips like Steve mentioned?
Peter F.

Steve Schlumpf
01-03-2011, 2:58 PM
Does anyone use a vacume tube in the hollow form to get rid of the stopping and clearing chips like Steve mentioned?
Peter F.

I use my shop vac... does that count?

Bob Haverstock
01-03-2011, 9:09 PM
Well Gee,

Most of the hollowing that I do includes using a steadyrest. So for me the question is how fast do I want to turn my steadyrest wheels. Most of my "hollows" are 4 to 8 inches in diameter and are roughed into "green" wood. Freshly hollowed green wood certainly lacks a fine finish. I guess all I can say is " Work within your comfort zone."

Bob Haverstock