$170 saved!

[Darkplague]

Since my 16" mirror from Mr. Suchting is almost ready to be shipped out to me,
I thought I had better get a hurry on with some of the components for my truss dob ready. I thought long and hard about buying a spider, but at around $170, I couldnt bring myself to spend this on what is effectively about $2 worth of sheet steel.

So here is the spider I whipped up at work, cost to me = zero!!

I am pleased with how it turned out, it is all stainess steel also, so should help keep the rust away. There is roughly ,on and off, about 5 hours of work involved in the making side of things, but since I did it in work time it didnt really matter :P

[AstroJunk]

I hope your boss doesn't read this forum!

[cjmarsh81]

That looks like a mighty big spider. Well done.

[Darkplague]

I have a secondary cage question.

When building the 2 secondary cage wooden rings, is there really a need to countersink the ends of the aluminum tubes into the wood? Does anyone have an opinion on this??

[Lester]

Thats the way Mark.

[AstroJunk]

David Kriege from obsession says yes, and I would tend to believe him - he does build a few. I'm sure that you could get away with it, but its that attention to detail that makes the difference in the end.

[h0ughy]

This is your employer speaking, your docked 170 dollars this pay Mr plague! Nice job!

[janoskiss]

Mate, you're true blue. Spoken like a real Australian! :rofl: You're the foundation on which our great democracy is built. :lol: Superb job on that spider!

[mikey7]

Great job onthe spider, feels great to save the bucks does'nt it.

I just finished my secondary using Kriege's book as a reference and the couple of mills of countersink seem to make the secondary more solid. I toyed with the idea of not countersinking but now I'm glad I did. Just take it slow with the drilling, its really easy to go too deep. Countersink first then drill out the wood for the bolt. By the way I ordered tube inserts from Obsession telescopes (http://www.obsessiontelescopes.com/ATM_parts/index.html), cant recomend them enough.

Adios
Mike

[Darkplague]

Thanks for the comments guys!

After reading Mikeys post, I will definitely countersink them then.

The reason I hesitated was that to drill them nice and square, I would have to smuggle them in to work on their drill press.

No easy task considering their size.

[leon]

You would have to wonder, why is sheet metel so expensive. :P

If your handy you can safe heaps, and the finished product is probably better, and stronger, than the bought version.

[Phil]

Its great when people like us can make stuff and save a lot of money.
As we all no astronomy is not cheap .
Phil H