Knocking & jerking used EQ6, not pleased, need to rant!

[Chris]

Where do I start

I put up a wanted ad for a mount for my obsy, a very friendly chap replied saying he had a 3 year old NEQ6 minus the tripod but with pier adaptor, he described the mount as "working as expected". It seemed to fit the bill for my obsy and pier so I paid the man. My first alarm bells rang before I received the mount. as soon as he had my dosh I didn't hear anything for about a week and when I emailed him his just to ask if he had found time to send the mount his manner changed. I did however received the mount about 4 days after that, phew I thought.

Everything was there although straight the way I spotted a few things that gave me cause for concern:

1) There was a gap between the declination worm gear carrier casing and the body of the mount of 3mm at one end and 1mm at the other, this should have been sitting flush.

2) The RA clutch was held on with blue tack

3) One of the screws for tightening the saddle was very bent and difficult to adjust.

4) There was a noticable amount of play in both RA and Dec with the clutches done up (about 0.5 degrees), which is more than I'm used to seeing.

Anyway I thought all these things can be sorted so I set about adapting the pier plate for my pier so I could get the EQ6 mounted.

I couple of nights ago I mounted my new to me C8 edge on my new to me EQ6 and was excited to be back on the horse with my obsy

The goto worked flawlessly and I didn't even hear the usual coffee grinder noise like my old eq6 so I was initially well chuffed until it settled on a target and started to make a knocking noise about once a second. After looking mesmerised at about half a dozen objects around the sky (The C8 Edge is stunning by the way!), the knocking noise got worse and worse. The last object I looked at was Uranus and whilst the sight of the well defined pale green disc was the best Ive seen of this planet, the planet was intermittently jumping around in the field of view in time with the knocking sound !!

At this point I decided to call it quits for the night. I thought about emailing the guy but I know from my 38 years on this planet that it will end in an email argument and my nerves are already pretty frayed.

I decided to use Astobabys guide to strip, clean and regrease the mount and tune it up. The strip down was going well until I came to removing the dec worm gear carrier it just wouldn't come off despite being loose after removing all the screws!

Both Astrobabys guide and variuos Youtube videos showed this sliding right off so I was at a loss as to way mine wouldn't? ? ?

I decided at this point to attack the problem from another angle so I removed the mother board and Dec motor to get at it from the other side.

MY JAW NEARLY HIT THE GROUND WHEN I REALISED THE THE MOUNT HAD BEEN BELT DRIVE MODDED! This is why the worm carrier didn't come away, it was been held by the belt! I looked it up it was the kit from Rowan Astro.

In a way I was very happy to see it was belt modded knowing this is a bit of a bonus, but after a day of stripping the mount, cleaning regreasing and tuning, the knocking still persists altough I dont think its as loud so it may not effect thinks for visual work if it doesn't get any worse. I noticed that if I re introduce some back lash and have the mount off balanced with more weight towards the counterweights then the knocking is better but still there when pointing at some parts of the sky. 

I've got both axis set with about 1/4 to 1/3 degree of backlash so if its clear later once the kids are asleep I'll have another go.

I'm determined to get this mount sorted out, all the insides look good to the eye, very clean and regreased, I'm even going to sort out the blue tak clutch

Anyway rant over and if anyone has had a similar experience either with a knocking mount or a dodgy buy then please feel free to rant along with me

[Singlin]

I would download the belt drive mod instructions and disassemble the motors and belt and re-install everything.

I have a 3rd hand EQ6 that fell apart on me. After installing the belt drive mod and EQ Wedge it is joy to use.

I had over 20 people last weekend come over and see it in action (they couldn't hear it)at my local star party.

[thanders]

Don't worry!

I have also modified my EQ6 with the Rowan kit. I recall hearing that knocking sound. I think it's caused by the belt rapping over the cogs. I adjusted the tension of the belts and loosened the fastening nuts to the worm ball bearings ( I hope you understand). That's it. I now have wonderful guiding. I really think the Rowan belt kit is worth it!

/T

[spaceboy]

Interesting that you are getting knocking with the belt mod ??? From experience I would say your scope isn't balanced correctly, but not sure why you would still get knocking when it's belt driven unless it's the motor itself?? Eyepiece changes often throw balancing out especially going from big 2" wide field ep's to small 1.25" orthos / plossl.

[Chris]

Thanks guys, I did 're install the Dec side of things using the Rowan destructions but maybe I didn't put enough tension on the belt? Thanks for the suggestion :-)

By fastening nut to be worm ball bearing, is that the circlip either side of the worm carrier casing? If so I tightened that as per astrobabys guide so I could try loosening them a bit :-)

It's good to have something to go on, thanks guys :-)

[Chris]

Interesting that you are getting knocking with the belt mod ??? From experience I would say your scope isn't balanced correctly, but not sure why you would still get knocking when it's belt driven unless it's the motor itself?? Eyepiece changes often throw balancing out especially going from big 2" wide field ep's to small 1.25" orthos / plossl.

Hi, yep tried everything in terms of balance, the best position seems to be bias towards the weight bar.

[alan potts]

It is a good job you can turn your hand to such things, not everyone is honest and true but I think for the most part we are. I have always bought my stuff either new because I basically have to or from site members, I have never had a problem from a site member or the 3 times I have used A B&S, with the latter I was much more careful.

Alan. 

[Gazabone]

I've had a bit of a similar experience buying a 2nd hand C8. Stars appear as lines, not points of light and collimating it didn't do the trick. I then found the correction plate was mounted 120 degrees out ie the collimation screw that should be at 12 o'clock was at 8 o'clock. Anyway, came to put that right and I've concluded that the corrector plate came from a different scope as the screw holes to attach the plate to the camera are obviously the factory made ones (the holes are recessed and are finished in exactly the same way as the rest or the metal clamp) but the screw hole in scope is not there.

Just to compound it, the scope came with moto focus (great) except that there was no controller supplied so had to fork out £70 to get one. In the end I got another used C8 but from a reputable shop and am delighted with it.

I'm therefore left with a scope that I can only use as a restoration project and possibly take off the motofocus to either sell or put on the new C8, I won't try to sell on a duff scope.

The perils of buying 2nd hand from someone other than a reputable dealer I guess.

[ollypenrice]

I speak as someone who might one day have, at least at some hypothetical time in the future, two EQ sixes to sell. Is it worth buying a second hand one? How much do you save? Is it worth the risk?  I stress tthat mine aren't for sale.  They get used from time to time and do me very good service as backup, having done very good service prior to that as mainstream mounts. But I could probably sell them at  65 percent of the new price (and, if I did, the new owners would be happy enough). But... if I didn't know me, would I buy them from me? (This is getting silly!!  ) But the answer is 'No.' I'd buy new.

I'll never make a salesman...

lly

[Chris]

Hi Alan, yes it's lucky that I'm the tinkering type, I have a bit of engineering and scientific background but I'm generally more tenacious than able :-D

I think I've been very lucky in the past but buying on ABS so this was a bit of a wake-up call, I'll be a bit more careful with wanted ads in the future :-) I've never had a problem with buying off SGLr's, always had a great service there :-)

[Chris]

I've had a bit of a similar experience buying a 2nd hand C8. Stars appear as lines, not points of light and collimating it didn't do the trick. I then found the correction plate was mounted 120 degrees out ie the collimation screw that should be at 12 o'clock was at 8 o'clock. Anyway, came to put that right and I've concluded that the corrector plate came from a different scope as the screw holes to attach the plate to the camera are obviously the factory made ones (the holes are recessed and are finished in exactly the same way as the rest or the metal clamp) but the screw hole in scope is not there.

Just to compound it, the scope came with moto focus (great) except that there was no controller supplied so had to fork out £70 to get one. In the end I got another used C8 but from a reputable shop and am delighted with it.

I'm therefore left with a scope that I can only use as a restoration project and possibly take off the motofocus to either sell or put on the new C8, I won't try to sell on a duff scope.

The perils of buying 2nd hand from someone other than a reputable dealer I guess.

The sellers initials weren't GD were they? Worth checking :-) that's terrible, I don't know how people have the concience? Maybe you could recoup a bit of dosh buy selling it with an honest appraisal from yourself?

[Chris]

I speak as someone who might one day have, at least at some hypothetical time in the future, two EQ sixes to sell. Is it worth buying a second hand one? How much do you save? Is it worth the risk?  I stress tthat mine aren't for sale.  They get used from time to time and do me very good service as backup, having done very good service prior to that as mainstream mounts. But I could probably sell them at  65 percent of the new price (and, if I did, the new owners would be happy enough). But... if I didn't know me, would I buy them from me? (This is getting silly!!  ) But the answer is 'No.' I'd buy new.

I'll never make a salesman...

lly

Well I now think your right Olly, I'll think twice before buying another second hand mount, having said this I did get it for 560 quid minus the tripod which is 400 pounds saved on a new one.

Is it worth the saving for a belt drive modded eq6 once I've spent time sorting it whilst juggling 3 kids under 3, I'll let you know :-D

[Singlin]

Olly you are basically saying don't buy second hand from anyone else except me. Sounds like a pretty good sales pitch to me.  

Olly! regards from Luciano (Avalon)

I saw him at our local star Party and he said that he would maybe pay you a visit in October.

His new mini Oobservatoryis very slick but expensive.

[spaceboy]

 

Hi, yep tried everything in terms of balance, the best position seems to be bias towards the weight bar.

For the record it was balancing it as per the instruction manual where I found I was getting the knocking. I was finding that it was fine until I was pointing south east when the scope (newt) became top heavy and this is where I was getting the knocking yet balanced at axis to the weights or objective vs mirror was as it should be. Now this shouldn't be such a problem for short tube cass but though it worth a mention just in case. For reference https://www.youtube.com/watch?v=Tbr--zxWc-0&list=UUn0b3QC9u--0ok2n-4SURow , https://www.youtube.com/watch?v=NdRLd2i4He0

[Singlin]

Chris! you will see that after following the instructions on the belt tension you will be all good to go.

I had that knocking too and the tension adjustment did the trick.

[Chris]

For the record it was balancing it as per the instruction manual where I found I was getting the knocking. I was finding that it was fine until I was pointing south east when the scope (newt) became top heavy and this is where I was getting the knocking yet balanced at axis to the weights or objective vs mirror was as it should be. Now this shouldn't be such a problem for short tube cass but though it worth a mention just in case. For reference

 ,

Actually yes fair point, I can't say I've given as much attention to the Dec balance as the RA, I think I just made sure it was balanced once at the beginning of the session but I did use the same ep for the whole session but still yeah thanks it's worth double checking :-)

I'll have a gander at the link cheers for that :-)

[Mukv]

Greetings

I have also upgraded my NEQ6 with the Rowan belt kit and for a short time heard the click type sound in my case it was an alignment issue between the drive sprocket and the idler/guide rollers that needed very accurately lining up

it's worth re checking this.

Andy

[Chris]

Chris! you will see that after following the instructions on the belt tension you will be all good to go.

I had that knocking too and the tension adjustment did the trick.

That's great to hear Singlin thank you, jeez I'm glad I decided to rant on here! :-)

[Chris]

Thanks Andy, I feel so much better now thanks to everyone's input :-) I'm sure it must be the belt upgrade that needs tweaking now plus I'll pay more attention to my Dec balance incase it's adding pressure as well.

I'm actually feeling really happy now, this could be a great mount with some more tlc :-)

[ollypenrice]

Olly you are basically saying don't buy second hand from anyone else except me. Sounds like a pretty good sales pitch to me.

Olly! regards from Luciano (Avalon)

I saw him at our local star Party and he said that he would maybe pay you a visit in October.

His new mini Oobservatoryis very slick but expensive.

Heh heh, no, I'm not sayng that. I said that even I wouldn't buy from me!  And I'm not selling anything. If you save 40% on an Astrophysics or a Paramount or whatever, you save a lot. Enough to buy a good used car. But what do you save if you buy a used NEQ6? Enough to buy a bad second hand bicycle or, perhaps, nearly enough to fix the mount...   No, I'm not being fair to the vendors of perfectly good used EQ6 mounts... but some vestige of useful commnent may remain in my remarks. If not, ignore them!

I would love to meet Luciano and we've spoken on the phone. I hope it will happen one day. There is nothing like nicely made kit and the Avalon is just that, with no hidden bodges or ghastly hidden nasties. When you open some mounts up you look inside and say, 'Oh no.' When you look inside an Avalon you say, 'Oh yes.' I don't think it's perfect but it doesn't cost 'perfect' money and I have no regrets whatever about having bought one. It was ticking away the other night as good as gold. I think it's good and likely to deliver very long service. For the record I bought mine as a perfectly normal punter from Ian King. No discounts, no favours. (Well, only the discount Ian had on his website for everyone at that time and the favours that he offers everyone.)

Olly

[Singlin]

It was just pulling leg banter Olly  

[thanders]

Thanks guys, I did 're install the Dec side of things using the Rowan destructions but maybe I didn't put enough tension on the belt? Thanks for the suggestion :-)

By fastening nut to be worm ball bearing, is that the circlip either side of the worm carrier casing? If so I tightened that as per astrobabys guide so I could try loosening them a bit :-)

I mean this "ball bearing nut". If you tighten it too much, the worm will get stuck.

The balancing is not so important. I mean you should of course balance, but the resulting force on the belt will be minor.

/T

[Chris]

Yeah that's the one I was thinking of thunders, thanks for the pic :-) I will loosen it off a bit.

[Quatermass]

For what an ordeal mate hope it all gets sorted for you allways a risk buying second hand but sometimes its the only option.

[laser_jock99]

 Is it worth buying a second hand one? How much do you save?

lly

I bought a second hand EQ6 for £250......so I saved about £700. Stripped and re-built now it's a sweet runner.