[NOT REQUIRED] Meade LXD55 LXD75 Mount and/or Motor Drives

[Paullus (Paul)]

Hi all,

After more problems and disappointment with my LXD75 mount, I'm putting out the feelers for another mount, or the motor drives. I'd prefer to keep it the same, so that I can retain the tripod and Autostar (i.e no additional expenditure to get things going). Will consider other complete EQ5+ goto mounts also. Payload is a 6" reflector with DSLR.

I'm located in SEQ, budget of around $500.

Cheers

[alpharipper (Andrew)]

hey mate, whats happening with your mount, what issues are you experiencing
Andrew.

PS I have one and have had issues but seemed to resolve mine, maybe same type of issues.

[Paullus (Paul)]

Hi Andrew,

I haven't fired up the motors for a while, but this is what I posted on the LXD75 Yahoo group:

Standard Controller:
RA Motor
•Performs initial test when a direction button is pressed
•Slews both directions, at all four speeds
•Appears to function normally

DEC Motor
•Does not perform initial test
•Does not function at all when direction buttons pressed, at any speed.



Autostar #497 43Eg
RA Motor
•Left button does not slew, or is very slow to react.
•Right button does not initially function or functions intermittently; very
sudden stop/jerky when button is released on max slew speed
•Sometimes slews by itself after turning it on, stopping randomly or not at all until I switch the mount off.
•The RA coordinate displayed on screen does not change when slewed. Only changes by 0.1' which I assume it thinks it's turning at the sidereal rate.

DEC Motor
•Does not function at all, at any slew speed or direction


Other notes:
•Calibrate Motor option activates the RA motor, but not the DEC motor. No motor fault given.
•Neither motor starts when attempting to slew to an object selected in the menu.
•Occassionally the DEC motor springs to life and functions almost normally.
•All cable contacts cleaned (DEC to RA, HBX (both ends)).
•Swapping the Autostar cable end for end does not make any difference.
•Autostar has been reset and firmware reloaded.
•240v to 12v 2.5A power supply used.


I've tried two controllers, the standard D-pad style that came with it and a Autostar 497. Plus I've done the usual things like cleaned all cable contacts and tested each wire with a multimeter from board to board (ie contacts on the boards where the female connectors are attached), and different batteries/power supplies. Fairly sure the DEC motor itself works if I unplug it and plug it into the RA board, so the motor itself is ok.

Any help would be greatly appreciated.

[alpharipper (Andrew)]

You have covered most of the stuff that I covered in mine, I swaped out motors and had issues with 497 controllers x 2 that came with the scope..

I cleaned pins etc the same, cleaned boards and tested setting circles and affiliated parts.

My motors would eventually work and when aligning come up with motor faults, with or with scope and counter weights.

What I found is I borrowed another 497 controller of known working unit, and also gave mine to someone to test. They had issues but slightly different issues to me, I will put that down to different people testing different ways. I used their unit and setup to match my scope as there controller was from an etx, and mine lxd55.

The control performed and motors performed all ok. I used the controller for a few nights and only found a couple of time that the DEC motor failed. At this point I found the setting circle on the Dec was bent so corrected and all work fine after that.

This is back in 2005 and in 2007 I purchased the hypertune kit and did a full rebuild, cleaned everything, even pulled the motors apart and cleaned. Found some dust and that in them. Anyway all back to together and never missed a beat.

I am no electronics expert, but dabble, I have a mate who is electronics engineer, who I gave the controllers to.

The controllers both had moisture in them from being in cold and hot environments and the parts under the keypads had broken down.

This may not be your case nor may it be the issue, but I would see if I could get another controller and test or at least give yours to someone else. Etx scope will take them and so will some of the other scopes, not autostar II scopes as far as I know. At least you can rule the controller completely out, it had me stumped for a long time and I tell you it really gave me the you know what. I purchased a new one, my mate fix the others, which I gave to another astronomer years ago.

just to confirm when you tested with the 497 did you change all the ratios for RA and DEC etc. Did you try train drive, as well.

If I was up that way I would give you a hand.

Andrew