ETA 15D MK 3 AND ELITE - 5cc ENGINE BUILDS
Part six - by Ramon Wilson
Part four - by Ramon Wilson

Click on drawings to download - for personal use only.


Done at the same time as the back plates the basic front housing blocks were milled square and brought to dimension +1mm on all faces. First op was to bore the housing for the main bearing, turn the outer diameter register to a nice slip fit into the case - The housings were turned to .005mm down - well as near as I could tell using tele-gauges - which will probably expand the outer slightly when the bearing is pressed in so they should have a nice snap fit. The inner 10mm bore was drilled, then bored before reaming to maximize concentricity.


A chunky fixture was turned up to hold them for turning/milling the outer profiles.


Thinking ahead too quick, this one was roughed before I realized there was a prior op to do. 


Which was to mill the internal lightening pockets... (Not exactly essential, these are cast in to the original die casting so they were put in for the sake of replication).


First stage complete ready for those front profiles.


This is one of the two Elites. The Mk3 has a single taper back to the face


The set up to mill the Elite Mk2. This is the first real use of the dividing head as a 'rotary table' in shaping.


Initial roughing with a 6mm FC3.


Final cuts with a 3mm with the corners radiused by hand on the offhand grinder.


See part one here  part two  part three  part four  part five  part six  part seven  part eight 

part nine  part 10