AstroDesigns

Telescope Transport Devices

T-Frame Telescope Transporter

By Jerry Horne <jdhcaha_tix.netcom.com>
San Jose, CA, June, 1998

As an alternative to the JMI Wheely-Bar, it is possible to easily construct a T-Frame device that serves the same purpose. It allows the user to keep the telescope, such as a LX200, together as one unit and wheel it in and out of the house or garage when it is time to observe providing there are no obstacles more than about half the diameter of the casters.

It basically consists of two pieces of 1-inch square steel tube, fastened together in the shape of a "T" with a wheel caster on each of the three ends. Since the weight of the telescope is at the ends of the "T" , the two bars which make up the T need not be welded together, just bolted together to form a relatively rigid structure. Each of the tripod legs ride in a plastic pipe end cap (together with a table leg rubber carpet cushion) which has been bolted to the T-frame.

The parts list is as follows:

1 - 42-inch length of 1-inch square steel tube (cut from a 4 ft length)
1 - 33-inch length of 1-inch square steel tube (cut from a 4 ft length)
3 - 2 * inch rubber caster wheels (with 3/8 inch bolt tops)
3 - 1 * inch rubber cushions (e.g. used under table legs to protect floors)
2 - 4" x 4" T-shaped mending plates
7 - 2" x 3/8 bolts,
10 - 3/8" nuts
3 - 3 inch ABS plastic end caps

Total Cost - approximately $50 (much less if you can get the steel as scrap)

Tools required:

Hacksaw
Drill and assorted drill bits

Cut the square steel tube to the correct lengths. Place the shorter tube in the middle of the longer one, and mark the drill holes using the T mending plate holes. Drill the holes and attach one T-plate on top and one T-plate on the bottom using four of the 3/8 inch bolts.

Drill the holes for the caster wheels, 1 inch end from each end of the T-frame and attach the caster wheels with the 3/8 inch nuts. Drill a hole in the center of each plastic end cap and the rubber cushion. Carefully measure the distance to and from each tripod leg and drill a hole near the end of the T-Frame so that each tripod leg fits in the center of the plastic end cap when it is mounted on the T-Frame. Mount the rubber cushion in the plastic end cap and on the T-frame with a 3/8 bolt and nut. 

Photos:

-- Assembled T-Frame

assembled T-Frame

-- Close up of the T-Frame connection using the T-plates

close up of T-Frame

-- Close up of the end-cap and wheel caster assembly. 

end cap of T-Frame

I originally had the idea of drilling and tapping an additional hole on each end of the T-Frame, to screw in a stabilizing bolt that would lift the assembly slightly off the ground, but I am not convinced this would be as stable as the tripod sitting on the ground. So I just gently lift each tripod leg off the T-Frame, one at a time, and set it on the ground at the observing site. When observing is finished, I lift each leg in turn back on the T-frame, then wheel the telescope back in the house. In any case, adding such a bolt to each end of the T-Frame would be relatively straightforward.

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