Re: lx200:dec axle binding
| Subject: | Re: lx200:dec axle binding |
| From: | Gerry Reynolds |
| Date: | Wed Apr 24 07:25:18 1996 |
>How does one make this determination? My OTA has never freely swung between
>the forks, and this year Im planning on fixing that according to your
>previously posted instructions. But, as I recall, those instructions only
>dealt with freeing the OTA by making sure the fork arms are properly aligned
>. Whats the deal with binding in the DEC drive/worm gear, and how can I
>tell if thats the problem?
>
>Dick Green
You have already made this determination if your OTA binds up with the clutch
free. The only part of the scope moving in this case is the DEC axis and its
bearings. Barring some foreign material caught up in the works, if it is
binding with the clutch free, this would indicate a misalignment or a defective
bearing. I would assume the misalignment for starters. Yes the instructions
only dealt with the axis as this was my problem. I have had the worm and drive
gears removed but not to fix a gear binding problem so I dont have complete
personal experience with this. For your case, I would deal with one problem at
a time (your DEC axis) and then see if you have gear problems.
>No binding with the clutch unscrewed. With clutch engaged, after a minute or
>two, enough friction builds up and the "tick" starts; I can stop the ticking
>reproducibly by grabbing the upper end of the fork/dec drive housing and gently
>torquing it toward my right shoulder, which produces a slight creaking sound
>(like a salvo of the little ticking noises) following which, in a minute or two,
>it will start up again.
>
>Balancing or unbalancing the scope makes no difference. The dec drive gear
>assembly and motor are silent with respect to the noise; it is audibly coming
>from above the motor/gear assembly, and seems to relate more to the fork arm
>itself, judging from the palpable vibration the tick produces there. At higher
>slew rates I dont hear anything amiss, only at the clock drive rate.
>
>-Don
Weird! Heres a thought. If you are inclinded, remove the DEC gear cover and
the worm gear assembly. With the clutch engaged try to move the OTA (instead
of by grabbing the tube) by turning the drive wheel by hand. Maybe the torque on
the drive wheel is affecting the bearings. Maybe theres some foreign material
bound up in the works. If you still get binding, you have eliminated the worm gear
assy and the teeth on the drive gear in which case you will need to remove the
drive gear and look for the source. If not, remove the big drive gear, clean it
up and regrease it. Also clean and regrease the worm gear before reassembly. If
this doesnt fix it, you may have to call Meade.
Hope this helps
Gerry Reynolds
gerry@fc.hp.com
