How the Meade DS Powered mounts started
Modified DS114 mount / MK66 ota ( Jan.2000 )
My DS powered telescope mounts began with a Christmas present
of a Walmart DS 114 from my wife in December of 99. From the first
night out with the Autostar controller I was hooked. I was able to see
more in one night with the Autostar
controller than I had ever seen with a gem mount. It wasn't very long at all and I had the fever for a larger scope. I had
already determined that I wanted a Goto telescope and since I already had the 497 Autostar controller I narrowed my
choices down to the ETX90 or the all new (at the time) ETX125. I decided on the ETX 125 !! Called to order one and
was told there was a waiting list. During this wait I came up with the idea that I could just purchase the ETX125 spotting
scope and adapt it to my DS 114 mount ?? Save some money and still have a goto scope. Well it turned out there was a
longer waiting list for the 125 spotting scopes because of the ETX orders...............
Since I have always enjoyed building things I started looking at the possibilities of replacing the existing DS114 forks with
wider forks to accommodate a non Meade scope.....Just might work.
After a little research and reading S & T's review I purchased
a Intes 6" MK66 Mak Cass from ITE.
I also had a plan that if the DS114 mount did not work I would build a new fork mount using larger 60 tooth worm
gears and adapt the DS motors to drive it. This would use the same settings in the Autostar and should work.
While waiting on the MK66 to arrive I started work on the DS 114 tripod. Using a cardboard 6" model I built
new fork & cradle assembly and beefed up the legs. Finally the MK66 arrived and it was time for a test.
Well the DS114 mount did work but not very well at all. Vibration was not the problem but more of a swaying
problem. Just too much weight for the tripod..........
For some reason during this time I was reading about the Alt and Az ratios in the Autostar Manual. I didn't know
for sure what they did but the manual stated " Do Not Change" and it had to do with the gearing. Being the type
person I am I wondered why can't you change them ?? So I wrote the ratios down just in case I messed things
up and started changing them. I noticed if I divided the ratio in half and did an alignment the mount only went
half way to the alignment stars. If I doubled the ratios the mount went past the alignment stars by double (hmmmm)
With this finding I decided to see if I could come with a way to use different gearing and make it work.
First mount 1-00
This is the very first DS powered mount I built ( not much to look at
) I used two automotive electric window motors
that had 65 tooth nylon worm gears. For the next two weeks I almost wore the keypad off the Autostar controller entering
new alt and az ratios. I eventually came up with a simple formula for calculating the ratios that worked !!
Since this I have built quite a few mounts and it's still a great feeling to hit the goto button on the Autostar and have
the object land in the center of the eyepiece!
MK 66 mount 4" Intes Rubinar mount
Comments / Questions
Copyright 2000-2003 Steve Bedair