I finally got time to shoot some video of these drills working. They have been mounted for a few months and I have received a couple dozen emails about them. I will give an explanation of the hows and why's.

Let me first state that this is not neccessarily a way to save a few bucks versus buying the ShopBot Drill system for your PRS. At $1,700 retail new, plus a few hundred more for valving, wires, tubing and fittings, you could easily spend LOTS more than the PRS drill costs. (Especially if you buy a used one that needs rebuilding and revalving as I did) You may be able to find them used for a good price, but there are about a hundred rpm and valving options, so be careful. They are a very good solution for shops with smaller compressors and drill very clean holes, due to the adjustability. You can notice in the videos that the 8mm drill plunges much slower than the 5. This keep the hole quality very good.

Drills were mounted on shop built aluminum brackets to the OEM spindle plates.
A 1 1/4" Delrin mounting block was used to mount the drill to the brackets.
Prox and rare earth magnets were added so that full hole depth can be confirmed prior to gantry movement.
Both plunge and retract speeds are adjustable on the fly for varying material density.
Drills have RPM range from 500 to 17,000 rpm and HP from 1/6 to 1/2

Here is a pic of them mounted on my gantry:


38159.jpg

And here is a link to a video of them drilling: http://www.youtube.com/watch?v=fk_zWioyvQs

And another showing them working without the vacuum noise. This allows you to hear drill action and compressor use, as it actually starts up and then stops during drilling. http://www.youtube.com/watch?v=Tr5Tv...eature=channel

Gary