Dog Hole Spacing

[Alan Lightstone]

So, in my workbench/assembly table renovation project I've decided on a pre-made 2" top.

It will be a very generous size (74"L x 32" W x 2" D)

I for a while have had a Woodpeckers Hole Boring Jig which I was planning to use to make 3/4" dog holes on the top.

The spacing on the jig is 3-3/4" on center which strikes me as pretty close together. I was planning on 4" spacing.

Is 3-3/4" too close together for dog holes?

Will that many holes significantly decrease the strength on the top (It is 2", but still)?

What other manufacturers of hole boring jigs might give me better spacing? (Really don't want to buy twice, but...)

[David Publicover]

Hi Alan,
I’m not sure what the consensus is on spacing but I have 4” centres between my dog holes and wish it was closer. Perhaps the fact that I use a Veritas Twin Screw vice as my end vice is a factor as it is somewhat awkward and slow for that task. I’m planning on adding some extra holes on 2” centres to check it out before I build a new bench. I don’t expect it to affect the strength significantly.
Best regards,
David

[David Bassett]

Chris Schwarz's latest Workbench book talks about dog hole placement pretty extensively. (It's free as a PDF download. The Anarchist's Workbench (https://lostartpress.com/collections/books/products/the-anarchists-workbench), with download link on that description page.)

IIRC- the row of dog holes inline with a tail vise is chosen to complement the tail vise's travel, so you don't leave pieces you can't clamp without a spacer. For other dog holes a much larger spacing is used, with just enough to give good coverage for using holdfasts.

PS- OTOH- if you're planning a Festool clamping / work table with a hole grid, use their size & spacing so you're compatible with all their accessories.

[glenn bradley]

Based on travel or in the case of my long travel vise, how far you want to travel between grip points. I picked about 6". I say about because I evenly divided the length I was using. This is very usable. Trying to predict what the next dimension is that you may want to grip tomorrow is unrealistic. Plan for the length of travel you are comfortable with.

[Jim Becker]

The spacing range you mention is "within norm". The Festool grid is 96mm oc which is just under 4", for example. The actual spacing doesn't matter all that much as long as it's the same and exactly placed if you intend to index for square off the grid.

[Andy D Jones]

If you use hold-fasts, I would think the hole spacing would also depend on their reach.

-- Andy - Arlington TX

[Alan Lightstone]

I actually read both Chris Schwartz's workbench book and Lon Schleining's workbench book yesterday. (I need to get a life. :rolleyes:)

They're a little wishy-washy regarding placement.

I think I'll stick to the Woodpecker's distance which is 3-3/4.

Of course that means I'll have to rout out 152 holes. Do I need to buy several bits because they'll get dull? I've never remotely made that many holes.

[Andrew Seemann]

I don't think I have used a bench where I wished the dog holes were spaced further apart. On my current Frid bench I decreased the spacing on both the bench and tail vise, and am the happier for it.

Regarding your bit, you could probably hit it with a file or on a grinder if it starts getting dull. Sharpening drill bits is a handy skill to learn.

[Chris Schoenthal]

Of course that means I'll have to rout out 152 holes. Do I need to buy several bits because they'll get dull? I've never remotely made that many holes.

Probably a pain to do with that many holes, but I've pre-drilled using a 1/2" drill bit, so the router bit doesn't have to work so hard.

[Michael W. Clark]

I built an assembly bench last Christmas. I didn’t put any holes in it or a vice on it. My workbench has holes and vices. When I use the workbench for assembly, I’m always trying to keep small parts from falling through the holes.

[Jim Dwight]

I would definitely pre drill with at least 1/2 inch bit, 5/8 would be better. I did the top of my 3x7 assembly table with one bit but the top surface is just 3/4 plywood. I pre-drilled, after trying a few holes without it. The noise and smoke convinced me to drill. I was making 20mm holes for track saw accessories (clamps, Festool clamps and dogs).

[Alan Lightstone]

Interestingly, Chris Schwartz in the Anarchist's Workbench has the hole spacing 15" between holes, and 3-5" from the edges, which is way too far for how I work with various hold downs.

No question I'll line up the holes on the end-vise with the holes on the workbench top.

[Alan Lightstone]

I built an assembly bench last Christmas. I didn’t put any holes in it or a vice on it. My workbench has holes and vices. When I use the workbench for assembly, I’m always trying to keep small parts from falling through the holes.
No question that's going to be an issue with my design. I'll have to do something to prevent small parts from falling through into the drawers.

[Alan Lightstone]

Ok. To show how busy I've been in retirement, I'm now just getting around to planning and drilling the holes in my workbench. I have mixed feelings regarding keeping the top with no holes, and adding dog holes in it.

My Sjoberg's workbench is really too small for a number of projects I've built. So this bigger surface having dog holes would get use. It would also be a huge pain for small parts to fall in it (though they would fall into drawers below, so not a deal breaker).

I experimented with the Woodpeckers jig for making dog holes. It's an unmitigated disaster. No way I will use this for the workbench. Takes way too long, and the holes don't come out evenly. Thankfully I first practiced on scrap wood for that.

So I purchased the Parf MK II Guide System. After practicing this in scrap wood, that will be my method.

So back to the question I asked last year. What are people's thoughts as to the spacing of the dog holes, and should I perhaps just drill them on the left side of the workbench top near the vice, leaving the right side solid to prevent parts from falling in?

[ChrisA Edwards]

I did about half, of my top, with full dog holes and a couple or rows on the outside edges the full length. Can't say I've found a need for more holes yet.


https://hosting.photobucket.com/albums/i452/cedwards874/Woodworking/Bench%20Dog%20Top/.highres/BenchDogTop2_zpsvpkrlszb.jpg

[Jim Becker]

I adopted the same 96mm on center that Festool uses for the MFT for any surface that I've done the dog hole dance. The Parf system may actually already be setup for that spacing.

[Charles Lent]

What is the range of the vice that you will be using to clamp against these dogs? You want the dog spacing to be spaced less than the maximum travel of the vice lead screw, or to speed up things when it's in use on smaller projects, increments of about half of the maximum travel of the vice.

Charley

[Edward Weber]

I actually read both Chris Schwartz's workbench book and Lon Schleining's workbench book yesterday. (I need to get a life. :rolleyes:)

They're a little wishy-washy regarding placement.


They're "wishy-washy" on nearly everything.

[Alan Lightstone]

They're "wishy-washy" on nearly everything.

Yeah, read them both a while ago, and didn't have a great answer to my question.

[Alan Lightstone]

I adopted the same 96mm on center that Festool uses for the MFT for any surface that I've done the dog hole dance. The Parf system may actually already be setup for that spacing.

I plan on using that Parf system spacing (I think you're right, Jim, that it's 96mm.) I'm really thinking seriously about leaving about half of the top without holes, or with very few, and the rest with the 96mm spacing. But I keep running into projects that require dog holes farther away from the edge or vice than my Sjobergs workbench has.

[Jim Becker]

Play with it on paper a bit, Alan. You can easily do a grid of 96mm spacing in part of your work surface and use a wider spacing that's still aligned with the 96mm "virtual" grid to keep things consistent. I took this one step further with my primary and guitar benches in that I have the 96mm grid of 20mm holes as the general field, but also have some .75" dog holes in thicker support areas to allow me to use my "coveted" Gramercy holdfasts. Some folks incorporate some slots within the grid to permit use of their F-clamps, etc. Figure out what would enhance how you work and "do that". You could even take the time and make a prototype top or two to experiment...MDF isn't all that expensive in the general scope of things.