Sunday, August 23, 2020

started dry-fit

Worked on the Dobsonian base build...

Made the cradle box. Was about to put the carry handle on the top when I realised the screws were too long. Put the shiny handle aside. 

Attached the altitude plates. Followed the directions at Stellafane page. Centre point, 45 degree angle, mounting screws, all pretty easy for the first plate. For the second one, I was worried about getting it in the exact same position. I used my lovely long level to help.

Ready to wrap around the Edmund OTA...

Started work on the rocker box, again using the pieces cut as per the Stellafane design. Oops. Ran into a few issues.

First problem is that the first side plate was not square. So it was running at a funny angle for the altitude bearing. Of course, when the base is affixed, I can apply some outward bias to square it up. And I can put a spacer at the front (6½" long)...

[ed: Oh. On re-examining the Stellafane images, I see they have little triangular pieces near the top. Right! I'll do that. Ensure those pieces are square and it will all be good.]

The second problem was very strange but easily fixed. The back (front?) board is too wide. I must have measured wrong. It looks about a ½" too wide. I'll cut that down later... 

That will mean the handle-opening is offset but that's a minor concern.

That the cradle box is just under 8" in width, the reinforcement piece for the centre board is too long.

Considered adding the bottom plate but decided to wait until I have the reinforcement piece installed.

While testing the motion and movement of the cradle in the box, I wondered about putting the guides on the inside but there are a lot of collision and interference points. Still, it's got me a'wonderin'.

Everything was assembled with pre-drilled screws, dry-fit. I'll glue the wood later.

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