EQ6 high power vibration

[mike bacanin]

I posted this subject on CN, but no real feedback so i thought i'd try here.

I noticed a very subtle vibration on my EQ6 std, when observing jupiter last week. the moons at over x200 looked very slightly elongated. with the drive off they became perfectly round.

this also very slightly compromised fine detail on the disk.

a search on the net reveals this is a well known issue, and some mounts suffer and some don't. It also seems no amount of playing with gear mesh solves it.

it appears to be a stepper motor issue,the steps being pretty coarse.

quite frankly,even though the prices of these mounts are keen, i think i would have rather paid more for something of a higher quality. I hope to eventually get a G11.

Personally i've had enough of this chinese junk!

Mike

[Ben Ritchie]

Speaking as an ex-G11 owner, I spent a lot of time (and I mean a *lot*) tuning the mount to get it working properly. Eventually it was excellent, but IMHO you don't get guaranteed out-of-the-box performance until you hit the Takahashi/Astro-Physics level and the price that goes with it - I also have first-hand experience of a dead-on-arrival CGE that had clearly never been even been powered up by QC as it was missing wiring internally.

That's not to say they're not good mounts, they are, but - just like the EQ6 - you may need to work to get there.

[Marmite]

Mike, from now on you should only ever buy the most expensive stuff you can find. If it isn't the most expensive item, it won't be any good.

For instance, a friend of mine recently purchased a Paramount ME. It cost him a lot of money, but apparently he didn't pay enough, because he has spent a great deal of time tinkering with it and trawling online user groups, just to shake the bugs out.

Another person I know imported an AP 1200 a few years ago, at enormous expense. It was DOA, and had to be shipped back for repair or replacement. It was months before he had a working mount. Again, the purchaser was silly for being tightfisted, and not paying enough for quality.

Then there's Takahashi. A woman friend and her husband bought an EM-500. So far it's working beautifully. However I'm expecting it to burst into flames at any moment and start killing people left right and centre, because there are far more expensive mounts out there, and also because it was made by Asians.

On the other hand, a school near me bought several EQ6 Pro mounts. I thought they were blumming mugs, and it must be so, because all of their EQ6 Pros combined cost less than one decent mount. The fact that they were all working fine out of the box and are helping the students take some simply breathtaking astro images is all part of the cunning and Evil Chinese plan for world domination.

Here's a simple formula for instant success: "If you can afford something, don't buy it, because it must be junk. It's better to never have any equipment than it is to have anything less than the most expensive stuff".

[Psychobilly]

Takes me back to Harry Enfield... Loadsamoney

Which of course assumes you have the Funds to be able to adopt this approach... unfortunately the majority of people most people have to make do with what they can afford and hopefully still get enjoyment for this hobby....

Peter....

[Ben Ritchie]

Another person I know imported an AP 1200 a few years ago, at enormous expense. It was DOA, and had to be shipped back for repair or replacement. It was months before he had a working mount.

I've heard of issues with the ME blowing electronics, but never a DOA 1200 - they shake them down carefully before shipping (they're all pre-programmed with PEC, which you can't do without powering it up!) and almost everything on them can be swapped out without returning the mount to AP, so sounds odd to me.

If it was DOA, was it handling en-route? Although I also know of one that survived a fall out of the back of an aeroplane at Dublin airport without issues, so they're tough. Otherwise I can't think of an obvious reason for having to return it, so i'm curious - ex-AP1200 owner too

[DaveS]

Takes me back to Harry Enfield... Loadsamoney

Peter....

Don't you mean Losmandy

Dave

[mike bacanin]

Actually guys,in particular Marmite. i don't have loads of money, and i certainly can't just run out and buy something better.Neither is it anything to do with being tight fisted. I purchased what i could afford at the time, I just happen to have one of those mounts that has this issue,and i think ultimately i would rather put my hard earned money into something with a more consistent QC. The initial appeal of the EQ6 for me was the high load capacity and naturally the keen price, but this issue robs my scope of its real potential.

I take on board the comments of other higher end mounts having issues, but for me i think Synta is not the way to go in the future.

I believe that if i bought another brand new EQ6,it could still have this problem.

I appreciate many EQ6 owners are fortunate to not have this issue and are happy with their mount and that's fine,but that's not the case for myself.

Mike

[dweller25]

Mike,

Don't know which EQ6 you have but I believe the std version has a known issue with high mag vibration due to the stepper motors. The Pro version does not have this issue as the motors are different - may be worth looking into.

[DaveGibbons]

Mike, the dreaded eq6 vibration is something I sympathise with. Both my non goto eq6 mounts had it as well as 3 out of 4 heq5's I've owned.

despite strip downs and careful rebuilds and scope balancing I pretty much gave up. A couple of mates had eq6's "mine doesn't have it they said" . I just put a very tight double in the eyepiece told them to look with and without the motors on -yup they both had it.

It's your own fault for buying such a top notch refractor that takes high magnification , sell it to me cheap!

Dave

[adamsp123]

One possiblity is that you have inadvertantly got a loading situation where you are at the resonant frequecy of the motors steps on the mount, normally the number of steps per second is very high and if you look at a stepper motor running they are very smooth and accurate.

Try adding a weight to one end of the ota and re-balance the whole thing and see if that fixes the problem.

Pete

[mike bacanin]

Hi David,

Thanks for that comment.

My initial post reflects my frustration with this issue, and i accept my viewpoint is prejudiced by it.

I am happy to change that viewpoint if i'm looking at things the wrong way.

With regard to the EQ6 Pro not suffering this, can i ask if this is the case with all owners?

When i purchased the std version, it was because of the fact i do not need a go-to mount, and i was not aware of such reported issues with the drive.Probably i would have made the decision to spend the extra £300 or so if it meant not having the problem.

Pete, Dave, thanks for your comments.

Pete, can you clarify about the re-balance? are you referring to balancing on the Dec axis?

could it be related to the balance about the RA axis? I have tried loading slightly either way on RA, but it did not seem to make a difference.

Mike

[David Galvin]

I seem to recall from the EQ6 group that it was a resonant frequency problem which showed up at high magnification when the mount was used on a tripod at full height. If this is your set up, mine is permanently mounted on a pier, I am curios to know if it improves if you drop down the tripod legs and therefore reduce the height.

[mike bacanin]

Hi David,

I'm aware that having the tripod high can be a problem, but i always use mine at just 6 inches extended for max stability.

Mike

[adamsp123]

Mike, I mean add a weight, say 1/2-1Kg physically to the end, try top and bottom of the ota and then re-balance in both DEC and RA. If you have managed a resonant system a tiny input eg steps in a stepper motor, will cause noticeable vibrations, the classic being the Tacoma Narrows Bridge, wind (generates the resonance) v huge mass ie the bridge, bridge vibrates and falls down.

I suggest fixing the weight as solidly as possible to the ota as that itself may be the object resonating by flexing.

Worth a try IMO

Pete

[mike bacanin]

Pete,

thanks for clarifying that.

Do you have any knowledge of the comment that has been made on CN saying this is not an issue with servo type go-to motors?

I'm not knowledgeable, are servo type different from steppers once they have found target and in tracking mode?

Mike

[adamsp123]

Pete,

thanks for clarifying that.

Do you have any knowledge of the comment that has been made on CN saying this is not an issue with servo type go-to motors?

I'm not knowledgeable, are servo type different from steppers once they have found target and in tracking mode?

Mike

Steppers always "step" but have many advantages, servo motors are "constant speed" but not always so under load, have a look at wikipedia that will explain far better than I can. Unless it is a top notch servo I would prefer a stepper.

[mike bacanin]

Mike,

Don't know which EQ6 you have but I believe the std version has a known issue with high mag vibration due to the stepper motors. The Pro version does not have this issue as the motors are different - may be worth looking into.

Hi David,

I'm struggling to find anything to confirm this on the internet. It does state the motors are upgraded, and it has PEC, but i can't find a thread stating the Pro/Syntrek does not have the problem.

Mike

[mike bacanin]

Ah,what the heck,forget the G11, i'm going to start saving for the EM 200! (with hardwood tripod)

[steppenwolf]

As far as I am aware, thism is NOT a problem with the 'Pro' version or older EQ6's( like mine) that have been upgraded to the SkyScan/SynScan GoTo system. Both Pro versions and upgraded to GoTo versions have very different motor systems but I guess that if you consider the upgrade you should at leat have a good look though a system to satisfy yourself that the problem doesn't exist.

[mike bacanin]

Hi Steve,

Thanks, i appreciate your comments.

Mike

[FLO]

... the std version has a known issue with high mag vibration due to the stepper motors. The Pro version does not have this issue as the motors are different

Yes, the standard EQ6 has different motors to the more expensive Syntrek and PRO versions and can sometimes produce a high frequency vibration that is visible at high magnifications. The Syntrek and PRO versions do not .... at least not that we have seen or heard.

To be fair, the standard HEQ5 and EQ6 are benchmarks with no serious competition - at their price.

Uber-expensive mounts are not problem-free. Earlier this year FLO was asked to be a UK dealer of a very expensive and prestigious brand but after some research we discovered that it was prone to blown circuits that are both expensive and awkward to replace. So we declined.

HTH

[astromerlin]

Hi, The steppers on a non-goto EQ6 are 48 steps/rev and the ones's on the goto Eq6 are 200 steps/rev, It's a totally different drive.

John

[Astro_Baby]

I think (on the topic of those crazee asians) the fact is that almost every bit of high tech comes from Asia.

Its also true that without those Chinese bashing out Synta EQ6s I doubt many of us could afford a GoTo super-duper mount. Lets face it few of us could afford a Losmandy with GoTo.

Not so long ago GoTo, SCTs, Parabolic Mirrors, super wide EPs etc were the preserve of those with a university research budget. Yes a few bits break down now and then or have some design faults (I know - ask anyone - this time last year I was cursing Synta myself after a diabolical experience with a Sky-Watcher 200/HEQ5) but it all got sorted out for me and now its a great scope and mount.

In my time on this board and also kowing a couple of other astro-fans who dont post here I have seen;

An OO SPX 200 arrive from the factory looking like it got run over by a tank,

A Celestron 9.25 arrive from the factory hopelesly badly configured requiring a virtual rebuild,

a Vixen Sphinx blow itself up on first power up,

an eyepiece where the glass fell out on the floor straight from the box,

a Meade LX90 come out the box withe the corrector plate so loose it almost fell out and hit the deck,

an OO Maksutov with fluff and drek in its tube,

a Meade refractor with a novel endcap - it wouldnt come off the scope at all - at least the lens was well protected,

A quick look at other forums shows a succession of problems with everything astro ever made and the big expensive stuff isn't exempt from aggro either......

We just see more Celestron and Synta stuff break cos theres more of it out there.

On the whole though we should all be pretty happy because back a way the biggest scope you could have owned without living on dried bread and water would have been a 6" long tube newt on a manual EQ.

All in all we have better equipment available now to us amatuers than I would have ever believed possible 20 years ago. Its a small hobby relatively and the cost of R&D must be scary ofr this stuff.

Anyway chin up - a rebuild might fix the problem, or a GoTo upgrade and if not - well you can always try your luck with a Losmandy

[FLO]

Something I have noticed is that when expensive/prestigious kit goes wrong the owner has a quiet chat with the supplier, the kit is fixed, and life goes on as though it never happened.

Take that super-posh mount (please don't ask) we researched a while back. It is common knowledge in the trade that its power-boards blow yet we don't see any mention of it on forums or user-groups. Whereas those of us using regular kit will think nothing of discussing a problem openly here on SGL in the hope of finding a solution. I am not sure what the psychology is behind this but it is interesting (at least to me) nonetheless.

[mike bacanin]

It would be good to hear from EQ6 Pro/Syntrek owners if they actually see this problem or not in actual observing at fairly high powers. And the only way to be sure is to compare the image with the drive running and then turned off for a few seconds.

as i said earlier, i'll gladly change my perception if the high spec versions are up to the task.

Mike