Testing a 6" f5 reflector.

Last night I was able to set up the fork assembly on a stool to use it. 

Observations:

1. The focuser is very fussy; probably because using a slow focuser in a fast scope. 
2. Plywood forks tend to 'ring' from any movement. This results in a lot of jiggling. MDF would be a better choice of material. Tapered geometry would help. Buttresses would increase stiffness.
3. Star images are 'splattered,' with no clear coma or diffraction spikes; may be combination of curved vanes and collimation error.
4. At 188x stars show as pale round blobs, not pinpoint; this would be the result of the spherical mirror.

Overall, the design is good for wide views, like nebulae etc. Planetary detail and star resolution would have limited usefulness. 

I'll shorten the height of the forks later to reduce vibration.

Tripod thoughts. 

I will also be plagued with vibration issues in the tripod legs. MDF is not a good option.

A possible solution is to extend the center post further down and lock the legs with a plate bolted to the rod. This will reduce twisting and longitudinal flex. It can also serve as a shelf.

Add wide blocking to the sides of the legs at the attachment point, glued to the legs. 

I can add a 2" horizontal member to the top and bottom of the legs like an I-beam.