mills 1.3cc diesel crankcase model engineering mikes-models

27th January 2008 session 7

I have now finished the profiling of the bottom of the crankcase (see photo 1 below). I also
have to admit that I made it all the more difficult because I didn’t ‘read the %^$question@!
As they say. In Ron’s article it shows a photo of his profiling and there the lines clearly match
his text in saying that you use the top slide (x axis) to make the cut’s, then move the chuck for
the next cut. I, for some reason decided to go my own way!!! And went off on a tangent,
literally! I maintained the top slide in position then moved the chuck to take the cut.
Doh….However all is not as bad as it could be as the finish is not too bad and will be ok on
final polishing.

Now this part of the construction is finished I removed the piece and replaced my ‘practice’
crankcase in the 4 jaw chuck, resetting it to run true with the aid of my ‘wobbler’ and dial
indicator. Following Ron’s article I centre drilled the crankcase and followed up by drilling
through using firstly, a 3/16th drill, then a 9/32nd drill.

The next stage was to drill to a depth of 9/16" with a ˝ inch drill (see photo 2 below). It was
at this point I had to stop because I need to flatten the crankcase hole by using a ľ inch end
mill or slot mill. Fortunately I have the end mill but no way of holding it in the tailstock of the
Turner 280 GV lathe. It has a MT2 taper and my collets chucks are both M3. I thought
immediately of using an adaptor because a chuck just for the Turner lathe seemed
unreasonable and funds have to be considered! Looking on EBay and my favourite suppliers
sites I found that the only ‘cheap’ way I could overcome the problem was to have an
extension with the MT2 taper outside and in the extension piece an internal MT3 taper. So its
now on order and I will await its arrival. Watch this space……..

Time spent today 1 hours. Total to date 12 hours.