I've decided to mill the curve on the target plates. I need the rotary table on for this so the vise came off. I decided to check its base to make sure it was flat. Castings move over time and it's a good thing to check every now and again. The easiest way to do this is to draw file it with a big flat file....
Here's the result, worth doing, I took it down until I was hitting the high spots all over. It was most out of truth on the edges and round the central hole. I could go further and grind it dead flat on the surface plate but there's not a lot of point because it's probably more accurate than the bed of the VM! We're talking a tenth of a thou here....
Next I did something I have been meaning t6o do for a while. The central hole on the rotary table is 3/8" Whitworth so I faced a 3/8" setscrew and gave it a centre hole.
Using a pointer in the chuck it's now dead easy to set the rotary table dead on the centre line of the VM. That's the crucial condition for milling curves....
I picked a cutter out and got set up but it was really dull. We need a better cutter!
I sorted out another, much sharper cutter. You can tell by the chips that I am getting a good cut. If you're wondering why the welding glove, I was using the table stop to regulate drag on the turning motion and the hot chips make it most uncomfortable.
Cutting perfectly. I was taking 50 thou with each pass which is a good cut for my El Cheapo mill. I was soon down to a perfect half circle with a good finish.
I got set up again and cut the second plate. A perfect example of the gains in making more than one engine at once. Twelve minutes cutting, that's all it took.
Knocking-off time. Not a bad result and another step forward. I've put the rotary table away, had a chip chase and put my normal 3/4" cutter back in the mill. I'll vacuum the carpet tomorrow! Nice morning.....
