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  Superwedge Modifications  
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Meade's Superwedge Could Be Better
Designed for the LX line of telescopes, Meade's Superwedge is a solid piece of equipment for equatorial (polar) mounting. As with many Meade products though, it's full potential is not realized as shipped from the factory.

Why Modify
The Superwedge leaves a bit to be desired because:
  • the tolerances between surfaces are low leading to innaccurate movements.
  • Meade uses cheap fasteners that lead to noisy and coarse operation and are prone to corrosion.
  • an Allen wrench is always needed to tighten and loosen parts.
The upgrades covered in this document will:
  • quiet the operation of the Superwedge.
  • lead to much more accurate movement and deter corrosion.
  • free you from the use of an Allen wrench.
Where to Buy Parts
Many good hardware stores will have most of what you need. It's best to start gathering the needed parts at your local True Value, ACE, Home Depot, Lowes, or mom n' pop hardware store. For those harder-to-find parts, try McMaster-Carr or Smallparts.com.

Tools needed for my upgrade  Azimuth adjustment thrust bearings  Latitude adjustment thrust bearings  Azimuth adjuster T from back  Azimuth adjuster T from front

List of Parts
There are many things you can do to the Superwedge to improve its performance (because there's a lot to be improved!). You may not want to perform all of the upgrades listed here so you may not need all of these parts.

The lighter text refers to an advanced modification and can be skipped if you only want to perform the simpler modifications.

The last three items in the parts list below are only needed if you decide to perform the advanced modification, replacement of the azimuth thrust assembly (which consists of the azimuth thrust bar, a threaded rod, and jam nuts). Replacement of the azimuth thrust assembly is only needed if you want a finer azimuth thread. If you decide to go this route you can get the azimuth thrust bar and pin machined at many local machine shops. Alternately, you may wish to try EZ Telescope or Bonney Lake Astro Works, maker of the Milburn Wedge. Both places perform custom machine work. I went through Bonney Lake Astro Works.

 These are the parts I used:
  1. 9 T-handle bolts: 3/8"-16, 1½" long (3 for each side of the wedge and 3 to attach the scope to the tilt plate)
  2. 6 nylon washers: for 3/8" bolt size, 1" O.D., 1/16" thickness (to be used with the T-handle bolts on the sides of the wedge)
  3. 6 stainless steel washers: for 3/8" bolt size, 1" O.D., 1/16" thickness (also to be used with the T-handle bolts on the sides of the wedge)
  4. 3 T-handle bolts (or wing bolts/thumbscrews): 5/16"-18, 1½" long (to attach the wedge to the head of the tripod)
  5. 3 nylon washers: for 5/16" bolt size, 3/4" O.D., 1/16" thickness (to be used with the T-handle bolts that attach the wedge to the tripod head)
  6. 3 stainless steel washers: for 5/16" bolt size, 3/4" O.D., 1/16" thickness (also to be used with the T-handle bolts that attach the wedge to the tripod head)
  7. 4 ball thrust bearings: for 1/2" bolt size, 1" O.D., 1/4" thickness (two for the azimuth adjuster and two for the latitude adjuster)
  8. 1 Teflon sheet: 12" by 12" and 1/16" thick (this is cut to the size and shape of the tripod head and goes between it and the wedge)
  9. 2' threaded rod, ½"-20 (this replaces the stock ½"-13 threaded rod providing finer control over the azimuth adjustments and is long enough to make 2 new rods [in case you mess up])
  10. 4 jam nuts: ½"-20 thread (these are narrower than regular nuts and help keep the azimuth threaded rod in place)
  11. Replacement T-shaped azimuth thrust bar (this replaces the cylindrical azimuth thrust bar)
Tools
To perform all of the modifications I used the following assortment of tools.
  • Wrenches: needed at various points to remove nuts
  • Heat gun: the azimuth adjustment knobs and the nuts that keep them in place are held in position with "permanent" Locktite. A heat gun is needed to soften the material and release the nuts and knobs.
  • Vice: needed to hold the threaded rod when cutting it
  • Tap: used to re-thread the azimuth adjustment knobs (more on this below)
  • Hack saw (electric preferred): to cut the threaded azimuth rod to the necessary length
  • Grinder: needed to flatten and bevel the new threaded rod.
Performing the Modifications
Clear a work space on which to set the Superwedge and the various parts and tools.
  1. Remove the hex bolts that are attached to the tilt plate from each side of the Superwedge. There should be 4 all together.
  2. Remove the latitude adjuster bolt assembly. Do this by adjusting the tilt plate so that it is close to horizontal. Remove all of the hardware from the bolt.
  3. Replace the hardware from the latitude adjustment bolt with the following in this order: thrust bearing, original spring washer, (now place the bolt through the first stationary bar), second original spring washer, second thrust bearing, both ½"-13 nuts. The end of the bolt now threads into the horizontal bar that is attached to the tilt plate. See photo. Make sure all of the hardware on the latitude adjustment threaded bolt is snug but not overly tight against each other and against the stationary horizontal bar. Tighten the first nut so that the knob turns firmly but not with any difficulty. Tighten the second nut to keep everything in place. You will need pliers and a wrench or two wrenches to keep the first nut in place while you tighten the second.
  4. Replace the hex bolts (that you removed from the sides earlier) with the 3/8"-16 1½" long T-handle bolts. On each bolt place a stainless steel washer and a nylon washer of the same size (the nylon washer should touch the wedge). Place an additional T-handle bolt and washer assembly in the extra hole on the bottom portion of the tilt plate on each side. You should now have 6 bolts connected to the latitude adjuster plate; 3 on each side. If you are located at a high or low latitude you may not be able to use the additional holes. In this case you will still have just the 2 bolts on each side of the wedge.
That's it for the basic modifications. Now to replace the azimuth thrust assembly.
  1. Using a heat gun, apply heat to one of the acorn nuts on the azimuth adjustment knobs. Apply the heat for about 45-60 seconds (about 1" away) and have two ¾" wrenches ready to go. Using gloves, unscrew the heated acorn nut while holding the opposite one in place with another ¾" wrench.
  2. Repeat this procedure to remove the knob and the jam nut from the same side (You may be able to get the acorn nut and the knob off with one application of heat. You will probably need to apply more heat to get the jam nut off.) Of course, use your hands (with gloves) and not the wrenches to remove the knobs. Leaving the set of hardware in place on the other side will make it easier to unscrew everything but you will need to remove those items so they can be placed on the new threaded rod.
  3. Once all of the hardware is removed from the threaded rod begin unscrewing it from the azimuth thrust bar.
  4. Cut the replacement threaded rod (½"-20) so that it is about 14" in length. Do this by threading 2 nuts on the rod. Place them at about 10" from one end and tighten them against each other. Place the assembly in a vice, holding it at the 2 nuts (this will prevent the vice from ruining the threads of the rod). You can then use a hack saw to cut off the unneeded length (about 4" from the nuts for a total length of about 14").
  5. Flatten the cut if it's not flat and bevel the edges with a grinder.
  6. Clean the threads of the rod by running a nut over the entire length of the rod. You may also want to wipe it down with gasoline or WD-40.
  7. Hold the new azimuth thrust bar in place and thread the new rod through it.
  8. Tap the black azimuth adjustment knobs with a ½"-20 tap. This won't be terribly precise since these knobs are already tapped at ½"-13. The thread will be a bit off but it will be good enough to allow you to get the knobs back on the rod. They can then be locked in place with the nuts on each side of them (and/or with LocTite).
  9. Put the new hardware into place. On each side you will need (from closest to the wedge to farthest): thrust bearing, ½"-20 jam nut, black adjustment knob, ½"-20 jam nut (or ½"-20 acorn nut).
  10. You're done!
See the new threaded rod, azimuth adjuster, and thumbscrews.
See the latitude adjuster with thrust bearings.


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