After seeing the excellent work of Chris (scopemankit) with his 10 inch travel scope I decided to give an 8 inch version a go, but made out of wood (I don't have the metalwork skills/tools). Mine is an attempted amalgam of Chris' ideas and those of Ross Sacket with his pieces of telescopic artwork (http://stardazed.com/index.html). However, mine just does not have the finesse of both of these terrific scope builders.
Where possible, all materials and the mirror are secondhand and/or have been sitting around the house - wood includes exterior ply, maple, walnut and jarrah, and the arm is from a broken kayak paddle. The only new items are the Kineoptics focuser (the crayford I had was too heavy), some collimation springs from the hardware store, pulley and a lazy susan bearing. I bought the spider from the IIS classifieds (thanks PhilW).
It's nowhere near perfect, but seems to hold collimation reasonably well (for me), even after dismantling and re-building which only takes a few minutes. I did go without the light baffle for a while but eventually added it - and of course it makes a difference in the backyard with stray light from my daughter who stays up too late reading... One day, I intend to make a smaller spider/secondary arrangement like Chris and Ross Sacket have with their scopes.
Total weight is 11kg including 1.5 kg of counterweights in the mirror box.
Anyway, just thought I'd have a go at a scope and also say thanks to our inspiring telescope makers. And, it's been fun to make, tweak and get frustrated with!
Yes, Chris, I need the bungy cord and pulley as an altitude counterweight/tensioner, along with the internal counterweights. I did underestimate the pivot point height but was also stuck with the materials I had at hand, plus I had already pinned and glued the side arm and rocker support...
That looks fantastic! How do you find the stability with the single pole design?
Rod.
Thanks Rod
There is a little vibration which takes 2-3 seconds to settle and is noticeable at higher powers. I can also just touch the pole to damp it down more quickly. Otherwise seems fine.
I just had a second, closer look at your new scope.
I must say, WOW!
Great idea with the light baffel/shield on the sec. cage. And a double wammy with the curved spider! I really like the echo of shapes. Organic. Sexy.
Any chance of some pics of it in stow mode?
I'm still to get my head around the use of aluminium for the altitude bearing surface. Is it riding on Teflon? I'm guessing it must work well, how do you find it? Nice work on bending & fixing it. Was it tricky to get the right matching of the centres with the height of the bearing/bearing pad?
I just had a second, closer look at your new scope.
I must say, WOW!
Great idea with the light baffel/shield on the sec. cage. And a double wammy with the curved spider! I really like the echo of shapes. Organic. Sexy.
Any chance of some pics of it in stow mode?
I'm still to get my head around the use of aluminium for the altitude bearing surface. Is it riding on Teflon? I'm guessing it must work well, how do you find it? Nice work on bending & fixing it. Was it tricky to get the right matching of the centres with the height of the bearing/bearing pad?
Cheers,
Mental.
Hi Alex
Thanks for the comments. Here are a couple of shots of the dob collapsed - the one with the dog for scale.
The aluminium on the trunnion seems to work quite well. I chose it, partly because it's what I had at hand and also after seeing what Chris had done with his scope (http://www.flickr.com/photos/38295849@N04/).
I bent the aluminium by hand to a slightly larger radius (knowing I couldn't get it to an accurate shape) then had to pull, clamp, curse and screw it down. Under tension, it creates something close to an arc - it's not perfect but it's ok. In hindsight, I probably should have made a jig to bend it properly, or taken it to a metalworking shop but I was getting impatient.
The aluminium strip, which I polished using a light cutting compound on a bench buffer, is quite smooth in movement. It sits on a couple of furniture sliders. On the other side, I've used a carriage bolt passing through a skateboard bearing.
Matching the centres wasn't too hard - a bit of guesstimation of the amount to subtract from the altitude radius.
Where's the focuser? and how is the performance? have you taken any pics with it? Sry for the staright away question... A great scope!! Just really curiouse about it
Where's the focuser? and how is the performance? have you taken any pics with it? Sry for the staright away question... A great scope!! Just really curiouse about it
Thanks,
Tony
Hi Tony - thanks. The scope "seems" to work ok - well, at least for me. And, I can't tell you about how it goes for photos as I don't do any astrophotography. Oh yes, you can see the (helical) focuser in the last photo in my first post.
ahh thanks for clearing that up andrew... I see it now.. I probably missed it because I was expecting the usual one that comes stock with other scopes( sry not good with terminology)...
) and the fact that it genuinely looks very, very nice.
