LX200 Leveling Procedures

       

Optimized LX200 AltAz Leveling Technique by Bill Arnett
Tripod/Mount Leveling Procedures by Rob Roy

Subject: Optimized LX200 AltAz Leveling Procedures  

From: Bill Arnett <billaznet.com>

Neither the crude leveling technique in the Meade manual nor the techniques in the LX200 FAQ seem very good to me. The bubble level is simply not accurate and the procedure in the FAQ requires an awkward step: "You will need to lengthen on leg B AND shorten leg C (or vice versa) in equal amounts to not mess up the first leveling." So I cooked up the following (it is really a lot easier than it looks). The key is to first level along a line containing two of the legs. Even though this means that the leg adjustment is not along the line being measured it still works:

Optimized LX200 AltAz Leveling Technique:

1. Very roughly level the tripod before attaching the scope.
2. Observe which corner is highest; call this corner Leg A; all adjustment will be to the other two Legs, B and C.
3. Mount the scope.
4. Free the RA lock.
5. Tighten the Dec lock.
6. Roughly level the OTA by setting the Dec to zero on the circle using the manual Dec knob.
7. Put a torpedo level on top of the OTA.
8. Rotate the OTA so that it is perpendicular to the line between the center and Leg C (i.e. parallel to the line between Legs A and B).
9. Set the hour circle to 0 (just for reference); the OTA should now point along the line 0...12 in the diagram below.
10. Center the bubble by adjusting Leg B.
11. Spin the OTA 180 degrees in azimuth (to 12 on the hour circle).
12. If the bubble is still centered go to step 16.
13. Remove HALF of the level error by adjusting the manual Dec knob.
14. Spin 180 degrees again.
15. Go to step 10.
16. Spin 90 degrees (to 6 on the hour circle).
17. Center the bubble by adjusting Leg C.
18. Verify that the bubble doesn't move when the OTA is rotated thru a full 360 degrees. If it does, go back to step 10.
19. Point south, power up, do a 1- or 2-star alignment and surf the sky!

A, B, & C are Legs; 0, 6, & 12 are arbitrary directions

Discussion:

a. Step 2 (picking the highest Leg) isn't very important; if you blow it you'll just have to adjust Leg A a bit, too during steps 10-14.

b. (Step 7) Gadget lovers may use a digital "SmartLevel" instead of a torpedo level. Instead of a boring bubble, a SmartLevel has a digital LCD readout showing the angle in tenths of a degree. It is also very easy to read; no squinting and guessing about the center of the bubble. Financially challenged astronomers will note, however, that a quick check in the hardware store showed that a $10 torpedo level is just as accurate (near the zero point, anyway) as the $100 SmartLevel.

c. Step 9 (setting the hour circle) is just for reference during this procedure; it has no external significance. The azimuth positions need not be very precise.

d. Steps 10-14 level on the line between Legs A and B NOT along the line between Leg B and the center as is usually the case; this makes leveling the last Leg (step 17) much easier.

e. Steps 10-14 also get the OTA parallel to the ground by eliminating any error around the Dec axis; the iterative nature of this procedure (step 15) is necessary since It seems to converge 3 or 4 iterations.

f. Leveling the last Leg is easy because the Dec axis error has already been eliminated.

g. After doing this once and with the OTA perfectly level adjust the Dec circle to zero; subsequent levelings will go much faster since there will be little Dec axis error.

h. This will go somewhat easier if you do it before attaching all the wires, especially the Dec motor cord.

Subject: Tripod/Mount Leveling Procedures  

From: Rob Roy <rroyexeculink.com>

For tripod/mount leveling, an ordinary cheap plastic line-level works extremely well. I'm too short to see the bubble level AND move legs at the same time. Hopping up and down and back and forth wasn't tolerated for very long when I first got my scope.

The line level was first calibrated by judicious filing of its bottom while checking on a carpenter's level. It is glued to the base near the RA lock, parallel E/W line of the housing. I can easily see it even when way down by the leg height-adjusting knobs. A flashlight can be shined on it if you're setting up in the dark. If you place one leg and the scope facing south, the west leg will adjust the E-W level. Turn the scope 90 deg. to face E and the south leg will let you level the N-S plane.

Most of the time, leveling is done in less than a minute. For the wedge (since it doesn't rotate) I have two of these line-levels placed on the N and W sides to adjust the legs the same way. Keep them out of the way of wedge-securing knobs.