Constructing a dob

Those secondary holders look the business Michael.

I had a problem with the method I was using, i.e. clamping onto the ply. The wood just wasn't particularly strong and the bottom two layers above one of the clamps has split already so I may be ordering a set of these if it gets worse after all.

Just wondering, where did you manage to find Kydex? Turns out the felt I got is great for lining the mirror box and baffles but it's a pain on the secondary cage.

Thanks,

Trevor

I got mine from Meridian Telescopes www.meridiantelescopes.com/

Very nicely made Michael,
One thing, is the part that came off, unser one of the clamps, if so you now have very slightly differing heights for the poles now.

The formica can be got at B&Q, although not the small size you want though, I do have some here if you want it.
As for a sling, try a local scrap yard.

The piece that flaked off is tiny, fractions of a mm in thickness. Well within the tolerences of the accuracy of cutting the tube.

What size sheet of formica did you get?

Its counter top formica, it's about 1 inch thick, so I on thinking about it again
I'm not sure its much good to you as its quite heavy.

Some of the Hardware shops - Woodies, Homebase and even Dunnes stock Luggage straps about 50mm wide complete with plug in type clips on the ends. I have also seen twin packs of 50mm by about 750mm webbing with Velcro on both ends in Hombase and Woodies . This should easily take a few stone in weight.

For really tough webbing however try the mountaineering Dept of the Great Outdoors- they used to sell webbing by the meter quite cheaply it is actually be much sturdier than a car seat belt and very weather proof - I use it as a weight belt for scuba, I bought it about 8 years ago and despite frequent immension in salt water carrying a couple of stone of lead its as good as new. Their scuba dept would carry pre-cut lengths of webbing but its not as strong and its very much more expensive.

The real heavy stuff can be cut with a new blade on a Stanley type knife and then to prevent any unravelling/ fraying of the cut ends apply the flame from a cigarette lighter to burn-off frays and seal it- the heavy mountaineering stuff appears to be flame-proof so this is probably the most difficult part.

If you need to stich it get heavy nylon thread (not cotton) also get a 'bodkin' type needle- this is a heavy duty type needle with a wide eye. Double the thread first then feed it through the bodkin eye so that you are using 4 threads at a time in the stich. You may need to use a long nose pliers to pull the needle through the webbing each time. Alternatively if you know any shoe repair shops (there dont seem to be Cobblers around any more) they may have the right gear to stich it for you.

Luggage straps won't do I'm afraid. I need something which is not elastic at all. Thanks for the suggestions though.

After a few hours work on the dob this evening, below is an image I took of the completed secondary cage:

www.astroshot.com/Dob/16.jpg

Its looking good Michael.