The Giant Binocular

[savarin]

One step forward and two back.
As your knowledge base increases so does your recognition of past inadequacies.
I bolted the two new parts on and found one was higher than the other by around 0.5mm
This led to more checks and I found the two lazy susan bearings were at slightly different heights and cants.
This was due to tiny discrepancies in the welded trusses.
I clamped the bearings to two long straight sections and aligned them as close as I could measure to 90 degrees to the optical axis.



The T shirt hanging on the end is so I dont forget it sticks out and smack my head on it.
Dont ask me how I know that might happen.
I then used different numbers of shims to keep that alignment as I bolted them back up.
The gaps ranged over 1.5mm with some only needing 1 shim and two that needed 4 shims.





I will now do the same with the top cages when I bolt them on.
Then I can check the the two plates the new parts are bolted to are parallel and if they are not I can use the same method of shimming for them.
This has also led to the realisation that the over lock clamps that hold the tube together are not tight enough so I will re visit the captive bolts again to ensure a tight firm clamp. Good job I didn't dump them.
Ahh, I feel better just talking about it. I will feel even better when I get it done.

 

[Downunder Bob]

Charles, your perseverance is amazing. I would not have the patience to do what you do.Just the thought of aligning two rather largeish telescope devices into what becomes a very large binocular. the optical alignment must be very difficult. Yet You just amble along with a bit of shim here and a washer there and make it all work. I'm in awe

Well done old mate.

 

[savarin]

Thanks Bob, I really need the encouragement at present as I'm finding the motivation a bit difficult to come by at the moment.
Silly little things like the diagonal I used as the measurement to bore those new bits was smaller than it should have been.
The new diagonals didnt quite fit so I had to re bore them. Only a thou or two but these are a standard part and they should all be the same dia irrespective of what manufacturer they come from.

 

[Boswell]

Awesome work Savarin. I look forward to every post you make on the Giant Binocular project. And remember 2 steps forward and 1 step back is still forward motion !

 

[rwm]

We are watching keenly. I hope you show some astrophotos at some point!
Robert

 

[savarin]

We are watching keenly. I hope you show some astrophotos at some point!
Robert

Ha Ha, you will have a long wait for that Robert, astrophotography is not on the cards in the foreseeable future.
I see all the hassles my mate has every time he goes out to want to go down that path.
It would be nice but I dont think I will yet.

 

[rwm]

Well then I'll just have to fly down there and look for myself!
R

 

[Downunder Bob]

Thanks Bob, I really need the encouragement at present as I'm finding the motivation a bit difficult to come by at the moment.
Silly little things like the diagonal I used as the measurement to bore those new bits was smaller than it should have been.
The new diagonals didnt quite fit so I had to re bore them. Only a thou or two but these are a standard part and they should all be the same dia irrespective of what manufacturer they come from.

You're welcome, and I know the feeling. I often struggle to put the finesse into the finishing touches of a job,"Hey it works, so what"?

 

[savarin]

The usual story of going back to re-visit a part made earlier that is not good enough.
The four thumb nuts that hold the altitude bearings could not be done up tight enough so I made a different design.
First I turned down some stainless bar from 19mm to 16mm, drilled and tapped an M8x1 thread 25mm long inside.
Then I indexed 3 points around the 19mm part with the air grinder and a small drill.
These marks were then centre popped.



Then I drilled the marks out to 5mm ready for an m6x1 tap.
I started the lathe running in slow, centred the drill on the centre pop mark and holding the bar advanced the crotch centre onto it which rotated the bar but kept the drill on the centre pop mark, then drilled 2/3ds through. rinse and repeat for the other two holes.



I started the tap the same way but turned the chuck by hand till it was too tight to move and completed the tapping in the vice.



Next I made 6 6mm rods threaded M6 at one end and rounded over at the other end using a woodwork router bit.



screwed the arms into the nuts.



and screwed the nuts in place of the original altitude bearing clamp nuts.



Now I can screw the bearing clamps up almost tight enough to lock the altitude in place thus doing away with the disk brakes (but I wont)

 

[silverhawk]

Wow. Just wow.

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