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andyz
02-08-2005, 04:50 AM
I have a 3 spindle drill press on a large table. I can mount a cross slide table on this underneath on of these spindles. Can I do milling on one of these spindles. I'm just looking to mill slots and other small things. I'm assuming I would have to run slow speeds and slow feed rates. Any thoughts?Thanks

DougR
02-08-2005, 05:24 AM
All you can do is try it. Drill press spindles generally don't have bearing setups suitable for the side forces of milling, but some of the heavier presses are capable of light milling.

Another issue is how to hold the cutter. Drill chucks are not the best way, but again your experience will show whether yours will do the job.

Doug

Kerry Pinkerton
02-08-2005, 05:26 AM
The bearings in drill presses aren't designed for side loads and will ultimately give you problems. The multiple splindle rigs I've seen are MUCH MUCH stouter than your garden variety drill press so they may hold up longer.

Hemirambler
02-08-2005, 05:28 AM
Andyz,
The drill press will work in a pinch for aluminum and soft metals - with EXTREME patience you might even get satifactory results in steel - iffy at best.

The problem is that drill presses are intended for axial loads not the radial loads you encounter in milling. Bottom line - the taper (assuming you've got a #2 or #3 morse) often loosens up creating havoc.

Proceed at your own risk :(

P.S. I've tried it - the results were underwhelming at best in steel - and moderately sucessful in aluminum.

Your mileage may vary.

Good Luck


Jacin in Ohio

GTmike400
02-08-2005, 05:28 AM
All you can do is try. But dont be upset when it doesnt work too well. I tried the same thing, didnt work at all.

ralph
02-08-2005, 06:52 AM
Andy,

Like the others, I've tried this a time or two. Results were poor. More importantly, the side load loosened the taper mounted chuck and I ended up dancing with it. After a couple dances I figured my luck was running out. :?

Now I have used it as a lathe, with a bit in the vise. That bordered on OK in a pinch.

rsanter
02-08-2005, 12:58 PM
I have been very sucessfull milling wood in the drillpress. metal was iffy but I have got it done in a pinch.

bob

benchracer1
03-25-2005, 07:42 PM
I bent the spindle in my craftsman 17 in press with a 1/2 mill bit.

toolmanMike
03-26-2005, 07:23 AM
Andy,

It sounds like you might have an Allen drill press.

To improve your success rate...use short end mills...make your cuts shallow...and your feed rates very slow. You may find higher spindles speeds don't cause problems but start out at low speeds.

Pay attention to whether your end mill wants to pull into the cut or push away from the cut. You want it to push away.

Avoid extending the spindle as much as possible by shimming up your vise. Always lock the spindle.

Drill presses matching your description are likely to have adjustable bearing clearance for the bearing at the bottom of the spindle. If it does try to take out all the radial slack and then tighten it just a little more to preload the bearing.

When I do experiments like this, stuff has a tendancy to fly all over the garage. I wear a full face shield. The last OSHA approved face shield I bought was $15...cheap.

Mike

bobadame
03-26-2005, 08:36 AM
There's a technique that will help. To mill a slot instead of milling straight through the work, try milling down in the Z axis. Do this in steps that involve only about 25% of the cutter face. The end of a mill has a more efficient cutting geometry than the side flutes. Do this with a smaller cutter than your eventual slot size. Then change end mill to the actual slot size you need and finish out the slot straight across. Also keep the spindle length as short as possible. You could even make an arm with a support bushing around the spindle similar to an over arm support on a horizontal mill. This would give the lateral support you really need to do this. Good luck

Bob

toolmanMike
03-26-2005, 02:20 PM
Bob,

The support is a good idea. It's also not unusual to pilot the tool with a drill bushing as part of a fixture. I would suggest fabricating a fixture that would straddle the add-on cross-feed that fastens directly to the table top.

Mike