I was in two minds on how to make the "frame" structure that supports the flywheel and side levers - laser cutting would have got nice internal corners but as I have the CNC that was also an option and I could always square up the corners with a file.
In the end I decided to use the CNC which did not work out as I had hoped. All was going well on the first piece then the swarf suddenly started to come off red hot with some sparks which took the edge off the carbide cutter but it carried on just throwing up a bit of a burr. The next time it came to the same part of the cut it was sparking again and then really struggled and broke soon after. Put in a new 3mm carbide cutter and it happened again. So looks like there was a hard inclusion in the 2.5mm steel sheet which I have had a couple of times before with steel.
Rather than buy some more 2.5mm sheet and replacement cutters I decided to produce the files and sent them off to Lasermasters who sent these back within a week
The base and vertical plate were milled up from 5mm sheet without incident as was a piece that will be machined to form the pads that the two bearing pedestals bolt to. These were then wired together and silver soldered.
After a quick sand blast they cleaned up quite well with the solder having flowed well down the inside corners and out into the joint, just a few small gaps where the tabs did not completely fill the matching notch and the solder could not bridge the gap.
I could now start machining it so fixed it to a machining plate which was clamped to the lathe cross slide so the bottom that was left over thick could be cleaned up and brought down to the right thickness.
Then over to the mill to finish the edge of the base and I also skimmed the ends of the bearing supports to the same hight (more to come off them later).
That gave me three points to sit on the mill table so the vertical plate could be milled square to the base as well as drilled & tapped.
The bearing supports were then milled to height and their ends trimmed to the final length as well as drilling and tapping for the pedestals.
Lastly the arm pivots were milled to length and drilled & tapped for the pivot pins.
Quick trial fit and all look well.
Part 1 here part 2 here part 3 here Part 4 here Part 5
