Hi Achim, Nice to hear from you, thanks for your kind comments
It's been time consuming and a bit tedious at times but the end result has been well worth the effort I feel.
I was hoping to have the flywheel in place today but one of those streaming eyes and nose summer colds has set in which tends to get in the way. Whatever I do now have the crankshaft finished and also one cover board ready to fit with the other not far behind
Re those eccentrics - you may recall I decided not to split them as per full size due to the difficulty of tightening the bolts. However the discussion at the time lead me to think I should at least try to give that impression.
This was how they were when first done
I don't have any pics of the op but first off was to hold the eccentric on a mandrel in the lathe and setting the two flat faces vertical a line was scribed using a sharp pointed tool on it's side across the centre line.
(Edit) The lathe spindle was locked on the bull wheel then rotated through 90 degrees to scribe the line) The corners in the cut out were then filed to allow a 5BA nut to sit inside. It was then set up on the mill and two holes drilled through the rim to break through into the cut out.
A bolt was threaded into a nut to give the right amount of protrusion and loctited in place. The threaded part was cut off below the nut leaving about 5mm. This was then wiggled into the hole until the nut sat flat against the face. In order to acheive this some of the lower threaded part had to be filed away. Once satisfied the nut was held with a drop of cyano. As this was not likely to hold totally secure the through holes were then back filled with JB Weld making sure it was well poked down the hole to surround the threaded portion.
The eccentrics were finally set in position today - the shaft had been scribed with two lines at the inlet and exhaust lead angles relative to the dowel hole which would secure the crank web. You can just make out the lines on shaft and eccentric in this pic. At this stage the crank web has yet to Loctited in position
The crank pin was turned from En1a free cutting MS and the banjo oiler boss from brass. Must admit tapping those three 12BA holes with two taps that to be fair have definitely seen better days made for a few anxious moments.
The black ring at the far side is the closing ring for the inner cover board hub parts
Well that's as far as progress got today - hopefully it will all be back in place tomorrow.
Hope that explains the 'dummy' eccentrics ok Dave and Chris
Time for a hot toddy and a warm bed me thinks
That's it then for tonight, regards for now - Tug
