Re: Mach1 problem please assist

Christopher Erickson

I have seen it before where bad PEC data causes all kinds of guiding grief. The manual PEC training function in the hand controller, combined with a transient user was the culprit.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738

On Sat, Jun 20, 2020, 7:01 AM Ron Kramer <ronkramer1957@...> wrote:
GREAT NEWS ROLAND.  I'll do some PEC options next time.  Bumbed I didnt remember last night but I was running two rigs and imaging on both  = (
2-3 nights I might get some stars. (but amazed we just had 6 clear nights in a row). 
I'll report back with PE tests

On Sat, Jun 20, 2020 at 12:23 PM uncarollo2 <chris1011@...> via <> wrote:
Yes, that shows exactly what Andrew discovered when he analyzed your logs. The good news is that it is NOT a mechanical problem. Your geartrain is fine. It is almost certainly a rogue move command coming from either the PE memory, or from some other outside software.

Disconnect all outside software and just let the mount run with PEM turned OFF. Initialize the mount as you normally do, but then yank the connection between your computer and the mount controller (after acquiring a guide star of course). The mount will continue to track at the sidereal rate even with everything disconnected. Let PHD2 simply monitor the motion of a guide star for a period of time. If the same motion persists with no outside software connected, then it is coming from inside the CP controller (either PEM rogue data or a software malfunction). We can easily check the controller here, no need to send the mount in.


-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Sat, Jun 20, 2020 11:10 am
Subject: Re: [ap-gto] Mach1 problem please assist

SHOOT I did some tests last night and tried lots of things but forgot to try  PEC  off.   I'll try next clear night.  DANG IT. 

I did turn off guiding though for a bit in the middle here.  So look at PE on this capture, Is this ANY CLUE? 


On Sat, Jun 20, 2020 at 11:28 AM uncarollo2 <chris1011@...> via <> wrote:
Andrew Johansen analyzed your logs and it appears that the problem is not caused by any worm issue or other mechanical defect. It appears that the mount receives a 10 arc second move command and then PHD2 immediately corrects it to bring it back to the zero line. Thus it appears as a spike instead of a continuous move command in one direction. It would have been easy to see the actual motion if the guide pulses had been disabled, and then we would not have been chasing the mechanical red herring down the blind alley.

So, no need at this point to send your mount back here.


-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Fri, Jun 19, 2020 2:33 pm
Subject: Re: [ap-gto] Mach1 problem please assist

I'll check PE. But after cleaning I did a  "record" and it finished so I suspect it recorded a clean PE. 

I REALLY hate sending in the whole thing.  But would be nice to get it all tweaked. (PHD reports a good amount of backlash (not sure if its true)  It always has since new. The backlash graph is always off a good amount. I just ignore it. 

On Fri, Jun 19, 2020 at 2:19 PM uncarollo2 <chris1011@...> via <> wrote:

By the way, is it possible that you have PE correction turned on and you are playing back some bad data? We had this happen once on a mount at the Mauna Kea visitor center. Someone had manually entered a huge correction curve into the PE memory and was playing it back. Caused the mount to jump every worm cycle.

If this is not the case, then the mount needs to be sent in for evaluation. I can look at it the moment it arrives. Also send the cables and CP controller too, in case something is weird there.


-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Fri, Jun 19, 2020 10:02 am
Subject: Re: [ap-gto] Mach1 problem please assist

Next night - I'll do a 2-3-4 worm cycle unguided.  I also may have one in a older log. I'll work on that. 


On Thu, Jun 18, 2020 at 9:22 PM uncarollo2 <chris1011@...> via <> wrote:
One other thing that would be extremely helpful is if you ran the mount for about 2 worm cycles (about 15 minutes) with guiding effectively off so i can see what the worm is actually doing. Posting a guided graph hides a lot of stuff that makes it hard to do actual trouble shooting.


-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Thu, Jun 18, 2020 5:57 pm
Subject: Re: [ap-gto] Mach1 problem please assist

I'll post then then try groups interface.
I logged out my best guess on each incursion.  There are no seconds so I had to estimate.
This would be the later set of errors that kicked UPWARD

about  12:38.55 sec
about  12:45.20 sec
about  12:51.50 sec
about  12:58.10
about  01:04.40
about  01:11.05
about  01:17.25
about  01:23.50 sec
about  01:30.15 sec

looks like they're spaced 6 min  20 seconds about.   That's about a worm repeat? 

On Thu, Jun 18, 2020 at 6:50 PM Liam Plybon <liam@...> wrote:
I believe you may have better luck by using an image hosting server and posting a link.
Groups is set to compress images automatically after complaints by users with slow or expensive internet who would have to download large images each time one was sent on the group. Especially here, where we all love sharing massive astro-images that can gobble up bandwidth.
From: [] On Behalf Of Ron Kramer
Sent: Thursday, June 18, 2020 17:40
Subject: Re: [ap-gto] Mach1 problem please assist
Yep - one continuous run. Not near the meridian.  I'm attaching pics in email. It asks original, best fit etc.  Upon appearing it's a small little blurry version.
would it make them more clear if I enter the post in the groups interface and not in email?   These are BIG ANC CLEAR AND SHARP when I attach them.

dental in shape when zooming in.
On Thu, Jun 18, 2020 at 5:11 PM uncarollo2 <chris1011@...> via <> wrote:
The graph shows 7 RA motions in the down direction, then a number of RA moves in the opposite direction. Is this over a period of time continuously? In other words, was this graph taken without interruption?
-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Thu, Jun 18, 2020 3:42 pm
Subject: Re: [ap-gto] Mach1 problem please assist
Capture is CLEAR and sharp. not sure what "GROUPS" does to images. I hate GROUPS.  Forums are better and allow you to retain/library of topics and Q&A, = (
I'll attach it again.  Is there a limit? size? restriction?    I'll attach at ORIGINAL SIZE

On Thu, Jun 18, 2020 at 4:37 PM Ron Kramer <ronkramer1957@...> wrote:
I don't own use a keypad.   I did try that SWAP OVER - but I then cleaned it and not sure where it ended up.  Since the last test clearly had the saime  KICKS. I can do ig again.  
What does that do?  I think it might track toward the other side of the groove?  I'll swap it over again and see if it helps since re-greasing.

NICELY - greasing lowered my RA RMA error almost 50%.  Here is my history.

Mount arrived. I guided around 1.0.  Always trying to tweak it - not sure why but months later I was guiding at  .24 RMS error (arc set). yeah - that's awesome.
MANY months of that... The RASA guided better than my long APO.  But late winter I swapped RASA V1 for a RASA V2 (heavier) and ever since my guiding was 1.5 average.  My image scale is 1.69 
lately - the RA kicks put me into  1.7-2.0.  I get double stars on every other sub. 
I re-greased the RA and last night afterwards I was 1.1max and usuall around .89 tot rms arc sec. (nice)  But the RA still kicks and makes for double stars.  My dec was still poor so I'll regrease dec next and check
my alignment. (it's fairly perminent in a dome, but I have a tripod leg/mount and it "can move".  I usually check alignment 1-2 times a year or when ever guiding quality decreases. 
I am not aware of any gear scraping - I always release it clean...  I have on 3-4 occasions allowed it to track into a leg and (stop). Not sure if that hurts anything. But seems to work fine next time.

I don't understand why the RA kick changed from lower to higher (E to W?) the mount orientation did not change. 
I'll swap the part positions over and try again tonight.  During regreasing/cleaning I saw nothing strange. No chunks or crud.  old Grease moved quickly,  freely. not at all gummy. 
I have some pics n video.
On Thu, Jun 18, 2020 at 3:39 PM uncarollo2 <chris1011@...> via <> wrote:
Hello Ron,
Howard won't be able to answer you at this time.
Can you do a test for me?
With keypad in Autostart NO, send the mount to Park1 and turn off power.
Loosen the clutches and move the mount to Park5 manually.
Turn power back on and press "Resume from Park5"
Now check to see if the RA anomaly persists. let me know the results and we can go from there.
By the way, your screen shot is so blurry I cannot make out any details on it.
-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Thu, Jun 18, 2020 1:35 pm
Subject: Re: [ap-gto] Mach1 problem please assist
I re-greased the RA.  It was really relaxing and nothing to fear.  No springs jumped out at me or other crazy surprises. 
The first test last night showed my RA improved by almost 50% reduction in RA RMS error.  (I'm shocked).

On the bad side, I did not fix my RA KICK problem.  I did not see RA worm flaws except on the very end (3 turns) of the worm and I'm sure that is never in contact with the drive gear.
I have emailed Howard... but wondered if it helps determine the problem from last night's guide log.  I was surprised to see it FLIPPED the RA kick.  (no meridian flip took place) why would it flip? 

On Wed, Jun 17, 2020 at 4:21 PM Ron Kramer via <> wrote:
Kit arrived late last night. (UPS error)
Today it was hot in the dome so I just did the RA worm and drive gear. And the side gears)
I hope to test tonight and see if it solves my RA kicking problem. 

I inspected the worm and was in fine shape - EXCEPT I had some very rough area which I don't think matters. It was way over on the very edges of the worm... like the last 2-3 turns were rough. I don't believe this are ever used? 

I greased the entire worm even though it said just the center is all that's needed. Figured it would help ward off corrosion.   The process wasn't scary once the RA box was removed. In fact (I don't recommend this) but I didn't even take my gear off the mount.  RASA 11 + essentials upside down at times.   I forgot about the cords but never turned more than 180.  I actually read the instructions after I was done. (common for me, I like to dig in) then see what I did wrong. 

SOUNDS nice... Will see if the RA hiccups tonight in a guiding test.  if all is good I'll do DEC tomorrow but RA was a primary concern as it would jump and killed every other sub.

Will see tonight.

On Wed, Jun 10, 2020 at 4:33 PM Marj Christen <marj@...> wrote:
Now that our production staff has returned, the turnaround time for repairs is pretty quick. There is no standard cost for a “ tune up” since it depends on what is involved and if parts have to be replaced.
Try regreasing first and contact us again if you can’t resolve the issue.
Clear Skies,
Marj Christen
Astro-Physics, Inc
11250 Forest Hills Rd
Machesney Park, IL 61115
Phone: 815-282-1513
Fax: 815-282-9847
From: [] On Behalf Of Ron Kramer
Sent: Wednesday, June 10, 2020 1:33 PM
Subject: Re: [ap-gto] Mach1 problem please assist
I'm about to try to re-grease - I'll see if I can see something during inspection.  Is swapping the worm something easy I can do at home? 
I don't want to do anything complicated. I don't believe I've nicked a gear - I only use park3.  But it has come against the pier during a few 3-4 occasions? Would that do anything?

How much does it cost to send it in for a tune up?  HOW LONG would I be without it?  I'm near in Grand Rapids, MI.
I'll look for a clump of anything in the worm teeth.  If I send it in I don 't want it waiting for weeks/days. What is time frame? 
I ordered the grease, I'll see how that goes.
On Tue, Jun 9, 2020 at 7:51 PM uncarollo2 <chris1011@...> via <> wrote:
Forget backlash in RA. There is no such thing. RA always tracks so it never reverses. Backlash does not enter into tracking.
You may have damaged your worm teeth when you backed off the worm to do a fine balance. You may have forgotten to do it only in the Park3 position. If that's the case, the worm may have a nick in the teeth and it will show up as a repeating pattern once every 6.4 minutes.
-----Original Message-----
From: Ron Kramer <ronkramer1957@...>
Sent: Tue, Jun 9, 2020 3:30 pm
Subject: [ap-gto] Mach1 problem please assist
My mach1 is about 2.5 years old.  I was getting awesome guiding with a total rms error of .24 arc sec.  
Winter came and went and this spring it's been horrible.  like  1.4.   My image scale is about 1.69 so I lived with that for a while, but lately
the RA is  KICKING in almost a timely fashion.  One of these kicks makes double stars.  Around 1/2 my subs have to be deleted.
Nothing I have tried to far has fixed it.
I will include the log from a couple nights ago to show what I mean. 
I did a new calibration - then a guide assistant for a while... then set recommendations and let it guide a while.
You'll see   RA  kicking like a mule in a rather evenly timed fashion!?!  
I would so appreciate help with this.  Someone in PHD said make sure the mount software/HC doesn't have backlash on.  
I DO NOT USE or own a HC and I don't know of any BackLash setting in APCC pro.  I'm going nuts. 












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