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Lathe speed for drilling blanks

Phil Dart

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You can drill a lot of woods wood quite fast, but the denser the wood the slower the speed needs to be. Heat build up is your enemy, as is not withdrawing the bit and cleaning the flutes frequently. Acrylics need to be fairly slow otherwise there is a danger they will melt and fuse to the bit.

I drill everything on a pillar drill, and I tend to keep the same speed setting for everything, which is about 250rpm. Others will think that is quite slow, but I've never had a problem, and for the sake of a few seconds extra time, I'd rather be safe that sorry.
 

martin.pearson

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I dont drill a lot of blanks as I don't make that many pens but pretty much what Phil as said works for me.

Heat build up is your enemy, as is not withdrawing the bit and cleaning the flutes frequently Those 2 things are actually linked, the cut chips carry the heat away with them so on a retract your not just clearing the flutes but removing the heat. More important with acrylic as acrylic chips will re-weld theselves to the blank as well as clog up the flutes lol.
If your bit is to hot to touch once you have drilled a hole then you either have the speed to high or your not feeding the drill bit through the material quickly enough.
 

flexi

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I have been very fortunate on a press and not had tooooo many issues.....sharp bits....clean regular....and keep the speed constant Inc feed rate.....never force a dull bit....it will only end in tears:sob::sob:
 

Dalboy

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The normal thing with drill speeds are the smaller the bit the faster you need the speed, But having stated that with acrylics you need a slow speed as heat build-up will start to soften the material and pick up making the hole drill over size which is not needed especially when making thinnner style pens. And as alreaddy stated wood also needs to be drilled slow but not as slow as you would for acrylics.
The other factor is to withdraw the bit often to clean swarf as build-up can also cause overheating.

Always withdraw often as it avoids accidents:whistling::whistling::whistling:
 

21William

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One option is not to drill to the finished size in one go? Try starting with a smaller drill then go up. There must be an ideal grind for drilling acrylic but I don’t know what it is.

Edit: I remember now, modify the bit as you do for drilling brass. Google if you don’t know how, it’s not difficult.
 

Frederick

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As Derek said. The smaller the bit, generally the faster you may bore but that doesnt mean you have to drill flat out. I drill on a lathe at a speed of roughly 400rpm irrestive of what the material or bit size. Never had any problems to date. Always use sharp bits and never force them.
What you must be mindful and careful of, especially with plastics, is heat. Clear the flutes frequently. Clogged flutes bind and cause heat build up.

My maxim is slowly slowly catchee monkey. Common sense is the master here. I am no expert; this is just what I have experienced.

Cheers
Frederick
 
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