Brace drilling.

[MIGNAL]

3/4" auger/jennings using a hand brace to a depth of 3" in hardwood. Not very deep but it would be nice if I could drill accurately i.e. popping out the other side within 2 mm's (ish) of square.
What are the options, is there some type of guide that can be used?

 

[Bod]

Drilling vertically, or horizontally?

Bod

 

[bugbear]

3/4" auger/jennings using a hand brace to a depth of 3" in hardwood. Not very deep but it would be nice if I could drill accurately i.e. popping out the other side within 2 mm's (ish) of square.
What are the options, is there some type of guide that can be used?

A) Drill from both sides (this also reduces burst out/spelching)
B) drill through a piece of thick (e.g. 3") scrap as square as you can. Plane scrap
surface until hole is square to surface.

Fix scrap to workpiece, drill through the hole.

C) A and B together

BugBear

 

[AndyT]

If you are drilling vertically you can use one or two try squares to get the bit vertical by eye.

Or you can saw a notch at the end of an offcut of studding and rest the bit into the corner of the notch - Richard Maguire shows this in one of his videos.

Also, if your auger bit is the sort which scores round the hole to sever the grain, watch that it scores a full circle before it starts to dig down.

 

[MIGNAL]

Thanks guys. The piece can be drilled either vertical or horizontal. I'm just drilling relief holes so I don't have to negotiate tight(ish) curves with the bandsaw. I don't have the actual bit, as yet, although I have the brace. What bits I do have are the wrong size. The first and the last 4 or 5 mm's aren't relevant, it's waste.
BTW. Is there a particular type of bit that leaves a cleaner cut? The holes may well be the finished surface.

 

[Phil Pascoe]

Forstners.

 

[Cheshirechappie]

Is there a particular type of bit that leaves a cleaner cut? The holes may well be the finished surface.

Yep. A sharp one. Old-type centre bits (the non-screwed type) leave a nice, clean hole, but they're not very good at accuracy in deep holes. Jennings and Irwin pattern sometimes feed a bit too fast to leave a really clean finish. Might be wise to do a couple of tests in scrap. Finish will be better than a bandsawn surface, though.

 

[Scouse]

http://www.theenglishwoodworker.com/dri ... are-video/

 

[Phil Pascoe]

One of the saw building threads showed forstners being used to take the tight curves before cutting - I forget which, though.

 

[MIGNAL]

The first thing I did was try the forstner bit in the pillar drill. Less than half way through it started smoking :roll:. Obviously not sharp enough but I felt pretty uncomfortable drilling that deep with a very small pillar drill. It's not that fast either, given I had to clear the chips frequently, even when I swapped to a sharper bit.
I've just tried a 5/8 th's Clico in the brace and whilst it's not as clean as a forstner. . . it's good enough. It will need a very small amount of clean up. Pretty fast. They eat wood.

 

[bugbear]

Is there a particular type of bit that leaves a cleaner cut? The holes may well be the finished surface.

Yep. A sharp one.

:lol:

=D> =D> =D>


BugBear

 

[Racers]

If you put a large washer in the shaft of the auger when you are boring horizontally it will stay in the same place if you are level.

Pete

 

[xy mosian]

I find it easier to keep the hole square, and with less wobble, drilling horizontally.
A little candle wax rubbed on the bit will make the job easier too.
xy

 

[Sheffield Tony]

Some good tricks already mentioned, the two I might add are: have an assistant do the sighting for you, or use a mirror flat on the surface as an alignment aid - drilling through the hole in a CD can work.

Interesting you find drilling horizontally more accurate xy - I always try to drill vertically ! When chairmaking, the accuracy needed is much better than within 2mm in 3" ( =D> love the mix !). A chair stretcher might be 18" long, and more than 6mm out over that length looks very conspicuous. I use a pair of squares as AndyT suggests, or a square and a sliding bevel for angled holes - but only if it isn't possible to jig/prop the workpiece so that the holes can be drilled vertically.

Last thought: Scotch eye augers can be easier to sight, being long, and easier to turn without wobble than a brace. Although I feel slightly ashamed of myself for doing so in the light of Clico going under, I bought Japanese made single flute augers from Dieter Schmidt recently, and they are very nice to use, and leave a clean hole, and less than half the price of the Clico ones.

 

[MIGNAL]

Anything below 1/4" is mm's, anything above is in inches. Simple and perfectly logical.

 

[xy mosian]

Interesting you find drilling horizontally more accurate xy - I always try to drill vertically ! When chairmaking, the accuracy needed is much better than within 2mm in 3" ( =D> love the mix !). A chair stretcher might be 18" long, and more than 6mm out over that length looks very conspicuous. I use a pair of squares as AndyT suggests, or a square and a sliding bevel for angled holes - but only if it isn't possible to jig/prop the workpiece so that the holes can be drilled vertically.

Ah for the angled holes in chair seats I have the seat roughly horizontal and bore with reference to an angled block of wood.
Then I place the guide so that one edge, of the guide, runs down the length of the auger. That way I can see both compound angle and square from the operating position.
In the end I might change my method depending on the most suitable position for whatever is being bored.

xy