80mm long focal length refractor

[savarin]

I took very fine cuts so as not to over stress the tool bit.
Sanding with differing grades of wet and dry soaked with WD40.
Down through the grits starting at 240, 800, 1200.
Then tripoli on a sisal or hard denim buff depending on how deep the remaining scratches are then white rouge/alluminium polish on a soft cloth buff.
It takes way too much time and I am totally over it the trouble is once you polish one item all the others have to be done else it looks terrible.

 

[savarin]

I have decided three bolts on the plate and one bolt and one peg on the boss.
Drilled and tapped one bracket and the plate so far.
I will make a short pointed peg to mark the boss for that hole and a 2mm point to mark for the bolt threaded hole.
It hurts when you want to get going but other things encroach on your time preventing you from ploughing ahead.

 

[savarin]

A small pointed rod to find the spot for the hole


replaced with a peg once the boss has been drilled

but look at all those scratches I now have to polish back out.

 

[savarin]

Brackets installed along with a forked front tube support.

First tests appear to have solved the flexure in the plate.
Next I wanted a pair of three hole brackets so I can fix a carry handle between the,
The first set I made from some 10mm scraps and rounded the ends in the lathe by bolting them to a long handle, pivoting off a 6mm rod in the tool post so I could control the rounding process.
Its looks as dangerous as hell but its only aluminium and by only taking small cuts it was extremely controllable, way easier than I expected.

And produced this, nicely rounded off.

However the 10mm brackets looked so out of proportion I went back and redid them again in 6mm scrap.
Then I bolted the pair to the wonderfull vertical slide and milled out the sides to reduce the amount of filing required.

Not brilliant but way less filing required.

and ended up with these.

Being scrap they need a heap of sanding on the faces before ---- yep! you guessed it, more polishing.

 

[rwm]

Brilliant work with your new slide. That fixturing plate with holes is a great idea. I need to do that.
Robert

 

[savarin]

Got the handle brackets polished


Used a chunk of cast to make a screwed cap


To fit the finder scope

I did polish it but there are some shrink marks in the centre so I think its going to end up black.

Started on the handle by knurling the centre, this will bolt onto the two brackets above

Now I need to move the tail stock over to turn the two ends in a taper. I've never done this before so it will be a bit of a learning experience.

 

[savarin]

This went easier than I thought it would, a pleasant surprise.


Just have to drill some holes to fit it here.
.

This thing looks more complicated every day, I wonder if I will ever finish it?

 

[brino]

Stellar! (pun intended)

-brino

 

[savarin]

thanks

 

[savarin]

More bits.
I made a brass shield to go round the azimuth gear. It looked great.
BUT! I,D.10T moment, the telescope couldnt be removed from the support structure.
Oh well, back to the drawing board and design one thats easily removable with captured screws so they wont be lost when dropped in the dark.
I came up with this, some 12mm plate with a section milled out (sorry, no pics) with one end rounded the same way I did the auxiliary holders. (A bit scary but doable)
Then mounted to a wooden backing plate bolted to the face plate.
The centre cut out then a flange cut.
A bit of filing to clean up and test fit.



looks ok, the brass sheet will be fixed to the rounded part reaching down to the milled out section.
Just looking at it now I think if the holes the two knurled screws go through were elongated vertically it would allow the shield to tilt away from the gear allowing the scope to clear the shield.
We will see.