General Category > General Discussion

Turning speed

(1/3) > >>

V8-108:
As a newbie to the hobby, I was laid in the bath thinking about the effect of turning speed on various things. I think I can probably guess the answer, but, what effect does turning speed have on end grain tear out in particular. Are you better at a slightly lower speed to give the chisel a "chance to cut", or will a higher speed "aid" the cut? I appreciate that a turners technique and the suitability of the chisel and it's sharpness are important, but when those things are equal, what effect does speed of turning have - if any?

BrianH:
It is true to say that the higher the surface speed the easier it is to get an acceptable finish...BUT... it is also true that kinetic energy rises as a square of that speed (I think). This means that the price you pay for the ease of finish is the very real possibility of a tiny error putting you, and your project, at a much increased risk of injury or destruction.
I gave this matter a great deal of thought, some years ago, and made the decision that I would work at the SLOWEST speed at which I could obtain an acceptable finish. It took a lot of practice but my skills soon increased to fill the void I had chosen to live with. It is perfectly normal to me now to work at a speed others find surprising. I actually feel uncomfortable on the occasion that a problematic piece calls for me to increase speed.
There are an awful lot of woodyfolk out there who rattle on about safety... or lack of it.... without considering the most obvious way to reduce risk is to reduce lathe speed.
Im sorry I cant give you a straighter, yes or no, answer. There is no right or wrong only a personal choice between risk and reward.
All the best with whatever path you choose
Brian

bodrighywood:
Speed (IMHO) is governed more by the nature of the wood, balance of it on the lathe etc than the need to get a decent cut. As Brian intimates, the best answer to the question is to start slow and build up to a sensible, safe speed.Turning an off centre lump of burr or a winged bowl will require different speeds to say a pen. for example.
Again we are back on the use of that  often missing factor 'common sense ' LOL

Pete

Bill21:
I’m with Brian on this one. I don’t run the lathe any faster than I need to. The faster the lathe is running the quicker accidents unfold and the farther the pieces fly!

If it’s tiny spindle stuff though that’s when the speed control gets tweeked.  ;)

BrianH:
Im thinking that bath water might be getting a little chilly by now but, before you reach for the pink and fluffy, here's another aspect of turning speed for you to consider.
To the lathe operator, and every writer in Christendom, the revs per minute are the important consideration and certainly the most quoted. At the coal face, however, Mr Cutting Edge has no interest or understanding of that figure. He's only interested in the velocity of next passing splinter. The surface speed!
At any given RPM the rim of a platter blank (say) has a lot further to travel than the middle and so it's surface speed is much higher (in fact, Im thinking that the very centre of the blank must have a surface speed of zero! how can that be?). So in an ideal world the Woodyturner ought to increase the RPM as he works toward the centre of his blank but, until a voice-recognition lathe comes onto the market, he will need to be permanently seeking the best compromise available. Yet another area where there is no black and white solution and practice and experience comes to the fore.     
Byeeeeee....Dont forget to clean the tide mark off the bath.......
Brian

Navigation

[0] Message Index

[#] Next page