What am I doing wrong (Nothing by the looks of things)

Glenhuon (Bill) · #1 09-01-2008, 05:22 PM

I'm having great problems with drift alignment on the EQ5. Spent a couple of 2hour sessions going through the how to from IIS and it still doesn't track properly.
Best exposures I can get are about 2 secs, which is about as much as I could get with the drive turned off. Just run a check on the drive speed, set it going and noted the start time and RA position and the first 1 hr run looks like it might be a bit slow. Just running another check over the next 2 hours to see if it still the same. Has anyone else had this problem with the EQ5 ?
I notice there is an adjustment pot inside the controller but loath to play with it untill I'm sure thats the trouble.
Any advice much appreciated.

Bill

Glenhuon (Bill) · #2 09-01-2008, 09:34 PM

Tests are finished and its definitely the drive thats slow by about 15 mins in every hour. I am assuming that the graduated scale on the far end of the polar axis thats marked 0 - 12 is 2hours per major division. Anyone had to adjust the speed on an EQ5 ? I'm game to have a go but would appreciate any input.

Cheers
Bill

Karls48 (Karl) · #3 09-01-2008, 09:41 PM

Bill, I know that I’m stating obvious but from my experience it is better to check obvious things first.. I got GS mount converted to work with Autostar. Few times tracking and Goto went crazy. After blaming everting possible and impossible I found twice that the clutch was slipping because I did not tighten clutch lever sufficiently. One time the power cable got tangled on the tripod leg and once my battery was just about to die and voltage to the mount was only 9,5V

Glenhuon (Bill) · #4 09-01-2008, 10:41 PM

Hi Karl
Clutch seems to be ok,. Mount is 6v powered, either with 4 D cells or 12v to 6 volt (actually 6.7v unloaded, but doesn't drop below 6.3v when working)regulator on a 12v 33 AH Gelcell. Either way it runs slow. Was wondering if anyone could give me a hint on what NOT to do when making the adjustment as this hand controller is a replacement for the original which died on me. Its only a straight drive, no goto as yet.

Cheers
Bill

Omaroo (Chris Malikoff) · #5 10-01-2008, 08:03 AM

Bill - are you absolutely positive that it is balanced in RA?

Also - I stripped mine and cleaned it right out a while back. I re-greased it with about 1/4 of the junk they'd forced in there back in China - and with decent quality while lithium grease. I had so much stiction before it wasn't funny.

Glenhuon (Bill) · #6 10-01-2008, 08:57 AM

I'm guessing its OK for balance as I can move the scope and counterweight through about 30 deg either side of horizontal/vertical with the locking lever off and it stays where I stop it. Didn't think about the grease, could be. I'm forgetting these are just little 6v steppers and it wouldn't take much drag to slow them down. I'll pick up some White Lithium Grease today and check it out. Been meaning to have a look see if its fitted with roller bearings on the RA worm shaft anyway.

Cheers
Bill

Glenhuon (Bill) · #7 10-01-2008, 12:02 PM

Mount stripped and checked. It has the bearings fitted and the grease looks like it was White Lithium and not overdone, but cleaned and replaced it anyway. Adjusted the worm to take up backlash and it has minimum now and feels very smooth and free with no tight spots. Tweaked the balance and it can now be put in any postion with the lock off and it stays there. I had the push on knob on the short end of the worm shaft and it looks like it could have been dragging against the adjusting nut, moved it to the other end. The locking screw for the RA setting circles at the back of the mount will also put a drag on the shaft if its overtightened. Test proceeding, and hopefully all should be well.
Thanks for the advice guys.

Cheers
Bill