Second round of update for the weekend.
First of all some "behind the scenes stuff.
This is my milling setup:
The picture is from a earlier stage. The clamp you see there is made to be able to mill the ends of the bridge frame since there isn't enough travel on the Z axis to stand the block on end.
The small grooves milled out on the right of the clamping block is to hold the smaller pieces I made earlier. One groove to fit 1/2" square stock and one groove to hold round stock.
When I milled the lid the aluminium sheet bent ever so slightly. (apparently hard aluminium have some degree of inherent tension). This is the setup I used to get the piece flat again. I knew I kept those pencils for a reason.
It doesn't show very well, but that is a broken drill bit. In a "moment of stupidity™" I was drilling some 2mm holes up to 2,5mm (I used a 2mm mill bit to place the holes and a 2,5mm drill bit to open up the holes for threading). For some reason I thought that a hand drill was a good idea.
I tried grinding around the hole and use pliers to get the broken bit out, but that didn't work. Time for some extreme measures:
A makeshift setup to bend the base plate from the frame. I then jammed some washers and hex keys between the base and frame to create enough space for the baseplate to clear the broken bit. I then used a hammer to knock the plate forward to get it out of the grooves along the side.
Incredibly this worked well and I managed to get out the broken bit.
This time I was doing the same thing on the headpiece (brass). Luckily I had the drill bit a bit loose on the drill chuck. (Drill press this time). I have never seen a drill bit twist like that. Usually they just shatter.
Ok, time for some progress:
Test run of the headpiece. It's just screwed down to a board. The bottom part will be below the surface on the final product.
I will be shaping the headpiece a bit more. I tried sanding drums in a drill press, but that was a bit too stiff to make a compound arch on the corners. I just couldn't find my soft sanding drum. I did find it when I putting back the tools for the day.
I'll finish it up next weekend I think.
Bottom view of the headpiece:
6mm grub screws to hold the strings and two 4mm screws to hold the headpiece to the headstock. There will also be a cover plate on the back of the headstock. (I haven't made that one yet)
Milling curves is pretty damn difficult. I'll fine tune them a bit more than they are at the moment.
I just had to give it a test run to see if everything works. Turns out it does.
I didn't tighten all the strings to full tension simultaneously, though. The board started bending a bit more than I was comfortable with. It had a pretty cool sound, but was a bit difficult to play with 15-20mm action.
This is how the bridge looks with strings:
I underestimated how little travel was needed to bring the B string up to pitch, though. Everything seems to be working perfectly.