So you use turn buckles to tension.
I used 3/4" aluminum conduit as poles and set couplings into the mirror box. I tension the strings by unscrewing, backing out the conduit poles. It is time consuming.
That is what I am exploring. Otherwise it works great.
Based on the emerging development of strings scopes back when I built this scope (2006) and influenced by some of the pioneering ATM'ers building string dobs at the time (most from our Rose City Astronomers Club in Portland, OR: most notably, Dan Gray) turn buckles were seen as the way to tension the strings, so I originally went with that design. But I quickly realized it would be easier to deal with fixed length strings and adjustable poles, so ended up transitioning to that design (not shown in the photos on my original build).
I had a machine shop bore holes through some bolts that fit within the pole then attached a screw and nut to hold them in place, though they have a little play in them which is a good thing as it helps when fitting into the secondary pole/string holders. The nut is jammed in a plastic pipe fitting which fit in a hole in the face of my mirror box. And, the secondary pole/string holders was also redesigned along the way with a custom part machined by a friend.
Yes, it does take a couple of minutes to screw the 3 poles all the way through the bolt so you have enough clearance to place the secondary on top of the poles, and another couple of minutes to unscrew the poles until your strings come into tension. I leave the strings attached when disassembled. I've never thought it too time consuming to setup, especially when watching others dealing with their EIGHT poles and SIXTEEN connectors.
Edited by David N, 06 August 2020 - 06:02 PM.