drilling big holes

[Ralph Boumenot]

Hi
I'm thinking of building a new workbench and putting in a wooden vise and screw. The required hole for the screw is 2 5/8" and the cheapest bit I can find that big is about $130. Wee bit more then I want to spend. Is there some way to make this hole with out shelling out so much money for the one time I would use this drill bit?
thanx
ralph

[Mark Dorman]

Look for Irwin® Drill Press Adjustable Wood Bit, or expansion bit. Way less than 130 more like under 40 bucks. Practice on a test board first so you know what to expect.Mark

[Bruce Haugen]

sent a pm with a reference

[Ralph Boumenot]

thanx Mark, I'll google it and see if it will work. Still in the planning stages and I want to line up my ducks and get them all quacking as one.
ralph

[Jack Curtis]

I would saw it out rough then use a smallish spokeshave to smooth it. Alternatively, you could make the opening oversized square, into which you could insert a separate square, which could be cut apart for shaping a hole in the center.

[Derek Cohen]

Hi
I'm thinking of building a new workbench and putting in a wooden vise and screw. The required hole for the screw is 2 5/8" and the cheapest bit I can find that big is about $130. Wee bit more then I want to spend. Is there some way to make this hole with out shelling out so much money for the one time I would use this drill bit?
thanx
ralph

Hi Ralph

Draw the circle (2 5/8").
Now drill a series of adjacent holes inside the perimeter. I would use a 1/4" bit to get them closer together.
Chisel/rasp out the waste.

Regards from Perth

Derek

[Zach Dillinger]

Hi Ralph

Draw the circle (2 5/8").
Now drill a series of adjacent holes inside the perimeter. I would use a 1/4" bit to get them closer together.
Chisel/rasp out the waste.

Regards from Perth

Derek

This would be my choice.

Zach

[Jim Matthews]

+1 on roughing out the larger hole.

I mounted two recessed 2" nuts in my Moxxon vise just this way.
This could be cleaned up with a router in a circle template if you wish to avoid handwork.
(I would do it by hand, that way you won't likely overshoot your desired dimension.)

[Jessica Pierce-LaRose]

Drill a few holes and paring to fit is what Chris Schwarz shows in the workbench book, although I think he started with larger holes than the 1/4" derek recommended.

What about a holesaw? Probably have to drill down a bit, knock out some waste with chisel, and repeat, to get through the thickness of the leg. The larger sizes can be a bit pricey if you're buying fancy, but you might be able to find someone with a set and borrow one, as they're pretty common.

[Sean Hughto]

Um, here is one for less than $30. Many other brands are on the market that may be slightly more, but are far under $130.

http://www.grizzly.com/products/Larg...t-2-5-8-/G1828

[Jerome Hanby]

Look for Irwin® Drill Press Adjustable Wood Bit, or expansion bit. Way less than 130 more like under 40 bucks. Practice on a test board first so you know what to expect.Mark

I bought one of those a while back for some long forgotten purpose that I never fulfilled <g>. How well does it work?

[Mark Dorman]

As long as there is something for the center of the bit to grab it's not bad. You want a backer board to keep from having blowout.
If you drill a hole then want to go bigger it won't work.

Mark

[Jan Weiner]

I haven't had much luck getting clean holes with the expansion bit and would definitely recommend the hole saw. They are about $15 at the borg including the mandrel. For another $10 there are extensions to reach the depth you will need. I used a #2 philips to snap the waste from the hole as the hole saw hit bottom. If you are looking for a clean exit on the inside of the leg, just use a long 1/4" bit to drill the pilot before starting, and then drill through from both sides. Definitely use a drill with a pigtail. Batteries just don't have the power to drill that size hole.

[James Owen]

Heresy that it is -- on this forum -- if you have a drill press and the work pieces will fit on it, a circle cutter might also work.

[Jessica Pierce-LaRose]

I actually use holesaws in my brace quite frequently - I've a little setup for drilling holes in some jar lids my wife makes into soap dispensers - ( I should really get a punch for that thin metal but I don't even know where to start with that ) and also for chassis holes in aluminum plate for things larger than I want to use my step bit or twist bits for. They work quite well, but the thing to beware of (and the same thing goes for step bits) on these with two jaw chucks is that while a round or hex bit will work okay in a tightly grabbing chuck (my yankee drill does particularly well with round bits compared to my other braces) is that a lot of the arbors for holesaws aren't actually hex shaped - they just have three flats ground on them. This works find in a three jaw chuck, but for a two jaw chuck, it means that there aren't actually two parallel sides anywhere on the bit - even if you can get the chuck to grab the bit, it's going to be horribly off-centered and unusable. Just something to keep in mind.