Vixen SP LXD55 Retrofit

After upgrading from an ETX90 to a Celestron C8 on a Vixen Super Polaris, I wanted to retrofit it to Meade Autostar GOTO.
I tried the original Meade DS motor retrofit using brackets and shaft adapters designed and made by Chris Erickson. After playing with this for a while, I came across a pair of Meade LXD55 RA motors, and decided to try retrofitting those to my new Vixen mount.

These motors bolt directly on to most CG5 and other Chinese clones of the Vixen series of equatorial mounts. These motors require some minor modifications though to bolt on to a Vixen SP mount.

Tools needed: allen wrenches (to take motor apart), wrenches, hacksaw and file.

Parts needed: 5 - 5/16th inch washers, 1- 1inch 4X20 allen bolt for DEC axis, 1- 2 1/2 or 2 3/4inch 1/4X20 bolt for RA axis, 1 penny

Declination Axis

First of all, remove the motor housing from one of the LXD55 motors, being especially careful of the fragile encoder wheel.

This is the unmodified motor base.

The slots on the motor housing fit the tabs on the DEC mount. Unfortunately the tabs are a bit thicker than the slots on the motor base.

I just took a hacksaw and cut the slots a bit wider. On this particular mount, while I was experimenting with different configurations, I removed more metal than was necessary, but it still fits fine.

A little of the plastic on the DEC motor case needs to be removed because the telescope mounting plate gets in the way.

                     

After putting the motor back together, and loosly bolting it to the mount, I inserted a penny as a shim to tip the motor up a bit, and make the gears mesh completely.

 

RA Axis

            

As you can see, I am still using the RA spacer from my DS retrofit. You will still need a spacer there, but not necessarily as thick.

The RA motor attaches by a bolt through the mount RA axis. If you just bolt it directly on though, it rubs on the mount (as you can see in the picture!).

I took the simple aproach, and used a stack of 5 washers to make a spacer.

While tightening the bolt, just slide the motor forward until the gears mesh completely.

As mentioned earlier, I used 2 RA motors in this mod. In order to make a RA motor to function as a DEC motor, all you have to do is make a patch cord as specified in this wiring diagram by Christopher Erickson.

 

 

Completed mount

 

Looking for more info on retrofitting your particular mount for autostar goto?  Join us in the Roboscopes Yahoo Group!

Anyone interested in Astronomy in Alaska?  Please join us in the Alaskan Astronomy Yahoo Group!

Everyone is Welcome!