Square holes with drill press?

[Bruce Page]

An unconventional method that makes beautifully square holes is broaching. You drill a pilot hole then using the DP as an arbor press, push the broach through. I picked up this broach and a couple of others off of eBay for very little money.

[Bill Dufour]

Broaches can also be made from hex keys. These are hardened steel and when sharp they can broach steel as well as wood.

[Ole Anderson]

Something to be aware of with the drill press mortising attachment is you really need a drill press with 5-6 inches of travel to do deep mortises. You lose some depth of cut as the attachment takes up space on the quill. The 3 1/2" of travel of my drill press quill limits me to shallow mortises. A drill press with 6" travel is ideal.

As long as your drill press table or head can be lowered or raised, I don’t see how this would be a problem.

[Robert Hazelwood]

An unconventional method that makes beautifully square holes is broaching. You drill a pilot hole then using the DP as an arbor press, push the broach through. I picked up this broach and a couple of others off of eBay for very little money.

Interesting. I have been trying to make square holes for square pins using a pilot hole and a hollow chisel, hammered by hand. Sort of works but I'd like a better method, and for now do not want to purchase a HCM.

These push broaches look like they'd cut very well, but seem to be pretty expensive. I have a couple of concerns- one is the length. Seems like you have to push it all the way through and they are at least 8" long. Most drill presses don't have that much travel, mine certainly doesn't. Do you take partial cuts and then keep raising the workpiece with spacers, or put spacers between the chuck and the tool? If so do you have any problems with keeping the tool aligned? Using a hollow chisel as a punch, one of the biggest problems is that the tool tends to rotate as it goes through.

The other issue is with spelching on the backside of the cut. With the hollow chisel I can work from both sides, but that doesn't seem very feasible with the broach. How bad is the spelching if you use a tight backer board?

[Stan Calow]

Corner chisels like these from Lie-Nielsen https://www.lie-nielsen.com/nodes/4175/corner-chisels are what I use. Much easier to register them on two sides.

[Bruce Page]

Interesting. I have been trying to make square holes for square pins using a pilot hole and a hollow chisel, hammered by hand. Sort of works but I'd like a better method, and for now do not want to purchase a HCM.

These push broaches look like they'd cut very well, but seem to be pretty expensive. I have a couple of concerns- one is the length. Seems like you have to push it all the way through and they are at least 8" long. Most drill presses don't have that much travel, mine certainly doesn't. Do you take partial cuts and then keep raising the workpiece with spacers, or put spacers between the chuck and the tool? If so do you have any problems with keeping the tool aligned? Using a hollow chisel as a punch, one of the biggest problems is that the tool tends to rotate as it goes through.

The other issue is with spelching on the backside of the cut. With the hollow chisel I can work from both sides, but that doesn't seem very feasible with the broach. How bad is the spelching if you use a tight backer board?

Robert, you do have to push the broach all the way through. I raised the table as I went. Once you have the broach started into the work piece an inch or two it becomes self-aligned so positioning or alignment of the table/broach/DP chuck is less important. I used a piece of ¼” MDF as a backer. As you can see from the pic, I didn’t have any blowout in the 1” thick QSWO.
After posting yesterday I checked out eBay to see what’s available. It’s been several years but IIRC, I paid ~ $100 for the 3 broches I have – much less than what I saw listed yesterday.

[Donald Hofmann]

I got the Delta mortising attachment for free with my Delta drill press. Even with sharpened chisels it was too hard to use. I then bought the Jet mortiser. I had to attach an extension to the handle to make it easier to use. I sold it and made a floating tenon jig for my router

[Derek Cohen]

Forgive this newbie question. I'm looking to make square holes or possibly rectangular cut outs using my drill press. Are there bits available similar to mortising bits but useable with the drill press? Thanks for your help.

David, I know that this is not what you asked, but I long ago rejected the drill press for morticing (as it is so inefficient and clumsy, and leaves a coarse finish), and instead use a router. I have a fixture that does this very easily, very accurately, and then (if you prefer, as I do) square up the ends with a chisel. Yell out if you are interested in this, and I will post pictures.

Regards from Vienna (currently)

Derek

[David Tolsky]

An unconventional method that makes beautifully square holes is broaching. You drill a pilot hole then using the DP as an arbor press, push the broach through. I picked up this broach and a couple of others off of eBay for very little money.

Nice! that's really cool.

[David Tolsky]

David, I know that this is not what you asked, but I long ago rejected the drill press for morticing (as it is so inefficient and clumsy, and leaves a coarse finish), and instead use a router. I have a fixture that does this very easily, very accurately, and then (if you prefer, as I do) square up the ends with a chisel. Yell out if you are interested in this, and I will post pictures.



Regards from Vienna (currently)

Derek

Yes I'd love to see pictures. I wouldn't even begin to know how to create a template for router plunging a square hole. I'm of course willing to square the holes up with a chisel.

[Derek Cohen]

Yes I'd love to see pictures. I wouldn't even begin to know how to create a template for router plunging a square hole. I'm of course willing to square the holes up with a chisel.

The fixture holds the router and clamps a board to it ...





boards clamped ...



Router set up ..





Regards from Perth ... Vienna at present

Derek