front view
The "deluxe" azimuth adjuster for the LX 8" wedge
After using my wedge a couple times and attempting a drift alignment, I noticed that the stock Meade azimuth adjuster on the wedge was rough and hard to adjust. Since attempting some long exposure film photography was in my future plans, I started looking for ways to improve the stock adjuster.
front view
top view
A few visits to MAPUG site helped. Kevin Dougherty's web pages had an excellent fix. I changed the design slightly, but the credit goes to Kevin. Basically, what this modification does is to allow for a longer, finer and easier adjustment while doing a drift alignment. This can be done while viewing through the reticle EP, since you don't need to look at what you're doing with your hands.
The mod consists of the following parts, all were available at my local hardware store:
(1) 1/4-20 threaded rod,
10 1/2" in length
(2) 1/2" nylon washers
(2) Hand knobs with 1/4-20 threads
(2) nylon standoffs
(2) 1/4-20 nuts
(1) 3" section of 1/2" steel square tubing
(1) 3/8" x 1/2" cross dowel with 1/4-20 threads
This mod requires that two 1/4" holes be drilled in the wedge sides 3 1/2" forward from the center line of the 1/2-13 bolt hole for the threaded rod to be passed through. I located these two holes just above the base plate at that location.
The tripod will also need to be drilled if you want the legs to remain in the same position as with the standard adjuster. On the opposite side of the tripod from the original holes, I drilled two 1/4" holes with matching holes in the 1/2" square tubing. Once assembled, the cross dowel rides in the square tubing and provides a "fixed" point on the tripod about which the wedge is rotated during adjustment. The square tubing was attached to the tripod head using 1/4-20 bolts and nuts rather than the original screws.
| Updated 7/13/01 The square tubing was remounted using larger bolts. I redrilled the tubing and tapped the tripod head for 5/16-18 threads, then used Allen head cap bolts to mount the square tubing to the tripod. This removed the 1/4-20 nut from behind the tripod head and facilitates easier removal if the scope is to be used in Alt/Az mode. The square tubing is also more secure with the larger bolts, and less likely to shift when adjusting the controls. I'm still considering having an aluminum dog manufactured to replace the cross dowel. This should remove some backlash (longer threaded area) and some of the wobble associated with the round cross dowel in the square tubing. |
The two nylon washers and standoffs, as well as the nuts are located on the outside of the wedge, and provide a smooth mechanism for adjustment. The nuts lock the handles and nylon standoffs in place so that the rod doesn't unscrew itself.
The whole assembly makes azimuth adjustment a pleasure during drift alignments, as the knobs can be turned with either hand and with smooth, exact motion. I also placed a scratched CD between the wedge and tripod to provide a smoother surface for rotating the wedge. Usually after a good compass tripod setup, the knobs need only a turn or so to get a good alignment.
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