EQ6 Pro noise when slewing at fastest rate

[SteveA]

I’ve got a problem with excessive noise from my Eq6 Pro mount when slewing at the fastest rate. I’ve been using the mount without problems for about 18 months and it was just the other night during a session that I started to get the most awful noise from the mount. I had set the mount up in the normal way and had been taking some pictures over a period of about an hour and everything had seemed perfectly normal, and it was only when I tried to slew to a new target that I got the problem. I immediately shut the mount down and then powered up again, but the problem still persisted. Not wanting to wake the neighbours up with the noise and not wanting potentially damage he mount I was forced to pack up for the evening.

The following day I set the mount up on the tripod, no counter weights or scope and had a go trying to see if I could workout what the problem was….I guess I was hoping that the noise would have gone away…unfortunately it hadn’t. It’s a strange noise, more of a resonant vibration than a grinding noise, but its really loud and sounds serious ! I get broadly the same noise from both the Dec an RA axis when slewing at the fastest at rate although both of the axis seem to be moving OK. If I take the rate down from 8 to 7 on the controller, I get absolutely no noise what so ever.

Something somewhere has inevitably come adrift, I’m not really sure where to look am I going to have to strip the mount down or has anyone got any bright ideas ?

[Jeff RV]

Don't know much about that mount? but sounds like a motor Bush/bearing to me, or maybe similar on a gear.

I'm sure someone on the forum will know for sure.

Jeff.

[Kai]

I would check the motor housings against the gearwheels for play.

[SteveA]

I just checked these and they seem OK and the retaining screws are tight. I made a disturbing discovery though...If I set the rate to 9 (for some reason I always assumed 8 was the highest), the noise is even worse and on the dec axis stops moving!...I'm convinced I'm going to have to strip the mount down !!

[peonic]

Does the noise appear only at the start and end of the slewing operation, or is it constant throughout the slew?

If you're not a member already, join up to the EQ6 Users Yahoo Group - it might take a couple of days for you to get your membership approved, but it's an absolute goldmine of EQ6 information - including lots of info. on the 'stripdown' should you need to go that way.

Hope that helps,

Chris

[SteveA]

Thanks Chris...you're right there's a load of good stuff on the EQ6 group that I'm hoping will help. I'm probably going to strip the whole thing down and re-grease it as this seems to be a popular suggestion, hopefully it will work afterwards...though I have to admit that I'm slightly nervous about carrying this out....fingers crossed !!!

[SteveA]

I think I may have worked out what the problem is....low battery !!...but I'm not sure as I've never had this problem before..

I've just started stripping the mount down and removed the dec axis motor, just as a matter of interest I powered the mount up with the motor removed from the mount but connected to the control board. When I set the rate at 9 the dec axis motor actually stalls and makes a sort of buzzing noise...just like it can't cope. I've even removed the larger gear wheel from the motor, so there absolutely nothing other then the spindle that is being driven...same problem. At first I though the motor must have been faulty but I'm now seeing exactly the same issue on th RA axis motor. So my conclusion either the battery is low(just a bit embarrassing I know !!) or not outputting enough oomph.. or I guess there may be some kind of issue with the control board.

[steppenwolf]

Ironically, power supply problem was going to be my first suggestion!! Try running the unit from an external power supply like a 12v car battery ( I only suggest this as you will almost certainly have one!). This is a common problem and many users now use either a mains AC PSU or a car jump start unit. This article on my website may be of some interest:-

http://home2.btconnect.com/astro-site/ac_psu_for_skywatcher_mounts.htm

[SteveA]

I've been using the 12Volt Power Tank that was supplied with the mount, getting a full charge on this always seems to take ages and I'm never sure exactly how full the thing is. I'm off out to get a PSU and see if this solves the problem..thanks for the suggestion...

[SteveA]

Back to square one I'm afraid!

I've now got an A/C PSU but I've still got the same problem!. Both motors stall at the highest slew rate IE.9. On any other rate they are fine, even 8 is OK. Is there any way I can set the maximum slew rate to 8 when doing the initial alignment as it seems to default to 9?

[peonic]

Steve,

As far as I know, allignment slew speeds can't be altered. I remember reading something that sounded VERY simillar to your symptoms on the EQ6 mailing list - and I'm pretty sure the EQ6 does something fundamentally different when slewing at speed 9 compared to all other speeds. I'd really recommend a post there, and I'd be suprised if you didn't get your problems solved within a day or two.

If you do, please come back and post the solution here, may come in handy for future reference - it's a real pain that the EQ6 group is 'closed' - especially when you're frantically searching for the answer to a problem.

Cheers,

Chris

[SteveA]

Thanks Chris, I've posted to the EQ6 group and I'll definately feed back to SGL when and if I get this sorted....

[SteveA]

It looks increasingly like the problem lies with the motor control board its self. I found a posting on the EQ6 group where some one had an identical problem, though in that case he could actually see some blown capacitors on the board, which I don't appear to have. I'm going to contact Sherwoods, where I purchased the mount from, and see if they can source me a spare control board

[SteveA]

I've just heard back from the dealer and Optical Vision want the motor control board back so they can "have a look at it"....hopefully it wont take to long for them to turn it around !

[peonic]

When my original EQ6Pro went back, they had a new one out to me within a day or two - hopefully you'll see the same kind of service.

Chris

[orion f6.3]

Take a look at this Guys BLOG http://timsastroblog.blogspot.com/2007/04/little-tune-up-for-eq6.html Give most of the common adjustments you will need. Also what power supply did you by, how many mA is is? Orion .

[Greg]

Steve,

The power tank fix is here..

http://stargazerslounge.com/index.php/topic,15281.0.html

HTH..

Greg

[SteveA]

I really wish I'd thought of recording the noise from the motors before I sent the board back ....I'm fairly sure this would have helped!

The noise I had was very different! and having had the motors out of the mount and powered up via the control board I know realise it was a metallic resonance in the mount mechanics caused by the buzzing from the motors. Both motors out of the mount and on the kitchen work top just made a buzzing..vibrating noise when set to a rate of 9, Weird I know....but as we know...it's "a strange universe!"...I'm fairly sure it was nothing to do with the power tank as I got the same results when using the Halfords PSU that Steve recommended....

[SteveA]

Hi everyone...

Just thought I’d close this thread...finally!. The reason its taken so long is that having sent the board back to OVL to get it fixed its taken them 5 whole weeks to sort it out. Matt from Sherwoods has been chasing them for the last few weeks and finally on Saturday morning a brand new EQ6 motor control board was delivered...

I nervously reassembled everything, plugged in the motors, crossed my fingers and switched the mount on......BINGO its working like a dream. No nasty noises...and for me welcome back to observing after what seems like ages, which of course is exactly what it is. Nearly 2 months since the problem first occurred and no observing in all that time....

I’ve been holding back from ordering a Skywatcher 250 PX until the mount was sorted...I just hope that doesn’t take so long (must contact Steve and get the ball rolling !)

Thanks everyone for your suggestions etc...