Clock drive not working

Julie1 (Julie) · #1 24-07-2010, 09:49 PM

I have a clock drive for an EQ2 mount which I can't get to work. I have had it for about a year and a half. It worked for a little while then I thought the batteries had run down but this is not the problem. It seems that it is not gelling with the worm gear to drive the mount. There seems to be a lot of play in the drive even when tightened. I have tried shortening the spring to get more tension but to no avail. People who have one say they work quite well. Why doesn't mine?

Can anyone offer any ideas.

erick (Eric) · #2 24-07-2010, 11:02 PM

Sorry Julie, I cannot help, but hang in there - I'm sure someone will have experience and ideas to try.

Barrykgerdes · #3 25-07-2010, 05:25 PM

Quote:

Originally Posted by Julie1

I have a clock drive for an EQ2 mount which I can't get to work. I have had it for about a year and a half. It worked for a little while then I thought the batteries had run down but this is not the problem. It seems that it is not gelling with the worm gear to drive the mount. There seems to be a lot of play in the drive even when tightened. I have tried shortening the spring to get more tension but to no avail. People who have one say they work quite well. Why doesn't mine?

Can anyone offer any ideas.

Hi Julie

I had one but gave it to Jen
Those eq2 mounts do have a very poor worm drive
Is the shaft from the drive unit turning (you may not see it turn but you should be able to feel it at 8x with your hand on the shaft.)?

Does the mount track with the manual control with the drive disconnected?

Barry

Julie1 (Julie) · #4 26-07-2010, 09:56 AM

That's why I can't understand why it isn't tracking-everything seems to be working.

ZeroID (Brent) · #5 26-07-2010, 11:04 AM

Drive gear loose on the shaft maybe ..? Just guessing because I don't have one.

Screwdriverone (Chris) · #6 26-07-2010, 12:15 PM

Hey Julie,

I have one of these, have you engaged the cam shaft (SILVER lever) which brings the drive UP to the clock wheel? This looks like a comma shaped circle with a lever sticking out. This is able to be engaged (when driving the mount) and disengaged (when using the fine tune control wands).

I suspect that this cam is not up. Otherwise, the connector between the battery pack and the mount motor may be faulty, mine snapped at the connector when I was a bit rough with it when I packed it in the car one day and the whole silver end popped off. Check this too.

Here is a link on how to install and use the EQ2 mount motor drive. There is a mention of the clutch in there.

PS. Also there is an article here on IIS which has a GREAT picture showing the EQ2 drive and you can see the cam shaft I am talking about. The thread is here and the pic is here

Good luck.

Chris

Julie1 (Julie) · #7 26-07-2010, 08:08 PM

Hi Chris,
Thanks for that. The clutch is not the problem. I can engage and disengage that OK. I will check the connection, but the worm gear still seems to turn but doesn't seem to engage properly like there is not enough tension holding it in place. I have even tried putting a rubber band on it. It is annoying because I wanted a tracking mount for use at schools.

Julie

Screwdriverone (Chris) · #8 26-07-2010, 08:19 PM

Hi Julie,

Hmmm, the way it works is that the tension spring keeps the motor pressed against the clock wheel and the cam simply "pushes" the motor away from the wheel when you want to disengage it. The spring should be secured on the mount end with a knurled silver screw which you can tighten with your fingers. This should be keeping the drive wheel onto the clock wheel at all times UNTIL you push it apart with the cam lever.

Check the long silver T bar type screw on that secures the motor on the mount shaft to make sure it is not too tight as if it is, then the motor will not be free to spring closed so the gears can drive each other.

Give that a go and see how you go, if the motor turns, and the gears touch, everything should spin fine. Otherwise take the motor off the shaft and try turning the big silver clock wheel by hand and see if it moves. If it doesnt, then maybe something is sticking?

Cheers

Chris

Julie1 (Julie) · #9 26-07-2010, 10:34 PM

I used that link to change the tension of the spring. That's now fine. I think the main problem is in the motor of the drive itself. The small gear is very loose and sometimes doesn't turn at all, therefore it can't drive the worm gear. Looks like I have another dud piece of machinery. I have a faulty Ioptron mount as well. I think I'll just stay with my trusty Celestron dob!

I.C.D (Ian) · #10 28-07-2010, 07:01 AM

Juile,
Why not buy a new or second hand goto mount and mount (EQ5,6 )the dob onto it .I have see a few of them around and they work well ,over at Ilford this year I saw a 12" dob on a EQ6 mount .You can get a new EQ6 from the Astro Guy for $1650.00 and they are shipped out of Sydney to you delivery free.any where in Australia

Ian C

ZeroID (Brent) · #11 28-07-2010, 08:55 AM

Quote:

Originally Posted by Julie1

... I think the main problem is in the motor of the drive itself. The small gear is very loose and sometimes doesn't turn at all, therefore it can't drive the worm gear. ...

The drive gear is loose on the output shaft ?
Can you not use epoxy, Locktite or even solder to lock the gear back onto the shaft ?

ColHut (Colin) · #12 29-07-2010, 01:01 AM

Hi Julie,
You can certainly see the large gear turning slowly even at x1 speed.

Does the small ratio gear turn when disengaged from the large gear when turned on?
If it does, does it mesh with the large gear when the lever is released and stay engaged? Mine did not consistentlty thus the shims. The T-bolt should not be tight - it just tightens a screw into a thinner part of the shaft to stop the motor falling off really.
IS the RA locknut too tight, they only need a very light touch to hold a balanced scope. Is the scope well balanced?

Please attach a pic of the drive setup and maybe we can go from there.

asimov (John) · #13 29-07-2010, 01:44 AM

Surely it's just a matter of finding the little retaining hex screws that hold the gear onto the motor shaft & nipping them up..

Julie1 (Julie) · #14 29-07-2010, 04:53 PM

I think I may have fixed the problem. The little hex screw wasn't holding the gear shaft and after finding the right size Allen key and much fiddling around trying to get it to hold, it finally worked. Now it's just a matter of waiting for the weather to clear to see if it does work. Everything now seems to work. Thanks so much to everyone for all the input in trying to fix this problem.

Screwdriverone (Chris) · #15 29-07-2010, 07:56 PM

50 points to John me thinks.....well done John, you have chosen wisely.

Glad you got there in the end.

good luck with the tracking!

Cheers

Chris

adman (Adam) · #16 29-07-2010, 08:11 PM

Quote:

Originally Posted by Julie1

Now it's just a matter of waiting for the weather to clear

Good luck with that - wake me up when you see stars...

erick (Eric) · #17 29-07-2010, 11:38 PM

Good news Julie!

asimov (John) · #18 29-07-2010, 11:52 PM

Glad you got it sorted

I.C.D (Ian) · #19 30-07-2010, 06:54 AM

Juile,
It good to hear that you are back in business just one thing if it start to slip again it may worth your while to use a stainless steel grub screw ,I know that they only use mild steel screws and the little indent on the bottom of the screw wears away and will not allow it to grip the shaft

Ian C

Julie1 (Julie) · #20 30-07-2010, 10:39 AM

Thanks for the tip Ian. I'll keep that in mind although I don't intend to hang onto the mount for too much longer as I don't use it anymore.