We have a 4 1/2″ reflector telescope (an Orion StarQuest) which is on a Dobson mount. I got fed up constantly having to reposition the scope while watching e.g. Jupiter, as what I was watching moved out of view. I decided I needed an equatorial mount with a motor drive, and started looking around to see if I could find a mount that would fit the StarQuest scope, but the mounts I found were all very expensive. In the end, I bought a Celestron 127EQ (see Figure 2) which came complete with a German Equatorial mount, for the princely sum of $116 on Amazon.I also ordered a Celestron AstroMaster motor drive (Figure 1), and a Celestron 93625 T adapter and a Fotodex T adapter mounting ring that would allow me to attach my Canon Digital Rebel XSi to either scope (they both have 1.25″ eyepiece tubes).
After assembling the Celestron and fiddling about playing around and understanding the EQ mount, I realised that the supplied tripod was going to drive me nuts: it wobbled and swayed even if I breathed on it. I tried tightening everything up as much as I could, but it still wobbled – it was far too flimsy.
So I decided to make something a little more sturdy using bits and pieces I had in the garage. Here are the parts I collected:
- 1 Circular piece of 3/4″ thick plywood, diameter 24″ – base board
- 1 Circular piece of 3?4″ thick plywood, diameter 12″ – scope platform
- 1 5ft length of 4″x4″ wood stock – pillar
- 4 shelving brackets
- 4 3″ steel brackets
- 3 screw thread furniture feet
- 3 nuts to fit the feet
- 4 3″ lengths of 2 1/2″x3/4″ wood stock
Find the centre of the 24″ diameter circular base board: drill a pilot hole through the board there. Place the end of the 4″x4″ pillar upright at the centre of the base board, position the four shelving brackets against the sides of the pillar, mark screw hole positions in the base, and then screw the brackets in place on the base board.
Remove the pillar from the base board, turn the board upside down, then place the base board on the top of the 4″x4″. Drive a long screw through the board, into the 4″x4″, then drill a couple more holes nearby, and drive long screws into those, too.
Turn the board and pillar right way up, carefully supporting the pillar. Now attach the brackets to the pillar with screws, and tighten all screws very tight.
Take the four 3″ steel brackets and attach each to each of the 3″ lengths of wood stock with screws. Then loosely attach each combination to each side of the top of the pillar so that they are centred and level. These will act as spacers so that one can gain access to the nut at the centre of the EQ mount to tighten it.
Using a jigsaw, cut a circular hole in the centre of the scope platform board, of the same diameter as the circular part of the Celestron tripod platform (see Figure 3).
Remove the legs from the Celestron tripod, leaving the platform for the EQ mount, and put the threaded rods and nuts that secured the legs to one side. See Figure 3. Drill a hole through the top of each “spoke” of the platform: these will be used to pass the rods through and tighten the platform to the board.
Place the scope platform board on top of the spacer/brackets, mark and drill pilot holes through the board into the spacers, and screw tightly in place. Then firmly tighten the brackets against the top of the pillar. See Figure 4.
Place the tripod mount on top of the platform, centre it, and carefully mark the positions of the three spoke holes, using an awl. Before drilling through, make sure that the positions are clear on the underside of the board, and wont foul any of the platform supports.
The platform board should be fairly horizontal at this point, but it’s not critical as there will be adjustable feet added to the base board. These will require captive nuts. Turn the whole mount upside down so that it is resting on the scope platform. Using the centre of the base board, and a protractor mark positions for the three feet at 120 degrees from each other, about 2″ in from the edge of the board. Find three nuts that will fit on the screw feet. Using e.g. a Forstner bit, drill large diameter holes just bigger than the diameter of the nuts, part way through the base board. Find a drill just smaller in diameter than the screw thread on the feet, and drill through the centre of the holes to the other side of the board. Test to make sure that the feet than be screwed in and out of the holes. See Figure 6.
Using a two part epoxy, glue the captive nuts into the holes, taking care that the nuts are centred and that no glue gets into the threads. Leave the epoxy to set. See Figure 5.
Sand all surfaces, clean with a rag, and then spray paint your choice of colour. (I had a bunch of Rustoleum Navy Blue indoor/outdoor aerosols left over from another project, so I used those.) Leave to dry well.
Mount the Celestron tripod platform to the scope platform board, using the threaded rods and nuts that came from the tripod. Screw in the three adjustable feet at the bottom of the base board. The platform is now ready to use.
Here is the finished mount (Figure 8) with the PowerSeeker 127EQ attached. There is a minor problem: the counterbalance for the scope touches against the scope board for low inclinations to the horizon. This will simply require the scope board to be reduced in diameter by taking a circular cut around it – but I haven’t bothered since the viewing area is surrounded by high walls anyway.