A Stuart Williamson build

[Jasonb]

I don't think there is meant to be a spigot on the top of the flange. just flat. Not the best positioning of the 9/32" dimension lines which are all that is above the surface.

[Sanjay F]

Ha ..., yes, I can see it now, you're right, bad drawing and bad interpretation on my part!   

I guess I have an added feature with an 'improved' seal - it made positioning the flange at the 30 degree angle easier as I could rotate it into the correct position 

[Michael S.]

I must also say that the column with base plate and top part looks very fascinatingly good.

[Sanjay F]

Thanks Michael

I thought I'd do a test fit of the cylinder in its home and gosh things are very snug indeed. I will be cutting the studs to length but the gap between the valve chest nuts and the column looks VERY tight. The bottom pair are screws and I need to drill 2 access holes in the column - I wasn't going to do this, but given the tight space and ease of setting the timing I think I will

The use of 7BA half nuts may help, if not the valve chest cover could be thinned and there's always the option of losing the raised bosses on the valve chest.........step at a time and hopefully one thing will work out!

[Sanjay F]

Day of off work has proved fruitful. I managed to get the column to fit correctly and clear the valve chest nuts by making some 7BA 1/2 nuts from 8BA ones - fiddly 

This still didn't give me enough clearance and the column was getting pushed backwards and not sitting correctly, so I thinned the valve chest cover and reduce the little bosses on it until it all fitted together. Then onto milling the clearances spaces on the top of the column for the eccentric and crank

With the column now bolted to the base I started to put the engine together and this one is going to take a fair amount of fettling. The crosshead guides are hitting the spacers at the top of the stroke and it feels like the piston (or something) is hitting at the bottom of the stroke.

Time to call it day for today!

[Jasonb]

Check you have the piston rod screwed all the way into the crosshead clevis. It would be usual for all the 7BA thread to go in so the clevis butts up against the full 1/8" dia part of the rod. This would stop the piston from hitting the bottom.