Thread: Best speed for power sanding

Sometimes difficult grain responds to a change in direction Peter.

But you can switch to the other side of the pad to change direction.

That can cause difficulties though at a bowl rim where it's best to have the sanding pad running from wood to air to avoid dubbing over the edge if you don't want that.

Yeah, I agree with Ern. It ain't essential to sand in reverse and if you can't then don't worry. Sanding in reverse can unwind the chuck.

Peter
To get the maximum sanding effect , the cutting edge of the sanding disc needs to be rotating in the reverse direction to the lathe direction . This may vary depending on whether you are sanding on the near side or the far side of the bowl . You can live with this limitation it's just nice to have options .
Ted

Originally Posted by rsser

I had a look at air tools, in order to get the benefit of a 45* angle head drill. Only wrinkle is that this tool needs a lot of compressor capacity and so is big bikkies.

Yeah, often looked at those neat little air tool hand pieces myself, but the thought of a compressor pounding away constantly doesn't appeal.

Originally Posted by turnerted

To get the maximum sanding effect , the cutting edge of the sanding disc needs to be rotating in the reverse direction to the lathe direction .

If you run the lathe in reverse on alternate grits, then the ability to reverse the sander direction is essential to maintain the sanding action outlined by Ted . I don't bother reversing the direction of the lathe having never found it to make that much difference, but I do frequently reverse the direction of rotation on the sander to optimise the angle of approach to the multiple facets on a piece.

Contrary to most others, I run my sanding head at full speed (about 3000rpm) and my lathe at the same speed that I completed the the finishing cuts on the piece (eg about 1000 to 1500rpm on a 12" bowl). I don't find the abrasive getting noticeably hot.... not surprising given the fact that in every revolution the abrasive is spending the majority of the time spinning free in the air. But, I do use a light touch.

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I agree that it is a nice feature to have, although I can't run my lathe in reverse so it is not really necessary.

Spoke to my retired sparky mate yesterday and he said that it is possible to wire it up so I can change direction as he learned it in his first year of apprenticeship many years ago. He is going to look up his old notes and see if he can still do it.

There is also a book on small electric motors in my library that I have placed a reservation on that may guide us on how to do it.

This possible modification of the drill press is not really urgent as I'm only getting into power sanding, having only recently started turning bowls, meanwhile I can use a drill if needed.


Peter.

My setup, copied from Vern, is a flexible shaft powered by an ancient hand drill fixed in an ancient drill press stand no longer working, set on the lowest of the 2 only speeds. I do not worry about that speed because I can always vary the lathe's speed to find the best combination.

Re sanding in reverse. Last weekend I saw Tim Skilton demonstrate it by using the reverse switch on his lathe. He said that just by screwing on the chuck a bit harder with a final bump he never had problems with the chuck unscrewing. His reason for reversing was not so much for getting a better sanding, just to send the dust towards the chute instead of towards himself.

Given that I do not have a reverse swhich but the headstock can be swiveled around, can anybody see any problems with doing it like that, besides having the on/off swich at the back? Haven't tried yet.

Originally Posted by Frank&Earnest

M
Given that I do not have a reverse swhich but the headstock can be swiveled around, can anybody see any problems with doing it like that, besides having the on/off swich at the back? Haven't tried yet.

I can't see any problems except that access to the on/off switch is not easy in an emergency. I would wire in a kill switch located in a convenient position at the front of the lathe in the power circuit to the lathe.

I got a large architrave light switch from Bunnings for $ 10 for that purpose.


Peter.

Thanks Peter. A knee kill switch is a good idea regardless of the reversing, that may be the way to go. Which rises another question: at that point it might be worth installing a reverse switch also, which saves the trouble of swiveling the head but leaves the problem of the possibility of unscrewing the chuck. Tim and Brendan seem to value this option differently. Can we have a straw poll?

I like the controls on my current lathe which can be moved to any preferred location.... which is always within reach so I don't have to move into the firing line to hit the stop button.

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