View Full Version : Po' man's mag drill.

02-24-2017, 11:20 AM
Iíll soon be drilling & tapping a ton of holes for mounting the THK linear rails on my new CNC project. I donít have a mag drill so I came up with this rig to help out.

http://i57.photobucket.com/albums/g227/DBAviation/Drill%20Stand%202_zps00rp58dk.jpg (http://s57.photobucket.com/user/DBAviation/media/Drill%20Stand%202_zps00rp58dk.jpg.html)

A friend let me borrow his lever-assist safe drilling gizmo but it wasnít designed to keep the drill truly vertical. I was afraid the drill would move in an arc so I made up a guide stand by modifying an old British Leyland screw press I had squirreled away with some longer rods and 2 acetal bushed aluminum plates to attach to the drill. He also let me have a 12V electromagnetic security door lock. I ordered another one from ebay for a total of (allegedly) 1200 lbs. clamping force. The E/Mís wonít be used to anchor the end of the lever, just to solidly clamp the base once the hole position is located. A chain either wrapped around or bolted to the table at the far end of the lever allows applying as much pressure on the drill as needed. The length of lever is adjustable out to about 3 feet.

http://i57.photobucket.com/albums/g227/DBAviation/Drill%20Stand_zpsql9v6u4o.jpg (http://s57.photobucket.com/user/DBAviation/media/Drill%20Stand_zpsql9v6u4o.jpg.html)

Hereís a pic of the parts. The drill spindle was buggered a bit from slippage so I milled 3 flats on it to stop that problem

http://i57.photobucket.com/albums/g227/DBAviation/Drill%20Stand%20Parts_zpsrj7woehf.jpg (http://s57.photobucket.com/user/DBAviation/media/Drill%20Stand%20Parts_zpsrj7woehf.jpg.html)

Hereís a pic of the wacky setup I used to mill the flats. Finally found a use for the clamped V-blocks I picked up a long time ago.

http://i57.photobucket.com/albums/g227/DBAviation/Drill%20Stand%20Chuck_zpszh5exwbj.jpg (http://s57.photobucket.com/user/DBAviation/media/Drill%20Stand%20Chuck_zpszh5exwbj.jpg.html)

Iíll post up some pics of the completed electromagnet lash-up and a report on how it works this weekend. I figured on wiring the E/Mís in series & use one of the 24V linear power supplies I have and put it & a switch in a little electrical equip box.

Black Forest
02-24-2017, 11:34 AM
Very good. Can't wait to see a video of it in action!

02-24-2017, 11:41 AM
That would be the perfect tool for chain drilling holes...... BADDA-Boomp-CHING! :D Thank you, thank you. I'll be here all week.....

That's quite the Rube Goldberg setup. But very clever at the same time.

02-24-2017, 11:47 AM
That's quite the Rube Goldberg setup.Hey, I resemble that remark. (...and proud of it too.:D )

02-24-2017, 01:31 PM
Anyone can buy a mag drill (if they have the cash of course) but making one from various bits and pieces takes some real skill. Kudos!

02-25-2017, 09:17 AM
Nice solution. That has the advantage of also working on aluminum.

I watch for mag drills in auctions and the milwaukees seem to command a consistent price. So you could buy one for a couple hundred and then sell it after your project is completed. Of cource you want to make sure the chuck is good, the magnet works, etc. And probably that it hasn't been dropped. Old black and decker units apparently aren't nearly as good because they tend to go cheaper.

I was recently wondering about making one, as many have wondered before me. There have been tremendous advances in magnets in recent years. What would it take to make a switchable mag base, with surplus magnets? Not a lever switch, where it is pried from the surface, but one where it switches the magnet off.

I figure if you can work out the mag base, then the rest is fairly simple and could evolve over time. The upper portion could evolve over time. Drip lube, power feed and a laser indicator would be slick.

I popped over to see what I could learn from Milwaukee about the strength of the magnet basic, etc. The latest units are cordless, at least some of them. They have non-electric switched magnets. That way the mag drill doesn't fall if power is lost. Apparently power loss is awkward when you're on a ladder, drilling over your head. With the new motors and magnets and lithium, these new units are "ligher", 30 lbs. $2200 at h-depot, not sure if they are sitting on shelves for inspection.

Back to the magnets, I'm not sure what it takes to make an efficient magnetic rotor. I'd guess small commodity rare earth magnets could be grouped togther in a fixture and potted in epoxy. Or maybe finding a deal on a surplus larger magnet is the way to go, but I think that might be more difficult to switch on and off, since the form factor would be fixed. I'd hope someone else has already worked out the details on how to do that, maybe as part of a university project.

The milwaukee holding force is "up to 2,000 lbs".

Seems like putting together a modern DIY design would be a great home shop project.

02-25-2017, 09:42 AM
Ironically (:rolleyes:) last night my neighbor/friend/customer dropped off the latest pile of broken stuff to fix over the weekend before the plant opens back up on Monday.

I was figuring out how I'd mount the E/M's when he walked in. He takes one look at the drill stand & says "That's pretty cool but I've got the real-deal Milwaukee at work gathering dust in my closet. We bought it for one job years ago & haven't used it since. Text me on Monday & I'll bring it home for you to use as long as you need it.":eek: Can you believe that!

Oh well, as I often tell my young co-worker: "A pi$$er yes, but one has to look at these kind of things as the character-building moments in life."

(I've come this far so I'm still going to finish mine though.)

02-25-2017, 11:29 AM
I had a frame drill for drilling truck frames, worked better than a mag drill for around bolts, rivets, close to other members, etc. Was on an adjustable cart & had handles & leadscrew t adjust the height & turn to move the drill when drilling.

02-25-2017, 06:27 PM
You can get some serious leverage with that set up.

Where did you get the nice ground top???


02-25-2017, 07:15 PM
You can get some serious leverage with that set up.

Where did you get the nice ground top???

JL................."Hey Joe, where you goin' with gun in your hand.." Oops, wrong generation.;)

It's a "Brute" machine table From American Grinding & Machine Co. in Chicago; weighs over 400 lbs. I got a deal on ebay and I'm loving it!

Story here: http://bbs.homeshopmachinist.net/threads/72931-A-new-CNC-project-begins!

02-25-2017, 10:59 PM
I'll bet you are loving it. I had a 3' x 4' 1 1/2" thick plate blanchard ground years ago for my welding table. It weighs about 600 Lbs.


http://i911.photobucket.com/albums/ac317/JoeLee09/Broaching%20Pulley%20Bore/Image001_zps0682b4b2.jpg (http://s911.photobucket.com/user/JoeLee09/media/Broaching%20Pulley%20Bore/Image001_zps0682b4b2.jpg.html)

02-26-2017, 12:20 AM
Ooohhh, me likey!