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Wedge Stabilizer Design

by Ed Stewart <stargazera_tskymtn.com>

 Stabilizer General View I put my Meade 7" Maksutov on a wedge and experienced the instability that has long been a problem with fork mounts in the equatorial position. A member of the Meade Advanced Products Users Group (MAPUG), Doc G., has determined by using scientific testing methods that the source of most instability lies in the RA bearings.

 And there is little that can be done about it short of redesigning the entire mounting. My work-around solution is to provide additional support to the overhang of the wedge from the tripod head. This changes the frequency of oscillations and dampens them in about half the normal time. My solution is a very simple to make system comprised of:  

  1. A wooden clamp that attaches to the tripod leg directly under the wedge's overhang.
  2. A thick metal strap that runs along the bottom edge of the wedge to provide pressure points for:
  3. Two 0.5" X 18" all-thread rods that go from the wooden clamp to the ends of the metal strap.

  The result is not only physical support of the weight of the overhanging wedge, but triangular stiffening in two dimensions. The effect is a magnitude increase in stability. I can now focus at 150x where before the shaking was so bad it was impossible to interact with the focusing movements. Painted black, and with black tubing over the threaded rods and with the silvery bolts, the system is "Meade'ish" enough to look factory original. Note: depending on the orientation of your wedge on the tripod head, you may have to have a clamp on two legs with only one rod going to each.
See this at: Chris Vedeler's Page.


Drawings: 

End View

End View 

clamp

 Clamp Top View

Side View

 Side View

 

I believe the design drawings speak for themselves as to construction details except for the ball joints, which are simply shallow depressions drilled into the wood clamp's top surface with a .5" drill bit (about up to the edge of its flutes), and then rounded ends of the rods sit in the depressions--it's very effective since the Baltic Birch plywood I used is so hard. Other wood will probably be OK too just make sure the grain runs at a right angle to the tripod leg. Takes about 2 hours or so to build.

A further thought has occurred to me to use wingnuts instead of the bolts on the top end of the all-thread so a wrench wouldn't be needed to adjust the tension.

  Clamp Close-up   Side View of Wedge & Stabilizer

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