Step 1

Place your hand near the end of the counterweight shaft and move the shaft back and forth as if to rotate the R.A. axis. This test can be done with the mount alone on its pier or with the telescope and counterweights attached.

If no play is felt or seen, then you do not have a R.A. backlash problem.

If play is felt or seen in the telescope eyepiece, proceed with the following adjustment.

Step 2

Using a 3/32" long-arm hex key, remove ONLY the socket set screw shown.

Step 3

Insert a 5/64" long-arm hex key into the hole opened by, the set screw removal. Pass it through the entire housing and out to the other side.

Step 4

Engage the 5/64" long-arm hex key with the set screw in the painted worm housing support plate. Unscrew the set screw completely and discard.

Revised May 9, 2005 - Note: This set screw's only purpose is to prevent the socket head cap screw under it from coming loose. Re-use for this purpose could increase worm gear pressure and is no longer recommended.

Step 5

Loosen ONLY the one socket head cap screw shown. Re-tighten with a moderate amount of torque. Use a 5/32" long-arm hex key to do this.

Step 6

Using a rubber mallet (or steel hammer with a block of wood or plastic), gently tap the worm housing as shown. This action moves the worm gear closer to the worm wheel, which removes the gap that you felt earlier.

Removing the space between the gears is a delicate adjustment. The distance between too much backlash and a jammed gear is only a few thousandths of an inch. The tighter the screw, the harder you have to tap with the hammer. The looser the screw, the gentler you have to tap.

Step 7

Once the backlash is gone, re-tighten the socket head cap screw and remove the black thimble like cap on the worm housing.

Step 8

After you have exposed worm shaft extension, you should be able to turn it by hand or with a pair of pliers with tape over the jaws. If you can turn it, please proceed to step 9. If the worm shaft extension is tight, please proceed to step 10.

Step 9

If the backlash is gone and the worm turns freely, re-tighten the socket head cap screw. Replace the set screw closing off the hole and you are done.

Note: Do not Re-use the lock down screw. You could tighten and jam the worm engagement.

Test for Declination (Dec.) Backlash and Correction

Step 1

Place your hand near the end of the telescope focuser or cradle plate, if the telescope is off the mount. Move the telescope or plate back and forth as if to rotate the Dec. axis. This test must be done with the assembled mount on its pier.

If play is felt or seen in the telescope eyepiece, proceed with the following adjustment.

If no play is felt or seen, then you do not have an Dec. backlash problem.

Step 2

Using a 3/32" long-arm hex key, remove ONLY the socket set screw shown.

Step 3

Insert a 5/64" long-arm hex key into the hole opened by, the set screw removal. Pass it through the entire housing and out to the other side.

Step 4

Engage the 5/64", long-arm hex key with the set screw in the painted worm housing support plate. Unscrew the set screw completely and discard.

Revised May 9, 2005-Note: This set screw's only purpose is to prevent the socket head cap screw under it from coming loose. Re-use for this purpose could increase worm gear pressure and is no longer recommended.

Step 5

Loosen ONLY the one socket head cap screw shown. Re-tighten with a moderate amount of torque. Use a 5/32" long-arm hex key to do this.

Step 6

Using a rubber mallet (or steel hammer with a block of wood or plastic), gently tap the worm housing as shown. This action moves the worm gear closer to the worm wheel, which removes the gap that you felt earlier.

Removing the space between the gears is a delicate adjustment. The distance between too much backlash and a jammed gear is only a few thousandths of an inch. The tighter the screw, the harder you have to tap with the hammer. The looser the screw, the gentler you have to tap.

Step 7

Once the backlash is gone, re-tighten the socket head cap screw and remove the black thimble like cap on the worm housing.

Step 8

After you have exposed worm shaft extension, you should be able to turn it by hand or with a pair of pliers with tape over the jaws. If you can turn it, please proceed to step 9. If the worm shaft extension is tight, please proceed to step 10.