There are dozens of ways to drill dog holes that dead-nuts plumb, and I’ve written about many of them during the last 17 years. My favorites use the fewest tools and jiggery – not everyone has a big plunge router with massive bits or can clamp a drill press to the benchtop.
This method uses a 2×4, a drill and a bit.
First you need to drill a plumb hole through the width of the 2×4. If you don’t have a drill press, here’s how: Mark a centerline on both long edges of your 2×4. Mark the location for the entrance and exit hole on the 2×4. These marks should be aligned. Drill through the 2×4. If your entrance and exit holes both hit the mark, the hole is plumb.
Now clamp the 2×4 on edge to your benchtop and use the plumb holes as an oversized doweling jig to guide your auger bit. The length of the 2×4 will allow you to put holes anywhere you please on a benchtop.
Oh, and why should the holes in your benchtop be plumb? Everything works better. Your holdfasts will hold consistently. Your dogs will grip the work more tenaciously.
— Christopher Schwarz
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Chris,
Its not about this subject but I want to ask a question.I dont live in US and its almost impossible to find 6×6 slabs for 18th Century Roubo Workbench.Is it okay to use 4×6`s for this workbench.(The thickkness will be 4”)
Ah, there’s that wasskerly wabbit Wohman bench again!
Is that a WoodPwl bit? I have a 7 1/2 inch long WoodOwl bit # 09709 – yours looks to be closer to 12 inches. I’m sure the hole in the bench can be started with your method and then finished with the 2×4 removed. I’ll be working with a 4 1/2 inch Roubo. Do you measure the depth so as to avoid cutting all the way thru and then finishing up the cut from below the bench?
Thanks for all that you do for the woodworking community.
David
I put a square on the bench and went at it by eye with a brace and auger bit. Thought that was good enough for holdfast. Thought holdfasts held pretty well but any improvement is welcome. Do think a larger holdfast, rough finish and more pronounced taper may do a tad more to hold.
Chris, I just want to say thanks one more time for all you have done for the woodworking community. Happy Thanksgiving.
PS – My family and I can not wait for your yearly gift suggestions. Your suggestions protects me from receiving socks and more Starbucks gift cards!