How have you drilled your bench dogs?

[Sawdust=manglitter]

Im in the middle of making myself a roubo-ish style workbench and just thinking ahead to when i'm ready to drill the 3/4" holes for the bench dogs. I've nearly finished laminating 4 sections of the top (so they fit in my P/T), but the finished bench top will be around 5" thick, so i want to make sure that the holes are all square. I've seen a few suggestions with people:
- using extra long forstener bits with a guide;
- using a router with a 3/4" plunge bit to start the holes and drilling the rest of the hole free hand with a drill (the starter hole keeping it square);
- using a drill guide (like this one... http://www.axminster.co.uk/axminster-drill-guide-500458) with either a long auger bit or a flat wood drill bit.

They all seem to have their benefits, but i wanted to know what methods others have used and recommend?

 

[Phil Pascoe]

If you or a friend has a pillar drill, you can drill one perfectly square hole through a piece of two or three inch scrap then clamp that down as a guide. There is a trick with an old CD if you search for it. If your top is that thick think seriously about counterboring the underside.

 

[Woodmonkey]

I used a drill guide like the one you linked using a beaver Eid bit from screwfix with good results

 

[RossJarvis]

If at all possible use a pillar/bench drill with no slack. Guides are helpful if well made. It's also helpful to put effort into getting everything well clamped and square to start with. On the whole I'd say it's nearly impossible to drill square handheld regardless of what anyone else may say.

 

[Biliphuster]

Out of interest, how important is drilling the holes square? I hand drilled the 1" holes in my bench with an auger bit and a brace and they seem to work fine even though I doubt the holes are that square. Seeing as the holdfasts kick over a bit anyway when driven I doubt a few degrees off matters much.

 

[undergroundhunter]

Mine were drilled with a brace and bit, I didn't use any guides of gizmos I just sighted for square. I can tell you the are not 100% square but they are close enough to work brilliantly. I wouldn't sweat over it too much.

Matt

 

[Sawdust=manglitter]

If you or a friend has a pillar drill, you can drill one perfectly square hole through a piece of two or three inch scrap then clamp that down as a guide. There is a trick with an old CD if you search for it. If your top is that thick think seriously about counterboring the underside.

That may be the most straight forward way of getting it done (so long as the bit is long enough). Thanks Phil! In terms of the counter boring of the underside, are you thinking in terms of the use of holdfasts to get a decent angle when hammering them in?

I used a drill guide like the one you linked using a beaver Eid bit from screwfix with good results

Due to the thickness of my bench top I would probably need an extension to this bit, particularly if I ended up using Phil.p's method. How much wobble do you think I would you get if I used some kind of an extension with these bits?

If at all possible use a pillar/bench drill with no slack. Guides are helpful if well made. It's also helpful to put effort into getting everything well clamped and square to start with. On the whole I'd say it's nearly impossible to drill square handheld regardless of what anyone else may say.

Trouble is, where I have my pillar drill in the workshop it's too close to a corner so there isn't enough space to be able to get them done all along the bench top, but I suppose I could move it to make sure I get enough room. What bit would you use in the pillar drill though?

Out of interest, how important is drilling the holes square? I hand drilled the 1" holes in my bench with an auger bit and a brace and they seem to work fine even though I doubt the holes are that square. Seeing as the holdfasts kick over a bit anyway when driven I doubt a few degrees off matters much.

It's probably just preference and me being a perfectionist (of sorts). With 1" holes did you make dogs for it? How do you get on with holdfasts in holes that size?

 

[RogerP]

http://www.axminster.co.uk/axminster-drill-guide-500458

 

[DTR]

I used a brace and bit, no guide

 

[thick_mike]

Brace and auger bit, no guide...a bit wonky, but they work fine.

 

[bugbear]

A cheap drill stand (from a car boot, coupla' quid) can normally have it's pillar swung round or reversed, making an ideal "good enough" guide for this job.

post915082.html?hilit=%20present%20from%20our%20lass%20#p915082

BugBear

 

[custard]

Get a 50mm plus thick block of stable timber, something about 150mm long by 100mm wide.

Mark the dead centre on one face, and pencil that centre mark with lines around the top face and two side edges and two ends.

Take the block to your pillar drill and, using the drill bit that you'll use for the dog holes, drill a 3/4" hole right through from one face to the other.

Pencil centre marks on the bench for the dog holes.

Line up your block with the bench centre marks (either using the lines around the block or by looking through the 3/4" guide hole and centring the bench dog centre marks, the first method is the more accurate)

Securely cramp the block to the bench (that's why the block needs to be 150mm long, so there's room for a couple of cramps)

Bingo, there's your drill guide! It's surprising how accurate this method is, a 50mm block will give you enough accuracy to drill 50mm-75mm into the bench, after which you can remove the block as the hole/bit will be self jigging for the remainder of the drilling on that particular dog hole.

If you want a bit more sophistication then permanently attach a small fence to the block so that it automatically aligns with the bench centre marks, then you just have to slide it along the bench edge between crampings.

Good luck!

 

[ED65]

I'd use a brace and auger too. I'm still re-amazed at how effective augers are every time I use them on thicker material.

If your OCD demands the holes are as perpendicular to the surface as can be you can use the old trick of setting up two squares at right angles to the point you're drilling, hard not to drill dead-nuts square with two verticals to refer to.

Or you could try the CD trick.

Or you could make a drilling block from thick stock [edit: just as Custard describes]. Clamp in place, thread in auger, start drilling and once you're down a few cm you'll not be drifting off vertical any.

 

[Bm101]

If you or a friend has a pillar drill, you can drill one perfectly square hole through a piece of two or three inch scrap then clamp that down as a guide. There is a trick with an old CD if you search for it. If your top is that thick think seriously about counterboring the underside.

That may be the most straight forward way of getting it done (so long as the bit is long enough). Thanks Phil! In terms of the counter boring of the underside, are you thinking in terms of the use of holdfasts to get a decent angle when hammering them in?

I used a drill guide like the one you linked using a beaver Eid bit from screwfix with good results

Due to the thickness of my bench top I would probably need an extension to this bit, particularly if I ended up using Phil.p's method. How much wobble do you think I would you get if I used some kind of an extension with

From memory I think I read the optimum depth for holdfasts is about 3 maybe 3 1/2" If you used Custard's method to sort squareness and mark your bit so just the spur breaks out the underside you have your mark to freehand a slightly bigger bit into the underside to get the desired depth for your holdfasts.

Look at me giving out advice like I have a clue what I'm doing! Bleedin' Internet Woodworker!

 

[Nelsun]

A router with an appropriately sized bit and a good plunge depth could get you started. You'd be good and square and have a nice... er... clean hole!

 

[Phil Pascoe]

Custard explained my way perfectly. Of course you don't need to drill all the way through the bench with the block in place, you only need to start the holes off. If you then drill through until the tip just breaks through the underside and no further you'll have the centre to start the counterbore.

 

[shed9]

+1 for Custard's method, it's simple and achieves the required end result with minimum effort or extra equipment outlay. The only issue may be having suitable clamps to grab the block in the right position.

 

[Biliphuster]

Out of interest, how important is drilling the holes square? I hand drilled the 1" holes in my bench with an auger bit and a brace and they seem to work fine even though I doubt the holes are that square. Seeing as the holdfasts kick over a bit anyway when driven I doubt a few degrees off matters much.

It's probably just preference and me being a perfectionist (of sorts). With 1" holes did you make dogs for it? How do you get on with holdfasts in holes that size?

I only used 1" holes because had a 1" holdfast. You have to hit it very hard to get it to set, but other than that I doubt it differs much from any other holdfast. I just use bits of 1" dowel for dogs, nice and easy to shape to specific purposes as well.

 

[Dan j]

I used a drill guide like the axminster one. Make sure you take your time setting the drill up vertically as there tends to be a bit of play where the drill collar attaches to the guide.