A customer of mine asked me: "when do you use an angle base boring machine?"
As my machine is a fixed base machine and I've only ever used it to do straight mortises, I didn't have an answer.
So, my question to you timber framers out there who have angle base machines is "when do you use an angle base machine?" And how do you start the lead screw on an angle?

Jim Rogers
Jim Rogers Sawmill

Drill at angles for slanted mortises or slanted pockets.
Create an angled shoulder for the bit if neccessary, but the bit should cut in at smaller angles
any boring machine will drill at angles if you place tapers under it...
We last used angles building a set of timber sawhorses which had mortises angled at a 3/12 pitch
-Mark.

Hi Jim
I can think of one instance where we were dealing with 6x8 knee braces that used 1 1/2" ash splines as tennons. The mortise was a through mortise on the 8" face of an 8"x12" post. We removed most of wood using a chain mortiser, however the machine will only mortise 6" when its perpendicular to the timber. After turning the timber over and doing the other side the waste in the middle was removed with an electric chainsaw! It was little like chainsaw art in the middle of the timber.
I don't know how long an auger bit a boring machine will accept, but an 18" x 1 1/2" auger bit in an electric drill with the drill guide set to 45 would have made more sense....in hind site.
I haven't tried this but I also thought boring machines set at 45 might work well to cut rafter seat cuts that are not on the shoulder but rather further in on the plate. Just my 2 cents worth. I'm Canadian so that's probably 1.4 cents worth :p
Ian.


Gee, I hope this image thing works.

Great to see a photo, Ian...good looking work!(particularily like the Tim Horton's coffee cup)
I think 45 degrees would be too steep for a boring machine unless you create a spot to start the bit, better to drill straight down to the intersection and clean out probably.

-Mark(near peterborough)

An adjustable boring machine would also come in handy for making mortises for a traditionally framed valley joining two roof pitches. There is a great desription of the joinery required along with a spread sheet calculating all the angles for you in the members only section. courtesy of Ed Levin. My boring machine is fixed, but I may give it a try by shimming the base as Mark suggested.

Peterborough, aye? I did a triathlon there a few years back. Very nice town.

shaun

Hello again,
I should add Photo courtesy of "Tim BR Frame" and that's my boss's Tim Horton's cup. I hope he rolled up the rim! I'm sure Mark will get that one.

Hey Mark, I used to go to Trent U. I should send you an email. Were practicly neighbours!

Ian