Further progress in the shop.

June 7, 2010 at 12:26 pm | Posted in Uncategorized | 1 Comment
Tags: machining, steam

The Stuart No. 1 is progressing nicely. I finished drilling the upper cylinder head yesterday. A photo:

The spigot in the center needs to be taken off. I loctited the head to the cylinder, and mounted the rig in the mill on a rotary table. I drilled both with the tap drill for 2BA. After drilling, I knocked them apart with a hammer and opened the holes in the head out to clearance size. I was then able to clamp them together(using a large kant-twist clamp) and use the head as a tapping guide. Got the studs in perfectly straight. It’s a touch snug, but goes on wonderfully.

With the head off the cylinder:

The head and top of the cylinder where lapped together using clover compound. I applied a few dabs between the two and used the mill to spin the head while I held the cylinder against it. The meeting face has a nice dull sheen.

In this picture you can see the port face:

This engine employs a garden variety d-valve. The steam passages are cast in. I still need to lap the port face to flatten it. I think I will do this before drilling for the steamchest bolts. It’s a pain and a half to get the lapping compound out of the holes.

This shows the lower end of the cylinder. Undrilled for the lower cylinder head. That has to be tackled next, and it’ll be difficult. I removed the chucking spigot prematurely. I’m going to machine out the gland and use it to mount the part to an arbour. Pictures will be forthcoming on that one too.