drill press rpm range for woodworking

[David Milstone]

What range of spindle rpm is sufficient for a flexible woodworking drill press? I've seen the range of 250-3000 rpm recommended to cover 1/16 - 1 inch twist and brad point bits in hardwood and softwood. Is this reasonable? I'm looking at a 5 speed (via belt changes) press that runs 400-3,000 rpm.

I trust this seemingly simple question could lead to expansive discussion of the requirements for special applications. However, I am interested in a general consensus on the minimal range necessary to handle "middle of the road tasks", using a range of bits but not necessarily extreme sizes (large), in both hard and soft wood.

Thanks.

[Pete Bradley]

This topic has been discussed pretty heavily here. You might wade through this discussion:

http://sawmillcreek.org/showthread.php?t=99512&highlight=press

[David Milstone]

Thanks very much. I searched but found several hundred posts, meaning it has been discussed but my multiple key words didn't help reduce it to a manageable task. I will look at the link you provided before going further.

Dave

[Mark Sodja]

I have a 16-1/2" Jet drill press with 16 speeds. I find that I use the slower speeds more than the high end. The slowest speed on my press is 200 rpm. I use it regularly for large Forstner bits and the occasions when I need to use an adjustable circle cutter. I would say that my press is run at 2000 rpm or less 90% of the time.

-UtahAV
-Mark

[Steve Schlumpf]

David - I downloaded a chart a long time ago that gave suggested speeds as per drill bit (type, size, etc) used. I believe the chart I downloaded was from Wood magazine. It may be worth checking out: http://www.woodmagazine.com/woodworking-tips/techniques/drilling-boring/drill-press-speed-chart/

[David Milstone]

I've read the posts and there is much info. Thanks to all. Is it reasonable to consider adding a larger motor-side pulley to reach lower rpm? I guess belt length/tension dictates a correspondingly smaller quill-side pulley, right? Might get awkward. I've seen "slow speed attachments" for some older dps. Are these reasonable? Seems many older dps on the used market don't reach the lower rpm recommended for many woodworking bits, like below 400 rpm. How "bad" is it to run a 250 (or lower) rpm bit at 400?

Dave

[Pete Bradley]

Is it reasonable to consider adding a larger motor-side pulley to reach lower rpm?
You'd need a smaller motor-size pulley to reach a lower RPM. This might be doable as long as the belt will still clear the column. I'd go with an AX belt both for the smaller diameter and for the reduced tendency to take a set.


Seems many older dps on the used market don't reach the lower rpm recommended for many woodworking bits, like below 400 rpm. How "bad" is it to run a 250 (or lower) rpm bit at 400?

Compare three manufacturers' charts, you're likely to find they're all different on what's "optimal", particularly for Forstners. Slower isn't always better as if you go too low they pack with chips rather than ejecting them.

The lowest speed on my 1960 Delta "Slo Speed" is 450 RPM, and that's never been a problem.

[David Milstone]

You'd need a smaller motor-size pulley to reach a lower RPM.

Woops. You're right. Thanks.

[glenn bradley]

My low end is 250; wish it were lower.