Re: Balancing Meade LX200 Telescopes
| Subject: | Re: Balancing Meade LX200 Telescopes |
| From: | Richard G. DAVIS |
| Date: | Thu Apr 11 07:29:15 1996 |
>
> After reading many posts, with horror, about OTAs crashing into fork bases
> when releasing clamps and drive motors/circuit boards burning up(especially
> Dec axes) on LX200s, and with this latest thread on comparing 40mm Meade WAs
> vs 35mm TV Panoptics talking about balancing problems, I just had to respond!
> .
> .
> .
> I realize the Meade drive motors have fairly high torques, however, could some
> of the problems discussed on this list, i.e. drive motors failing, fuses
> and/or circuit cards burnig out, strange noises, possibly even pointing
> accuracy problems be related to OTAs being badly unbalanced??
>
> Play it safe people, and BALANCE those telescopes!!
> .
> .
The conventional wisdom from Meade to me over the years has been to "not worry
about balancing. Our LX200s have plenty of torque and power."
Nonetheless, I have had better experience with keeping things close to balanced.
Not necessarily precisely so, but balanced enough that the loads are negligible.
One MAJOR source of imbalance on the LX200 is the declination motor. While you
are in the alt/az mode, this weight isnt a factor! But, when you go into the
polar mode on a wedge, then this imbalance is a BIG factor. I work only on a
wedge, so the fork arm opposite the dec motor on my LX200 is permanently equipped
with about 2 pounds of lead to compensate for the declination drive assembly
weight.
There is a periodic, large error in RA periodic error correction on the LX200s
Ive seen reported. I suspect this is due to the scope being on a wedge, and the
RA drive loads up and then un-loads as the fork passes thru the +90 and -90
degree positions from the local meridian. Balancing the fork should remove this
effect on RA tracking accuracy.
=================================================================
Richard G. DAVIS, Ph.D. 209 Edgebrook Drive
Senior Consultant Boylston, MA 01505
Mformation SYStems Co. tel: 508-869-6976 fax: -6008
Internet: richdave@ultranet.com
