Primordial Light: Meade OTA Removal

Primordial Light: Technical

Removing a Meade OTA from its GPS Fork Mount

I am by no means the first to remove a Meade LX200 GPS Optical Tube Assembly (OTA) from its fork mount and install it on a another mount. I installed mine on a Losmandy G-11 German Equatorial Mount (GEM). This article provides full, illustrated instructions that will show you and your assistant how to remove a Meade LX200 GPS OTA from its fork in such a way that the fork is undamaged and reusable. Hint of what’s to come: required tools include a propane torch, a hammer, and some nerve.

Please read this page in its entirety before attempting to carry out this procedure. This procedure is not difficult for a person who has a modicum of skill and experience in the use of tools. This procedure could lead to personal injury, property damage, and/or damage to your telescope if carried out by an unskilled or careless worker. If you do not have the requisite skill and experience, do not attempt this modification yourself. To ensure safety and prevent damage, this procedure requires two persons to perform.

Conventions: For the purpose of this exposition, the left fork arm is the same as the east fork arm. This is the arm that is on your left (east) side when you are standing on the north side of the telescope and the telescope is aimed southward. The right fork arm is the same as the west fork arm. This is the arm that is on your right (west) side when you are standing on the north side of the telescope and the telescope is aimed southward.

First Things First

Look again at the photo at the top of this page. If the three hex screws that I have circled in red-- the ones that attach the tube to the one-piece bracket/shaft -- are accessible without removing a fork arm, then you and your assistant may be able to remove the OTA by merely loosening the Left (East) fork arm as described on this page (They were not accessible on my 8" LX200 GPS.)

Above: Before you remove any screws or bolts be sure to make witness marks as shown above on all three surfaces where the left fork arm connects to the base (the bottom is open, as that’s where the attaching bolts are, as we will soon see.) This will allow you to maintain orthogonality when you reassemble the fork (providing that the declination axis and the right-ascension axis were orthogonal when you began.)

Left, or East Fork Arm

Right, or West Fork Arm.

Above: Remove all of the hex head screws from the left and right fork covers. Then unscrew both knobs in the direction shown. Remove the knobs and the fork covers and set them aside.