Installation Guide of Telescope Drive Master

Encoder-adapter for Celestron AVX mounts

First of all, thank you very much for purchasing our product called “Telescope Drive Master” and congratulation for your decision. This system will improve the tracking accuracy of your Celestron AVX equatorial mount dramatically independently from its original periodic error amplitude because both periodic and aperiodic errors of your mount will completely be eliminated using our real time, ultra high precision correction system, without using conventional autoguider. We guarantee that your tracking error will remain within 2” (two arc-second) range ptv total (or ±1”) or less within 95% of your exposure time. It means your mount will have the best tracking ability among the amateur and semipro equatorial mounts all over the world (even if your dome-shutter is closed…).

To achieve this unbelievable result, before the installation of your Telescope Drive Master, you need to complete a very accurate polar alignment process of course. Please find our proposed method to do that among the uploaded documents of www.telescopedrivemaster.com website.

TDM controlling system contains two main logical units or parts: a high precision encoder unit (encoder with its torsion-free coupling and a mount-specific mechanical adapter) attached directly onto the RA shaft of the mount and an electronic device (a sort of “black-box” with connectors, power supply and cables), which receives the electrical signals arriving from the encoder unit and sends control instructions to the mount’s driver via its auto-guider input connector. So you will need to install the mechanical elements and the electronic device as well but do not worry: both of them can be done very easily.

Please find the drawing and description of electronic connections to be set in the relevant sub-menu of the TDM website because this schematic diagram is the same for every telescope mount. In this document you will find the mount specific instructions for mechanical adapter and encoder installation only.

Before starting it is highly important to emphasize that both encoder unit and its adapter elements are sensitive mechanical parts!!! Do not drop any of them; do not stress them during installation!!! Handle with care! Any damages of these parts can destroy product’s accuracy.

Just Allen-wrenches, a Torch screwdriver, and a spanner will be needed for installation.

Mechanical parts of the adapter have been assembled in one unit before delivery. The risk of any mechanical damage during transportation is much lower in this way but, it means, you need to disassemble them before installation. You just need to remove the screws.

Before assembling parts during installation, please always check and clean all of the threads and surfaces of the lower end of the RA shaft and encoder adaptor elements if necessary. Use clean clothes (not nylon!) for smooth surfaces and a dry toothbrush to clean the internal and/or external thread(s) of the RA hollow shaft if it is necessary. Only the clean and tight mechanical contact between surfaces will provide correct mechanical coupling and positions.

Step 1:

Turning it on counter-clockwise, please remove the black conical plastic cup of the RA shaft. (If you want to complete rough polar alignment using polar scope, you need to do it at the end of this and before the next step.)

Step 2:

Next step is attaching encoder shaft into the hollow shaft of RA axis. Do not touch the long cylindrical surface of the encoder shaft with any metal tool (e.g. pliers)!!! Use appropriate size of spanner only, maybe coach-wrench at the root of this part clockwise, and tighten it. This part cannot have any offset compared to the RA axis. If both threads are clean enough, the thread profile-angle will have to be able to centralize the geometrical axes of RA hollow shaft and encoder shaft without any problem.

Step 3:

Now, screw stator ring into the casting house of the RA shaft completely and fix its position using two pre-installed worm-screws. It is very important to fix this part and ensure its position against rotation using these screws because stator must not move at all.

Step 4:

Now, please release every screw (2x4pcs in the flat springs) of the coupling of the encoder a little bit but remove completely the two ones only which fix the front part. (See “Installation Guide for TDM Encoder Coupling”:

http://mda-telescoop.com/index.php?option=com_content&view=article&id=63&Itemid=98)

In this way, you can detach the front part of the coupling, and can fix it onto the stator of the adapter.

Step 5:

Now, please check the well released screws in the shaft-fixing clamps on both front and back side of the encoder and push the encoder (and the coupling parts on its front side) firmly onto the previously installed and clean steel shaft. Please do NOT apply hammer on encoder!!! You have to be able to push it gently onto the shaft by hand. Fix the coupling parts again using 4x2 pcs of screws in the flat springs and tighten them well.

Step 6:

Using Torch screwdriver, tighten two screws well in the clamping ring on both ends of the encoder. You can reach the screws on the front side of the encoder via one of the holes created especially for this purpose in the middle of the flat springs.

Congratulation, you successfully installed the encoder onto your equatorial mount and you have finished the most difficult part of the installation process!!! The gaskets of the Heidenhain encoder protect the sensitive internal encoder parts against weather so additional protective cover is not necessary.

You just need to create cable connections among telescope electric units according to the relevant part of the User’s Guide.

IMPORTANT-1 → Encoder cable must not move or swing during exposure!!! In spite of rigid and torsion-free coupling, the smallest force on the encoder can result just tiny, one-two arc-second tracking inaccuracy which destroys the accuracy of TDM.

IMPORTANT-2 → Please do not connect or disconnect encoder cable when TDM is switched on!!! It can destroy inner electronic components of the TDM box.

Additionally, please find several useful tips and tricks in the User’s Guide of TDM and other documents found visiting www.telescopedrivemaster.com website.