2/13/09:
I've read a lot about replacing the gear train that connects the the
motor to the worm gear with a belt drive from Warp Corps and how most
people are very pleased with the mod but been putting off buying a kit for some
time.
I finally broke down and ordered one.
This kit replaces the drive gears between the motor and the worm gear
with two pulleys and a Kevlar toothed belt for both the RA and DEC
motors. The idea is to provide a smooth drive system without the
normal backlash that you get with gear to gear
contact. These conversion kits will work on the Meade LXD75/55
equatorial mounts and many
other Vixen knockoffs. If your interested and have questions you
can join the
WARP Yahoo group or E-Mail
directly.
The kit comes with all the required hardware including some
replacement stainless-steel screws and Allen wrenches needed to
mount the pulleys and replacement screws. Warp has also developed
excellent instruction on how to do the mod as well as re-lube the
motor gear box if you so choose. A copy of the installation PDF file can
be viewed here.
My experience with the kit was basically uneventful only a few
minor obstacles. When I opened the motor housing couple dead bodies fell
out. Last summer I had a small invasion of Lady bugs and a few made
their way up into the mount, since I keep it out side all the
time.
The biggest challenge was breaking loose the set screws on the gears.
The screws were mounted by Meade using Locktite. Using a .050" Allen
wrench, it is easy to strip the inside of the set screw. For a
while, I thought I would have to abort the whole process. Not sure
how to best remove the set screws, I contacted the Warps Yahoo
group where one responder said that he used heat applied to the
location with a heat gun to soften the glue. That was the technique I
tried and it worked.
While I had the motors out I opted to re-lube the gearbox with
Super Lube on
the end of the motor. Following Warp's instructions the process was
relatively painless. You just need to have patience
and take your time. When you reassemble the gear box be careful
that you put the two intermediate black gears on the
proper shaft. They look almost alike but one has a thicker small
gear. If you switch them around the case will not seat properly
and the gear train will lock up. This is due to the fact that the
output shaft will engage both gears if they are installed wrong.
As suggested by Warp, I bought a can of Super Lube which is going to
last me a lifetime since the job only required a small amount.
When reassembling the the unit and installing the belts, Warp
suggested to re-thread the large bolt that secures the motor block to
the mount in just enough to hold the motor housing from falling
off. Then leaver the belt over the worm gear pulley. This turned out to
be a difficult job. I, instead, left the bolt out all together while
attaching the belt. This allowed me to move the pulleys closer
together and easily slip the belt over the pulley. Since the belts are
long enough I had no problem with attaching the motor block to the
mount.
All in all it took me a couple of hours to do the
modification.
2/22/09:
I put the mount on the tripod and wanted to test it out
but found that the RA motor drive was acting up. I guess I should
mention that during the disassembly of the RA gear box and
subsequent re-lube I accidentally bent the encoder wheel. I thought that
I had straighten it out enough to work OK but I guess I was wrong.
At first I thought there may be something else wrong with the
drive but I was able to swap the encoder wheel with that on
the DEC motor after which the RA worked properly. Now I need to
wait till the replacements Encoders from LXD55.com show up.
To keep you from having extra expense,
unnecessary down time and frustration , let me strongly urge you
to remove the encoder wheel prior to working on the motor
gear box disassembly!!!
I neglected to do so because I didn't have a 0.9mm Allen
wrench with witch to loosen the set screw. Thinking that
I'd be extra careful. Wrong!!!
If you need Allen wrenches Warp provided a link to a
SOURCE.
Should you be unfortunate enough to require
replacement Encoder wheels you can get them from
LXD55.com
. At the time of this writing the price was $50 for a pair.
When the new encoders show up I'll install them. do a
drive training session and I'll be good to go . Then I can see
what a difference the conversion made.