Got the bottom tube painted with £shop matt black - it's more a dull satin compared with the blackboard paint on the inside, but looking good. Few drips and the surface wasn't totally prep'd but I don't care too much.

Got the threaded inserts for the truss rods superglued into lower end of the centre tube, having made another jig for accurately placing drilling the holes. Also reinforced the wedges with a couple of screws each from inside. Also got an 18mm ply ring traced and cut for the top end (to let me split the scope in two) and coated it in resin.

Got the little internal blocks cut, glued and clamped in place for the top tube threaded inserts to bite into.

Then set to work on the secondary mount. I already had the 45deg mount with threaded rod so just a small cube of wood a la Stellafane mount. Drilled a steel ruler and epoxied a penny washer to it to keep the mating surface flat. Despite my best efforts, neither of the holes through the block were perfectly square, but I should be able to compensate later.

The silicone sealant I have says not to use on brass, but that's what my secondary mount is made of. I may mix some JB weld and spread it over the plate with a threaded bolt to give the silicone a keyed surface to adhere to that's not brass.

Good progress for one night.

Next on the list:

- threaded inserts in the top tube

- drill focuser hole

- test fit the secondary mount

- mount secondary mirror

- fit threaded inserts in the ring

- drill bolt holes through the ring and centre tube top-end 'lugs'

- sand the ring flush to the center tube

- paint the top and centre tubes and ring

Then:

- assemble, weight/measure and calculate truss lengths

I've got 1/2" x 1.6mm M6 rubber washers coming - one under each truss to let me elongate the holes in the trusses in order to align the tubes accurately without them shifting. It'll save the paintwork, too. ;)

But there are soooo many things that can still go wrong. I may need to use a different silicone for the primary. How well the superglue is going to hold the threaded inserts is a big unknown. Getting the tubes aligned when I fit the truss rods may be a nightmare. Etc.