custom built tripod for Vixen Porta
Posted 16 February 2010 - 10:08 PM
clamping to head
leg clamp & foot detail
lower leg stop
wire lanyard spreader with split ring key holder
Not crazy about the wire spreader, considering a more rigid structure that opens the legs in a more controlled manner. Either that, or maybe run the wire lanyard from leg to leg instead of to a central ring.
Feels solid. Waiting for some weather to try it out with the TV 102. Thinking about an EP caddy next ...
Posted 17 February 2010 - 06:45 AM
I was just looking at my Voyager mount last night and thinking the same thing.
Due to the taper do the legs always have to be fully extended?
Posted 17 February 2010 - 10:24 AM
The leg clamps are sliced out of a 2-1/2" square stainless tube with 1/8" wall thickness. That 1/8" turns out to be plenty strong for the threads of the clamping screws, which seat on a small piece of folded aluminum plate to distribute the pressure and protect the legs. The feet are 1/4" aluminum plate glued and screwed to the lower legs, and act as stops when the legs are collapsed.
The upper legs are tapered to allow more meat at the head, and split with a kerf for a few inches to give some flexibility for fit and clamping. The lower legs are straight and can be adjusted to any height. Maximum leg length is 55". The lower legs also have an aluminum disc stop at the top that keeps them from sliding out of the clamps when adjusting the height.
The T-handles, T-nuts (at the top of the top legs) and wire lanyard are from McMaster Carr. The lanyard eye loops are stainless, from a boating supply house. The lanyard ring is a chrome-plated split ring key holder. :]
The sassafras is light weight, reasonably stiff and makes the shop smell like root beer.
Posted 17 February 2010 - 12:15 PM
the feet and the leg clamps are cool too! mcgyver would be extremely proud
Posted 18 February 2010 - 12:16 AM
Posted 19 February 2010 - 09:48 PM
The Bad News: The Porta Azimuth control fails in one direction, apparently due to the weight of the OTA with finder and hand grenade EPs. The offset arm apparently induces some torque that the AZ slow motion control can't overcome. Altitude works perfectly.
More Good News: I now have a Polaris mount that will run as a Alt/Az or manual GEM or tracking GEM, and the custom tripod legs will bolt right on.
Anybody interested in a Vixen Porta?