MX Doesn't Work

[NilRecurring]

My MX has so far been a bit of a disappointment. While I am very impressed by it's pointing accuracy and tracking it unfortunately keeps throwing up the dreaded "Mount Hit Something or Is Out of Balance" error in both RA and Dec, sometimes in only RA and sometimes only in Dec.

The issue is so severe that I can't even finish a T-Point auto calibration. The mount always gives out the error (in both axes) when the OTA is west of the mount. It almost always happens during the start of a slew or occasionally when it's just to about to arrive at it's given target.

I had to reboot the mount 5 times just to get through a 49 point T-Point calibration.

The error happens only in RA when the mount is just tracking and this error can happen at pretty much any point in the sky. I am not sure what's so wrong the mount. I have adjusted the camstops of both axes. What interesting thing I found was that the camstop pin doesn't go all the way down even if I loosen the button head more or even if I loosen the setscrew (as instructed in some threads on SB forums). Here's a picture of it - this is how much I was able to get it down and it doesn't go further than this:

http://i.imgur.com/FVSz8dS.jpg

Does this seem a bit odd to anyone else here? Both motors also run a bit hot - I'm not sure if that's normal. For what it's worth, I have checked and rechecked my balance countless times. As soon as it throws up the error I check the balance and the OTA always stays put.

I've created a large post over at SB and I'm hoping I'll get a response on Monday but they can a bit slow when it comes to these things. My biggest fear is that I'll have to send the unit back and that'll cost a pretty penny. Here's a video of the error:

http://www.youtube.com/watch?v=AO2Sc35q_Tg&feature=youtu.be

[rat156]

Hi,

You are not alone with this problem, even though SB are not willing to admit there is a problem. A quick look at the posts on the SB forum will show that many MX's have a similar problem. Mine turned out to be the drive belts, they were black and frayed, make sure yours are grey.

Cheers
Stuart

[NilRecurring]

I remember your unit having problems, Stuart. My belts are gray though. I really hope SB comes through - otherwise all I have is a $9000 paperweight.

[gregbradley]

Wow, the PMX is really having some quality control issues. Its a fabulous mount when it works but it is a bit touchy.

The cam pin has 2 threaded screws on either side of them. They are supposed to be 2.25 to 2.5 turns out from fully in. They control the tension.

If you have them too tight you may get stalls. If you have them too loose the gears will slip with a horrible grinding sound.

I am not saying this is your problem but if your motors are hot it sounds like they are straining. Perhaps this is why. At least its worth a check.

Perhaps the error message is not really stating the problem and it really should say it stalled.

SB will come through but its probably going to take some patience. But once all set it is a beautifully performing mount. I wish mine did not have that 3 way switch. Its simply not worth the drop in reliability to be able to loosen the gears easily. Its not like it was hard to do on a PME. So its not really even a feature that is worth it especially when it introduces so much fussiness. Its poorly engineered and needs to be redesigned to be more bulletproof and less sensitive to accurate adjustment.

Greg.

[NilRecurring]

Thanks Greg, I'll check the threaded screws on the side. Can they just be turned by hand? Completely agree about the 3-way switch!

Also, do your motors run warm at all?

[NilRecurring]

Greg, I did as you suggested but no dice. The issue still occurs. I also hooked up a amps meter to the mount and measured the current. Whilst tracking, the mount starts from using just 200 mA and then ramps upto 550 mA where the mount gives the error in RA. This happens over the course of 5-10 minutes. I don't understand why the current increases - if I switch to balance mode, the current drops to 200 mA.

[Paul Haese]

I had a similar problem with my PME. It turned out being a dicky cable. It took me a while to find the problem but once I did it I have not seen the problem again. It was the cabling coming from motor that was the problem and it was being moved by other cables and causing a short. Perhaps take a look around the cables and see if this is a problem. Probably a long shot and not even the same mount type but it will most likely have the same motors and the same cable.

[NilRecurring]

Paul, how did you find out it was a short?

[Paul Haese]

It was a process of elimination. I stripped the mount several times (there is a thread here about the issue) and thought it was grease on the sensor at first but in the end I found I touched a cable and the alarm stopped upon reboot. It was more good luck but I found out later it has been a problem in the past. Not sure how much room there is in the MX mount but worth some investigation all the same.

[NilRecurring]

Thanks Paul. Will see tomorrow if I can find something with the wires - but the considering how the current increases on the ammeter I don't think it's a short circuit - otherwise I'd see a huge rush of current. But I'll check nonetheless.

Really hoping SB responds tonight.

[Tandum]

If it's a cable connection issue, I highly recommend DeoxIT which you can get from jaycar. It's a 2 part cleaner, the first dissolves oxides etc from the contacts and the second preserves them. Not Cheap though and the spray version goes no where, get the other.

http://www.jaycar.com.au/productView.asp?ID=NS1436

[DavidNg]

Hi, sorry for your troubled PMX. Perhaps one can try to separate TheSkyX issue and PMX hardware issue by slewing the mount by hand control unit without TheSkyX? Good luck

[CDKPhil]

I had this problem with my MX two builds ago.

I never had this issue before, as soon as I installed build 6934, I had the exact same error as you have mentioned. It was nothing to do with a hardware problem.

I posted this problem with a video of the motor running in the balance position to the SB forum. It showed that when the motor was running and then aborted it would stop, then run at full speed in the opposite direction. See this link http://www.bisque.com/sc/forums/t/18508.aspx?PageIndex=1

I also noted that when the mount was slewing to a target it would over shoot and reverse to come back to the target. This reverse was causing the stall.

Now I have the latest build for Mac and the problem has miraculously gone away.

I don't know what caused this error, I do know it was something to do with OS 10.8.2, It did not occur on an older Mac running 10.6.8.

I have been running the latest build and doing a lot of other testing, I have not had one problem. Every thing is back to normal.

I don't know what OS you are using or what build of The SkyX. Install the latest build if you have not already done so.

Cheers

Phil

[graham.hobart]

The issue I had was the DEC cable not seated properly- would not synch and then would stall. Check the plugs and tension on the cables.
Cheers
Graham.

[CDKPhil]

If the latest build does not work you could try slowing down the Slew rate to help diagnose the problem. Image below.

If the mount is over shooting the target and going into reverse at full slew speed, a slower rate may help overcome the abrupt change in momentum.

Just a suggestion,


cheers

[Joshua Bunn]

Hows the tension on the grey belts, maybe this could be making the motors work harder than they need to be?

Josh

[gregbradley]

At least that is one variable you can tick off the list. Some good posts here about possible causes. I guess you'll have to make your way through them until you arrive at the actual fix.

Greg.

[NilRecurring]

Took a good look at the cables but they all look OK to me. CDKPhil, I am using the latest TheSkyX build but I am able to reproduce the error without connecting the mount to the PC.

Here's what I just posted on SB: However, here's something else that I noticed today - when using the hand controller I'm moving the Dec. axis and I 'successfully' I end up blinking it's LED the RA axis follows 5 seconds after - without me touching the hand controller or anything else. Why is this? Aren't both motors stopped whenever the errors in either of them?

Even more curious is the following: when I move the mount in Dec. only via the HC and then stop moving in Dec the current consumption doesn't drop down to normal current consumption for tracking. Let me clarify: suppose the mount is consuming 300 mA whilst tracking ONLY (this is with perfect balance). I slew the telescope in Dec via the HC - while slewing the current consumption increases to 600 mA or so. However, once I stop slewing in Dec the current consumption does NOT drop down to 300 mA - it stays at 600 mA or so. Shouldn't it come down to 300 mA or whatever the current consumption is when the RA motor is tracking at sidereal rate?

So if the error happens in Dec., why is the mount indicating it in both axes? And yet, when the error occurs in RA whilst tracking it's the only LED that's blinking. Dec does not blink.

[Terry B]

This all seems very poor for what is a very expensive mount.

[whzzz28]

Yes this thread concerns me as the PMX was on my "next to buy" list.
That AP 1100GTO is looking even better now.

[multiweb]

Same here. Been following this for a while now and although I understand there is always 'tweaking' involved and most of the users out there seem satisfied with their mounts, the level of support provided by the supplier is very inconsiderate at best. Sheehh... we're talking about a $9k purchase here? Unreal...

[Marke]

I am with Marc and others , I dont understand what the appeal is when more
robust reliable mounts are available at similar price ?

[RickS]

But they aren't red and futuristic looking :lol:

More seriously, the PMX is a nice package with good capacity for the price and the software integration is very good (if you like The SkyX...) It's just a shame that they appear to have released the mount before it was quite ready for prime time. No doubt people will love them once the early problems are behind them.

I'm still sticking with my AP900, of course. At least, until I get to the head of the AP1100 waiting list ;)

Cheers,
Rick.

[NilRecurring]

I agree it's absolutely inexcusable for the standard SB is trying to set.

That said, I think I made some progress today by centering the worm in the Declination as Sarah at SB suggested. The Declination isn't throwing up errors today. I've done 6 or 7 50 point+ T-Point calibrations, and the Declination hasn't given me any issues - previous the Declination axis would give the error but the mount would show it present in both axis (no idea why. I know it was in Declination because if I changed Declination to Track and RA to Balance, the mount would still give errors but not vice-versa).

The current consumption also seems a bit down today (approx 300 mA while slewing. It ranged form 300 mA to 600 mA before). Thankfully no errors!

However, as I had mentioned in the OP, I have a separate issue in which the RA axis gives up whilst tracking. This is still happening (no surprise there as I did not adjust the RA at all) so I will ask SB for further advice. What I've noticed is that the current consumption while tracking (400 mA) is higher than while slewing! The mount even runs hotter while tracking than while slewing (1 degree difference as measured by the Bisque TCS)

Though I'm still cautious about this good news, I hope at least one axis is fixed.

[CDKPhil]

I am glad to hear you are making some progress.:)

Cheers

Phil

[TrevorW]

Do you get a 5yr 100000klm warranty, if not I'd be asking for one at that price.

[frolinmod]

Software Bisque support is excellent so long as you are affable, reasonable, persistent, firm and are willing/able/capable/motivated to do some work yourself. If you're an on the ball self starter type, it's quite good.

I get the impression that most of you guys down under are very capable, so this should work out well. It's just a matter of time. Keep working it.

Remember, it was y'all who solved the PEC problem.

[NilRecurring]

I've managed to solve the issue in RA, but I'm not sure if that's the 'right' way to do it. Sarah had asked me to center the worm and adjust the camstop again - I did so and it didn't help.

I then decided to turn the screws on either side of the camstop pin 1 turn loose i.e. they are now 3.5 turns loose from fully down. This has actually fixed the issue - I ran the mount (indoors) for almost 3-4 hours, and it was perfectly fine. The current consumption is down, and the mount is running a bit cooler too.

I asked SB if this was okay or would this comprise guiding or introduce the backlash, but they didn't reply to me today. I wish they had and if this adjustment was acceptable then I could have used the mount tonight. So I'm asking you guys, do you think this is OK or should I go back to 2.5 turns and try to find another solution (though I'm not sure what I can try other than this). Would appreciate a response as today's Friday and the forecast is clear so I'd to use it outside without issues (*fingers crossed*)

[frolinmod]

I don't see how anyone off the street could possibly know for certain. I don't know what Sarah's qualifications and experience are. Expecting her to solve the problem (in a timely manner) on her own may be realistically asking too much too soon. Steve Bisque should take charge of the matter and own it. Have you tried emailing Steve?

[NilRecurring]

I'm pretty sure Steve has seen it. He has been replying to MEII issues today.

[Logieberra]

P.s. Frolimond. The southern PEC on MX mounts running Windows is not fixed... so far as I can tell. There is a discrepancy between Win and OSX. Only OSX seems to correct PE. Something under the hood?

[frolinmod]

What does everyone else think, is it fixed in the latest Windows daily build or not?

[gregbradley]

If 3.5 turns of the screws on either side of the cam stop is working then it seems to be no problem.

The problem will be if its too loose that the mount will slip on its gears too easily. For example if you take the camera off your scope and forgot to lock the axis first then it will slip whilst making a horrible grinding sound. It apparently does not damage the gears but you wouldn't want it to happen all the time.

So if that is not happening then I think you are fine.

This 3 way switch thing/cam stop/tightening screws is an engineering disaster and the big weak spot in the PMX. I would prefer it did not have this "feature" (read liability).

Greg.

[marki]

Certainly sounds like a mount you would not want to import yourself, best buy it from one of the two local resellers.

[NilRecurring]

Greg, Stuart, Frolinmod, Joshua, CDKPhil, Graham and Paul,

First of all, thank you very much for the posts and the help. I would like your advice at this stage. I have done everything that Software Bisque has asked me to do:


Adjusted the RA camstop more times than I can count.
Centered the worm twice.
Adjusted the Spring Plungers to 2.5 turns and 3.5 turns.
Made a 95 pt. T-Point Model for Steve Bisque


I have at least spent a total of 30-40 hours trying to fix this $9000 mount, if not more. The ONLY thing that stopped the mount from stalling in RA was adjusting the spring plungers to 3.5 turns. This eases off the spring pressure and the mount functions normally - but I've found, today, that if the spring plungers are at 3.5 turns the RA axis develops about 1-2 mm of play. There is no play at 2.5 turns (I've done an A-B-A test), and the RA axis is rock solid but as I said, the mount stalls with that much spring pressure.

Please see a video here: https://www.youtube.com/watch?v=bR_G4ykPRQ8

My question is: what should I do now? Should I ask SB for a replacement? Is that reasonable at this stage? In my opinion, easing of the spring pressure doesn't actually solve the real problem it just masks the issue by easing off the force on the worm and it continues to track.

Mr. Patrick Wallace over at SB forums states that my T-Point Model is OK, and I believe him. I believe the issue develops after I wiggle the RA axis 3-4 times (before that, oddly, it's OK).

[frolinmod]

I agree with Greg Bradley's post above. The 3-way switch on the Paramount MX appears to be problematic. My Paramount ME, which does not have a 3-way switch, does not have these problems.

[Logieberra]

I agree with this comment, 'SB will come through but its probably going to take some patience'.

You've been real patient. Keep the faith :)

My question is, have they sent you any replacement hardware yet? Belts, worm block, new three position knob, MKS5000 control board etc? Considering this might be a gear mesh, friction and amp draw issue, I'd be real interested to know how a new worm block fares...

You need specialist advice for this one, and while the moral support from members here might help, despite their best intentions, I'd take the advice of non-MX owners with a grain of salt. They don't know the product and have no experience in dealing with SB. In time, SB will solve this for you, and you'll love the MX too :)

[NilRecurring]

No replacement hardware yet, which is why I'm asking I feel I've tweaked everything on this mount and I'm getting quite frustrated. I fix one issue and another pops up - I fixed the RA axis and it doesn't stall but as you can see from the video, there is significant play now.

Hence I'm asking for advice from MX or ME owners. Should I ask SB to send me a new worm block?

[Logieberra]

If you are based on Eastern Australia, you are welcome to bring the hardware over and compare with another MX side-by-side. Otherwise, someone closer might offer the same? We're here to help :)

[NilRecurring]

Thank you for such a kind offer but unfortunately I'm thousands of miles away in Pakistan.

[Logieberra]

Contact SB. Ask them to pair you up with another MX (or ME2) user in that part of the world. Buddy-up and see how that goes. Two heads being better than one and all that.

[NilRecurring]

There aren't any here, I'm afraid. I've asked around all the astronomy clubs so I'm stuck trying to fix someone else's mistake.

[frolinmod]

I guess only you and Steve Bisque can determine where to go from here. Shipping you a bunch of parts vs. shipping the mount back for repair/replacement/refund.

[gregbradley]

Fairs fair. I think you're close to needing to sending it back to them at their expense and they can do THEIR job and fiddle with it.

At what stage you have reached that point is up to you.

There was another poster here who had trouble and it was eventually detected and repaired ( a loose cable to the motor).

I would make a personal deadline for it to be sorted before it gets shipped back at their expense for in factory repairs/replacement. A certain amount of tolerance I think is workable in this pursuit as they are all small companies and boutique manufacturers. But it still was an expensive purchase and you are spending all your unpaid time debugging their faulty workmanship instead of imaging.

I think SB have had some terrible QC troubles with this mount. Lucky is the person who got one that worked straight out of the box. I am sure there must have been some.

I had some difficulty with mine but luckily minor compared to this. Once sorted though it is a spectacular performer and that is the carrot here.

Greg.

[NilRecurring]

Greg, thank you for your response. I don't even want to send the entire mount back, I think if they just sent me a new worm-block for RA it should fix this issue. The problem is now only confined to the RA axis and is really as simple as this:

1) Mount stalls with 2.5 turns worth of pressure.
2) Ease of the pressure at 3.5 turns and there is 1-2mm worth of play in the axis.

I've just emailed Mr. Steve Bisque and have explained the situation. I'm leaving on Monday for a business trip for 10 days so won't be able to tweak the mount anyway, if they ask me. What I'm hoping for is that they send out a replacement worm-block, and that it arrives around the time I'm back from my trip. I am hoping that all I have to do is install the new worm-block and just get on with my imaging.

I do believe someone here had an out-of-spec worm and he was sent just the worm-block and wasn't asked to send the entire mount back. I'm hoping that's how they treat my case because 1-2mm worth of play is clearly out-of-spec for this class of a mount.

[gregbradley]

They sent me a replacement worm block after mine developed a spike in PE that resulted in double stars.

The new block was easy to install (about 45 minutes or less) and it worked straight away.

Yes it seems the worm block is the critical component here that seems to be causing the most trouble. They must have had some QC issues with their supplier or in their workshop on these. The later ones seem good.

Greg.

[NilRecurring]

Yes, while I don't fully understand the inner workings of the worm-block it does seem simple enough: the motor drives the worm via a belt, and the block has a mechanism to put some pressure on the worm/gear via some springs. The block also has a mechanism to separate from the gear if there is too much force present.

My assumption (please correct me if I'm wrong) is that by replacing the worm-block I will be replacing the entire mechanism that drives the main gear so if there anything wrong with the RA axis (apart from the main 7.5" gear being damaged) a replacement should fix it.

Why I don't think it's the main gear: if it was, the problem would be far less frequent! The gear moves quite slowly, after all and if the mount stalls it shouldn't stall again for quite some time - but that is not the case. I can produce stalls within 10 minutes of each other.

[cfranks]

They sent me 2 worm blocks! Fixed my problem but it was not a difficult to diagnose / quantify as yours though.

Charles

[Logieberra]

True. A error in RA worm gear will show every worm cycle, somewhere between 2-3mins from memory. Issues with a out-of-round RA main gear would be less frequent, with many hours of imaging until you'd perhaps hit a 'high spot', if that is even the cause. We're just speculating here. SB will advise.