Hi Glenn,
Thansk very much. I actually used very primitive methods putting the tube togeter. Having learnt how to collimate these mass production newts like Quattro 10, I knew the only thing need be pricise would be optical axis of mirrors which must be aligned. I used a ruler to find out rough distances of seocndary mirror and re-used the mounting rings and plates of the scope. These were pretty stable. I could add another dove plate for more precisions but to save weight I just used fence bars. Once these three piece were put together I could easily put more bars around. I only used a hammer and a drill, and no joints were needed at all. These can only be done with metal bars but not for cabon tubes. One problem was to work out angles to fit flattened bar ends. After a few trials it would be easy. Once the bottom part for primary mirror were done, I used flat tops of pool fence for focusing unit for better stability. Some trial and errors would be needed to adjust levelness of finished top ring. It's important to measure all distances between focus plates etc. For better mounting of primary mirror I used some metal sheets around the base (I could have cut off some bottom parts of the original tube) which also added a bit weight. To be honest, in the end I made the scope so much more accurate in every aspect than original factory setup. All mass production scopes would need precise tuning. I find literally nothing were precisely put together with Skywatcher tubes. Centre dots on primary mirrors were definitely off on all three scope I had. Secondary mirror positions were never accurate. However, optical qualities of mirrors seemed to be ok, which means there scopes can be turned into very cost effective equipment.
John
Quote:
Originally Posted by gb44
Great work John.
With regard to carbon fibre joints I have a suggestion. I used this method for aluminium tube. Get dowel to fit inside your choice of tube. Slit the dowel to accept a piece of flat bar to protrude from the end (aluminium or steel). I presume you aligned the rings of your truss tube with a laser - once the tube mounting holes are in the rings the truss tubes can be made and glued up in exactly the right place. Glue the bar into the dowel and into the tube with epoxy glue.
Cheers
GlennB
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