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New project


Kaptain Klevtsov
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Very "Bling" Pedal bin!!

Colder, much colder.

Watch this space. Its loosely based on a website I saw entitled "how to spend all your money on making a telescope", it involves some mirrors and loads of swearing. Great fun though and if the welding works it could actually work!

Captain Chaos

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How much twist has the cage got? I'de consider some diagonal cross beams to stop torque etc. What diameter is it CC? Looks great. Orion Optics sell spiders if you email them. the double O varitey if you prefer or the T type. Who are you buying your mirrors from? What focal length are you aiming for? I'de love to have a go making my own scope :)

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Its not a Dob, its going on the EQ mount hence the lightweight construction. Its to fit a set of 12" f/5.3 Orion mirrors that a very kind guy called Tom sold to me.

The cross bracing will go in after I find the balance point with the mirror cell assembly fitted, then a further hexagon goes in at the balance point, then stiffening diagonal braces each side of that.

Captain Chaos

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The new pier has the mak sat on it at the moment for some more temperature equalisation than I've done in the past. The clouds look like a possible Saturn snap might be in order tonight.

I am currently pondering over the primary mirror centreing issue, and what happens if I try to drive a woodscrew through it. The two aluminium bars that the mirror sits on need to be attached to the mirror somehow and the whole collywobbler fixed to the 'scope frame.

Also on tonight's agenda is the secondary mirror mount arrangement. These design issues will take at least four pints of thinking about and that's on top of my imaging foray. It could be a busy night.

Captain Chaos

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Well the clouds rolled in again and my first bash at a spider seems potentially good. Ran out of MIG wire for the frame so that stopped me from more setting things on fire. All that and still only two Stellas even with the lovely evening that we had. I must be slipping.

Next one is where to put the focusser / what it looks like / is it electric etc. Dimensional and fiscal decisions all to be balanced out.

Best position for in and out focus, bearing in mind Barlows and focal reducers = 1 1/2 pints to 3 pints.

Crayford/rack and pinion = 0 pints really but better round up to one.

Electric / manual operation = ditto

So I need another five pints before i can say that I have considered the design parameters sufficiently to make a decision.

Updates to follow

Captain Chaos

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That would be really really good Arthur, thanks for that.

Spider vane design I think will be like this http://www.rfroyce.com/spidrunq.htm so that I can arrange for it to adjust up and down along two of the frame rails along with the focusser. This should allow me to use focal reducers, Barlows etc. which I can't with the Skywatcher as it hasn't got enough in focus travel. The adjustment will allow me to move the secondary as far along the tube as possible to grab as much of the light cone as possible, otherwise there will be more light spilt past it than is ideal.

Yesterday I managed to get the collimation frame set up including quick release knobs to detach it. I have a laser which I clamped onto the frame and had a play with the colliknobs. It turns out its easy to aim the laser accurately and I can hit a small nail at the other end of the garage. I had the older boy pointing which way to move it and we got it bang on. Quite pleased as I thought that it might be very coarse in adjustment. One modification which was necessary was to remove the springs and put nuts behind the support frame. Now I loosen the knob, turn the nut and retighten the knob. With only the spring holding the mirror up it was too sloppy. I also got the balance point worked out so that when I get more welding wire I can fit the mounting hexagon and the diagonal bracing. The mirror is currently sat on a bead of silicon which should hold it to the collimating frame and when that has cured there will be eight small screws as well for added security.

More to follow, this has to be finished before the dark comes back as I'm dying to have a go with it.

Captain Chaos

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