N4646W

I have the Mead LXD 55 mount with a 10" f4 reflector. I went through the whole system as it was a mess from being stored in a carport for several years. The party that initially owned the system had upgraded the mount motors and gears. The gentleman that we purchased it from never used it as it was more than he cared to invest the time in to learn to use it.
So, now I have it back together. When I do a polar alignment, it swings to pick up the first point, then it wants to crash the DEC housing into the control panel as it swings to the second point. It is traveling 180 from the direction it should be going. I've checked the Autostar, and it was set to the northern hemisphere, proper lat and longitude for my location, time zone, time.
I'm in hopes someone on the site is familiar with this mount that might be able to point me in the correct direction. I have the manual for the mount, and am either misreading it or I have a bad circuit board in the mount or the controller. I know it is an ancient unit, but it's all I have, and Mead is of no help as it is "obsolete". No one in the local astronomy group has a tracking mount, and they have encouraged me to get this unit up and running.

Ron

Europa Loc: West Hills, CA

Here are a couple things to check, sorry to mention some obvious:

Time is correct am/pm
You mentioned durning your polar alignment, it it sounds like you are doing an alignment. Polar alignments don’t require the scope to slew to any stars, alignment does.

When you initially setup, is the mount properly setup with respect to the Polaris? Basically, when you setup the mount, its in its native home position and the scope is pointed at Polaris. After you have the polar alignment completed, then you move onto the alignment. This is where you will begin to slew to different stars.

If this doesn’t help, try leaving the scope off the mount and “pretend” to do an alignment. Will the run away scope stop, or does it go further than the 180? I’ve had an older Meade, and run away issues can be caused by a few hardware issues. 1) power supply is not exactly what it should be, is the voltage varying slightly 2) the wire is bad from the hand controller to the scope 3) hand controller is bad. These may not solve your problem, but they did cause me to have run away affects from my old Meade.

A side note, how heavy is that 10”? You may want to make sure the LXD has a high enough payload capacity to handle it.

N4646W

Thanks for replying.

I was trying to do the 2 star alignment, with out the scope attached, just to check things out. The housing for the DEC slews to a configuration where it crashes into the panel as it searches for the 2nd star in the alignment procedure. I did try to manually move the Dec 180 from what is (supposed to be ?) the start configuration and it does the same when searching for the 2nd star in the procedure. I'm guessing it might be the hand controller, it gets kind of finicky at times which is not a good sign and will not let me do a reset. Hope to find one that I can try before I have to purchase one.

Yes, your concerns over the weight of the tube troubled most who had this unit. I believe, and from what I have read, that the modifications to the motors and gears by the initial owner, addressed this situation as I was told that he did a lot of photo tracking. I modified the counter weights (it did not come with the unit) to use less weight further out to balance the system. Seems to work well and allows more sensitivity when changes are made.

Ron

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