I bought this set of trammel points from
Lee Valley Tools, years ago.
They clamp to a piece of wood to form a compass.
And I though I should get one for the other shop
but then I came up with this design
which worked out really nice except this is
just a hack. So, in this video,
I'll build it again and a bit more precisely.
The points clamp to this dovetail rail and I'll
start by making that part.
Dovetail rail cut.
Now for the brackets. I'm gonna make those
out of this wood. And I think
this wood will contrast nicely, especially once
its been varnished.
I cut these ones upright on the bandsaw
but I think for this one I'm gonna cut a
dovetail on the table saw before I cut
individual block out of it.
But before I do that, I have to drill some
holes in here because the hole for this pencil
overlaps with the dovetail so I should drill
that first.
That cut needs to cut away part of the hole
so that when I put a pencil in here, I can
clamp against it by pressing flat against here.
Before I cut this rail into individual blocks,
I might as well also drill the hole for this
quarter inch bolt through here.
And on one side it slides loosely and the other
side it's sized so that it's tight.
I also just drilled the holes for the screws that
go through here and
2 of these holes are sized so that the screw
fits in here loosely and 2 of them so it engages
just a bit.
I'm afraid if the thread is too tight I might
split this block of wood so I ground a screw
flat on the front and just by screwing that
in there, I can pre-cut the threads in the wood.
And now for the actual screws.
Back that out a bit more to get the pencil in.
And now as I tighten these screws that block
gets squished tighter against the dovetail
and that locks the pencil in place.
The screw fits more tightly in this block here so
a bit more work to twist it in.
So, with everything being machine operations
I figured I might as well make parts for 2 in case
I screw up. And I didn't split this block here,
I counter-sunk it, but I glued it back together
so now I have 2 new beam compasses
plus my prototype,
plus the one from Lee Valley Tools.
So, I think I have enough compasses now.
Compasses can be so much fun.