Astro-Physics 900DU 900 Declination Axis Upgrade

Astro-Physics 900DU 900 Declination Axis Upgrade

For all previous model 900 mounts, we can upgrade the bearing system in the Dec axis to the present standard. This will allow full tracking and guiding with excellent precision in all mount orientations including upside down operation well past the zenith. In addition, we will add a spring-loaded bracket, modify the worm bearing support for more precise worm reversals and check out all guiding functions with our test equipment. List of things we will install:

Add new thrust bearing to the Dec worm wheel
Add preload system to shaft bearings
Add spring-loaded motor box bracket
Modify the worm bearing support and adjust preload
Set all preloads to factory specifications
Re-grease worm wheel and motor reduction gears
Test the fully assembled Dec. axis for precise reversal motion
Should I upgrade my mount?: It is only when you are trying to control the mount to arc second position accuracies in declination that it becomes important to have this axis modified to the latest configuration. If you don't fit this profile, the upgrade is not necessary.

Mounts: All 900 mounts with serial number 900450 and earlier numbers, as well as 900501. Mount models include 900HDA, 900QMD, 900SMD and 900GTO models.

This upgrade is very time-consuming, so several mounts must be done at one time in order to be cost effective. Since we are providing this upgrade with no profit, we ask that you arrange to send your mount in according to our upgrade schedule. If you require that your mount be upgraded at a different time, there will be a surcharge.

Procedure for upgrade:

Find the serial number of your mount. It is stamped on a metal plate that may be located on the inside of the polar forks or in one of the honeycomb cutouts where the RA and Dec axes connect (you have to take the mount apart) .
Call Astro-Physics to determine the next available date and obtain a Return Authorization number. You can book ahead into a future month on the schedule, if you wish.
Send the dec axis to arrive between the dates specified below. We will begin the repair right after these dates, so it is important that all parts be here on time. If your dec axis is late, there may be a surcharge (to cover additional setup costs) or it may have to wait for another time. Be sure that you pack it well. We suggest that you wrap it in a thick layer of bubble wrap, particularly around the motor box area and put it in a box with packing material. Then, put that box in another larger box, again with packing material between the boxes. That will assure safe transport.
Assuming that the process goes smoothly, we should be able to ship it in a week to 10 days (allow additional time for shipping) . Please note that shipping and insurance charges are additional. We normally ship ground, so please let us know if you want it shipped by a faster service.
Upgrade Schedule.
The Dec axis MUST arrive between these dates so that we can update your mount during the full moon time, for your convenience.