About 4 hours on it again, tonight. Decided to finish early and get some sleep!

The center tube has been painted - just need to touch up some matt black inside.

The ring that holds the top set of trusses and attaches to the center tube is done. I started with an 18mm ply ring to which I fitted the threaded inserts and through holes, but I decided to laminate another 9mm ring on the front of it to hide the t-nuts. It's also now painted.

I've fitted the threaded inserts in the top tube and applied resin to the little blocks inside. I drilled a 56mm focuser hole (eventually I want a 2" focuser) and re-resined the exposed hardboard. That was probably the most nerve-wracking bit of the build so far. I used a cheap split-ring hole saw, and kept backing it off to make sure I wasn't putting too much pressure on the tube and letting the teeth do the work. The last thing I wanted to do was split the tube. It went perfectly.

I trimmed a few mm from the secondary mounting block to keep it all within the outline of the mirror. I traced the outline of the top tube on a board and drew a line between opposite corners to find the center. I then drew a circle of diameter equal to the internal distance from face to face. Drawing lines parallel to the outside, I defined the internal 12 segment profile. In the center I drilled a 5mm hole and left the drill bit in. I slid the focuser mount attached to the steel rule onto the drill bit and picked two faces to which I would attach the steel rule. I tapped in a couple of pins and bent and captured the steel rule between them, then read off the measurements for each. The first steel rule I used snapped when I was bending the acute angle for the tabs, so I picked up another (slightly thicker, unfortunately) and started again. I was 1.5mm off center with the first so did the maths and drilled, heated and bent the next one on my camping rocket stove. I should have drilled the holes in the lugs first, but I reckon I can do it... I'll post a picture of that process! I appear to be ignoring 'offset'. I'm thinking that anything can be shimmed, tweaked, etc... so I'm just going for it.

So, left to do now:

- attach secondary to its mount

- measure, drill and test fit the secondary mount in the top tube

- make a mounting plate for the focuser and test fit

- paint the top tube

- weigh and balance the lot

- calculate and cut trusses, and assemble

- make a dobs stand