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 1/8" long-arm hex key, loosen the 3 buttonhead screws on the worm mounting plate.

Step 3

Using a 5/32" long-arm hex key, loosen ONLY the one socket head cap screw shown. Once loosened, re-tighten with a moderate amount of torque.

Step 4

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 thousands 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 5

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

Step 6

After you have exposed the 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 7. If the worm shaft extension is tight, please proceed to step 8.

Step 7

If the backlash is gone and the worm turns freely, re-tighten the 3 buttonhead screws and you are done.

Step 8

To release excess pressure on the worm, re-loosen the one socket head cap screw with the 5/32" long-arm hex key and tap the worm housing on the worm shaft extension cap as shown.

Return to step 3.

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 it's pier.

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

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

Step 2

Using a 1/8" long-arm hex key loosen the 3 buttonhead screws on the worm mounting plate.

Step 3

Using a 5/32" long-arm hex key loosen ONLY the one socket head cap screw shown. Once loosened, re-tighten with a moderate amount of torque.

Step 4

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 thousands 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 5

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

Step 6

After you have exposed the 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 7. If the worm shaft extension is tight, please proceed to step 8.

Step 7

If the backlash is gone and the worm turns freely, re-tighten the 3 buttonhead screws and you are done.

Step 8

To release excess pressure on the worm, re-loosen the one socket head cap screw with the 5/32" long-arm hex key and tap the worm housing as shown.

Return to step 3.