Belt Sander for Drills and Tool Bits

Canuck75

Active User
H-M Supporter Gold Member
Joined
Jan 1, 2014
Messages
236
Have been regrinding my drills by hand so was really interested in the threads on this subject (Lets Talk Drill Grinders), and, also that the small swivel grinding attachments can do a decent job. Got one and set it up to use against a grinder wheel. Soon thought it would be nice to use it against a flat platen vice the curve of a wheel (or side), then wanted a better way to control the grind than flipping the drill as one went along. The result was a conversion of one end of a grinder to a belt sander and making an adjustable base to control the attachment.
Started by removing one end casting of the motor and turning a shoulder for a mounting ring to which the sander frame (1/4” x 4” flat bar 44W) is bolted. Used the lathe DRO and a probe to act as a CMM for checking how much casting was left at the thinnest point, which was .250”, so figured that was still strong enough. The drive pulley is 4” OD x 2-1/2” wide 6061 AL with a .010” crown which drives a 2x28 belt at 3600 SFPM. The take-up pulley is 2” OD on ball bearings mounted in a yoke. Had several ideas for tensioning the belt but in the end used a thumb wheel against a spring on the yoke shaft. Two thumb screws adjust the tracking by acting against a small tab attached to the side of the yoke. The twisting action controls the tracking very nicely. A platform at the bottom of the frame supports the swivel grinding attachment. The adjustable base makes it easy to grind one side to finish, flip the drill, then feed the second face forward to the same exact position. Among all the other necessary bits and bobs the fixture base was milled it out and fitted with a block of 6061(+ JB Weld) to accommodate tapped holes and an underside channel to fit and slide on a rail on the base. The graduated dial has .002” increments which gives accurate control via a 7/16”-20 TPI feed screw. An added plus is that the fixture can easily be moved side to side by loosening one thumb screw underside so that you are not using just one spot on the belt! Also the whole fixture is easily removed by loosening the same thumb screw and sliding it off sideways. This frees up the sander for an accessory adjustable platform with 0 to 45 degree movement for normal sanding and grinding tool bits.
Have ground 1/8” to 1/2” drill bits so far. The larger bits look very good compared to information by Joseph Mazoff gleaned from this forum. The 1/8” bit has too much of a chisel angle so will have to work that out.

Thanks for looking.
Canuck75

IMG_9547.jpeg

IMG_9563.jpeg

IMG_9572.jpeg

IMG_9591.jpeg

IMG_9593.jpeg

IMG_9599.jpeg

IMG_9601.jpeg

IMG_9603.jpeg

IMG_9605.jpeg

IMG_9608.jpeg

IMG_9610.jpeg

IMG_9617.jpeg

IMG_9620.jpeg

IMG_9621.jpeg

IMG_9626.jpeg

IMG_9628.jpeg
 
I must say I'm impressed. I've been considering purchasing a 2" wide belt sander like a Burr King, but at prices ranging from $2,400.00 to $3,600.00 they're a bit pricey for the use I'd give them. Your idea looks like something that could be used for multiple sanding/grinding jobs, and cost a fraction of a Burr King.
 
I must say I'm impressed. I've been considering purchasing a 2" wide belt sander like a Burr King, but at prices ranging from $2,400.00 to $3,600.00 they're a bit pricey for the use I'd give them. Your idea looks like something that could be used for multiple sanding/grinding jobs, and cost a fraction of a Burr King.
The AL, steel, and screws cost just over $100, couldn't even give a figure for labour. Could have bought a combo Busy Bee grinder/sander for $150 but that would be no fun, would also mean I'd have a third grinder!! Made the dust collector from an old cookie sheet so even got to do a bit for recycling!
Thanks for your comment.
 
Made some further mods. Noticed some drill shanks lifted slightly in the tailstock V when clamping. Fixture parts are die cast thus not exactly precision. Set it up in the mill and shaved the Vs as a unit. Made a tailstock clamp to make sure they sit properly in the V and also to hold a stylus to back the smaller drills which only sit in the front V.
Attempted and have actually ground down to 1/16" bits with a 120 grit belt. Lining up the cutting edge is the biggest problem.

Cheers

IMG_9634.jpeg


IMG_9640.jpeg
 
Back
Top