Drilling Perpendicular Holes w Spade & Forstner Bits?

[Steve H Graham]

I'm going to reveal my shameful secret: I can't drill holes perpendicular to my work.

I was putting bench dog holes in my bench top, and I figured I would try the trick I saw on a Youtube video. I would put a V-shaped notch in a thick batten and use it to support the bit so it cut straight. Then I realized this will not work for spade OR Forstner bits. I could have used a Silver & Deming bit, but I hate to ruin them on wood.

I got out a Craftsman gadget with two springs on it. It's supposed to hold the drill at a fixed angle to the work while you drill. Apparently it doesn't. I have one hole that looks like it's a solid 5 degrees off vertical.

So what's the answer?

[Jim Dwight]

My Ryobi cordless drills have little levels on them. They help. Holding a square up to the drill to sight against also helps. If I really have to drill straight and can't use the drill press I dig out a parallel rod guide. It has a separate chuck. Works well but it's one more thing to manage. Another good way to make a bunch of holes perpendicular would be to use a plunge router.

[Kent A Bathurst]

Set wood blocks at 90*, so you can see plumb in 2 directions. Get in position where you can sight along the bit/shaft v the references and start drilling - less than Warp 4 - keeping it sighted in.

Stand up a bevel gauge if you have one angle that is not 90*.

Or - use bevel gauge @ 90* and / or squares - whatever - for reference.

I have tried 2 of those gadgets where you mount a drill to use as a guide-type-drill-press-mimic-thing. Never held true. Must be something out there, but this is a rare event, so I just take my time and do it carefully.........

[Eric Schmid]

Plunge router seems like the right tool for your job. You could do the layout on a template so you're not practicing on your table. The template can be a strip of plywood that you drill/route the layout holes in. Lay it out on the table and trace the holes with a pattern bit on a router. If you've got a drill press the template could be made on there. Two parallel rows on the template will give registry points for parallel rows on the table.

[Mike Schuch]

I have a 30 year old little bench top drill press pretty much worthless for anything but... I have swung the table out of the way, lowered the head, and cut out a hole in the base. It did an excellent job on perfectly perpendicular bench dog holes.

[glenn bradley]

I fought non-perp dog holes for the last time and switched to a plunge router.

[Roy Harding]

http://www.busybeetools.com/products...ilescraft.html

i did one bench with a plunge router, and one with a drill guide as at the link. Both worked. I'm on my iPad, so I couldn't post a proper link, you'll have to copy and paste the link.

[Ken Andersen]

Modify your v-block so it can accommodate the cutter portion of your forstner or spade bit while the shaft of the bit rests in the v. Here's one way to do that: Make a backer board for your v-block. The backer board thickness should be slightly more than the total length of the cutting portion of your bit. Mount the v-block so the bottom of the v overhangs the edge of the backer by at least the radius of the bit.

[Kent A Bathurst]

I fought non-perp dog holes for the last time and switched to a plunge router.

Dunno why I did not think of that. Ignore what I said. Go with Glenn.

[Keith Outten]

A plunge router seems to be the best answer in this case as mentioned.

Another option is to borrow or rent a magnetic drill which are made primarilly for metal drilling so they are generally very heavy duty and accurate unless they are worn out. You can lay a large piece of flat bar on your wooden table top and use clamps to hold it securely to the top. At that point you can engage the mag drill magnet to the plate and drill your holes.

We have discussed magnetic drills here before as they offer a means to drill holes without the drill bit to column limit you normally have with a drill press. Very large holes are possible using hole saws, mag drills are made for this kind of work.
.

[Jim Wheeler]

I'm not sure how drilling wood could hurt a Silver and Deming drill that is intended for metal, but be that as it may...
You could use the shop-made guide with the v-shaped notch to drill a small pilot hole first with an ordinary twist drill or brad point bit. The spade bit will follow the pilot hole, if you're careful - as will the Forstner if it is one with a brad point.

Btw, rather than a batten with a v-shaped notch, I like to use a hardwood batten that has been drilled on the drill press to form a perpendicular guide. I've even used such a guide to drill dowel holes with good results.


Jim

He who welds steel with flaming pine cones may accomplish anything!​

[Brian Tymchak]

... I like to use a hardwood batten that has been drilled on the drill press to form a perpendicular guide. I've even used such a guide to drill dowel holes with good results.
​

this is what I did to drill dog holes. My bench top is 3 1/2" thick so my plunge router wasn't going to cut it. I grabbed a scrap of 8/4 Ash long enough to span the bench top width-wise and drilled 3 holes on the drill press in the exact spacing I wanted across the bench top. Then clamped that pattern guide onto the bench where I wanted and drilled the holes using the guide to stay straight. I also clamped a board on the bottom of the bench to minimize tear out as I was using a twist bit. I used a trim router to put the very lightest chamfer I could on the tops of the holes to eliminate any future splintering.

[ryan paulsen]

I haven't used these, but am considering them for when I build my bench:

http://www.leevalley.com/US/Wood/pag...02&cat=1,41637

[Robert Engel]

I haven't used these, but am considering them for when I build my bench:

http://www.leevalley.com/US/Wood/pag...02&cat=1,41637

Drill the dog hole strip before you laminate the top and you can make a nice job of it on the drill press.

Suggestion: figure out where your vise will go before you drill the holes to avoid having holes that end up over the vise frame (how do I know that?)

[Reinis Kanders]

I just used that bushing, worked great.

I haven't used these, but am considering them for when I build my bench:

http://www.leevalley.com/US/Wood/pag...02&cat=1,41637