mills 1.3cc diesel mikes-models

24th February 2008 session 11

Well it wasn't such a bad session today. Practice on the second 'scrap' blank
went well. The boring bar I made yesterday performed well and I then tried to
cut the threads. Again it went fairly well. I must admit that I was hoping the
threads would have been cleaner and more pronounced in the second attempt
since the angle of the top slide was now correct. However it may be that I
require a 'chaser' to clean them up.

Since I couldn't see any advantage in using yet a third piece of aluminium, I
mounted the crankcase in the 4 jaw chuck, again using the wobbler to good
effect. Then I drilled the hole through the case as described in Ron's article (see
photo 1 below). Using three drills and the 0.75" end mill, I eventually got to the
position where I could start the boring.

This time though I had a couple of advantages over my practice on the other
crankcase blank. Namely, the dial indicator (see photo 2) to measure the depth
of cut for the end mill and secondly I re-mounted the digital readout on the top
slide so I could accurately measure the depth of boring.

I have now reached the position where I have just a little more to take off the
bore now and a little more depth, before I cut the recess and cut the threads,
hopefully tomorrow.........

Time spent today 2 hours 30 minutes. Total to date 21 hours. 30 minutes. (I bet Ron took no
more than a couple of hours to get here!)