|The Weightless Oak Mount|
|Here are the plans in Acrobat 5 format: Oak Mount Plans|
This is the outside of the mount case. It holds everything but the legs.
This is the case's inside bottom part. The foam is camping mats from Wal-Mart. The top contains the tripod tray. The items in the bottom right are wrapped in padding before closing the case.
|This mount was inspired by the
article by Chuck Hards in the October 2000 Sky & Telescope.
Check out his Weightless Woodshop mount article for the details.
I needed a mount for a 'short tube 80' for an impending trip to New Mexico. While I had a large German Equatorial for the C11, it wasn't practical to take on a plane. The mount was built in a week and a half in the garage. All parts were purchased at the local hardware stores (Lowe's, Home Depot and Ace) and no special Teflon or Formica was used. Where possible the hardware is stainless steel.
The Formica was left over from making some counters a few years ago. The bearings are furniture sliders from Ace hardware (their brand was the only ones that had Teflon and were smooth enough)
The unusual thing about this mount is that there is no counter weight to offset the weight of the scope.. The bottom bearing acts as a virtual counter weight.
The PVC trunnions are adjustable and allow balance with any of my current eyepieces (up to a 2" diagonal with a 22 Nagler and a little room to spare). They are 3" to 2" reducers which I added a oak core.
The mount was finished a day before the trip. The legs were packed in a golf bag (with plenty of padding) and the rest was put into a hard shell suitcase. If I has any room left I would bring a change of cloths.
The scope was carry-on.
I added a cradle to prevent a scope crash, especially at public star parties. Originally I was going to pad the bolt, but that was tacky.
I chose Oak because MDF and the humidity of coastal Florida don't mix well - actually they do mix well and that's the problem. Besides, I LIKE Oak!
Leg Travel Brace & Parts Holder - I was looking for a way to hold the legs together during traveling as well as a way to keep the loose parts and a few spares handy. The result was some 4" diameter PVC threaded at one end with a screw-in cap and a rounded cap glued on the other. Three holes were drilled in it and carriage bolts stick out that go into the same holes on the legs that the tray uses when set up. A few stick-on rubber bumper pads were added to cushion the legs from rubbing against the PVC. The 'L' shaped bottom bearing even fits in here as does a trash bag for unexpected rain..
Rigel Quick Finder Support - May 2001 - The double-sided tape holding the Rigel Quick Finder on was shifting during the night. I thought about making a plate for it when I made the original tube ring braces but ran out of time. The new brace with the Quick Finder plate is on the photo (left) and works great.
The plate was added by drilling three 1/4" holes in the top of the tube ring brace and matching holes in the bottom of the plate. Wooden pegs and urethane glue hold it together. The plate also rests on the flat tops of the tube rings (the part that protrudes over the rings) and makes it quite stable.
The plate was added to the left side because I usually use my right eye with the finder and this prevents the diagonal/eyepiece from being in the way.
For the record, I still prefer the Telrad but it was too big for this little scope.
Solar Filter Addition - June 2001 - While at the Spring Chiefland Star Party Thomas Swann was kind enough to give me a piece of Baader Solar film for the Megrez. The oak cell for the film came out better than I had expected.
Halloween 2001 - I set up the Megrez on Halloween night, which was conveniently timed with a full moon. Kids, parents, ghosts and goblins were lined up most of the night to see the moon. The telescope views were a bigger hit than the candy. Lots of 'ohhhh, ahhhhh, wowwws' - and the kids liked it too. Next year I'll make handouts to let them know where the telescopes will be set up in the weeks following Halloween. Very cool.
Mount case - May 2002 - The pieces of the mount really needed a case to keep them together and protect them. The case shell was cut and glued up in one evening. The next night the lid was cut off and the dividers were added. It isn't too pretty (compared to the eyepiece case), but it does the job.
For plans to the case go here: Case Plans
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