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Imaging With A Titan Mount

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#26 David Rosenthal

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Posted 07 September 2014 - 03:05 PM

Hi,

I may have found the problem but as it is cloudy I cannot check it out and maybe someone has the experience and advise me.

As the observatory is 50 meters from the house I use an extension lead to power everything in the observatory. A friend suggested that the cable is not man enough for the job and that the mount could be lacking in power.

I know a bigger cable is not that expensive but before I go and get one I wondered what you thought of this idea.

Thank you for your help.

Vince

50 meters is a long distance to run an extension cord if the gauge is too small.  Do you know what gauge the cable is?  The bigger the better and it can be a real fire hazard if it is significantly undersized.


Edited by David Rosenthal, 07 September 2014 - 03:06 PM.


#27 hungerford

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Posted 08 September 2014 - 07:57 AM

HI,

The gauge of the cable is 1.5mm.

Thank you.

Vince



#28 bill w

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Posted 09 September 2014 - 01:46 AM

vince

i feel your pain

as i struggled greatly to get two different losmandy mounts to track

was on the verge of smashing them on more than one occasion.

thought it took quite some time, by the time i sold my mount years later it had a very smooth PE with less than 2" peak to peak amplitude without any sort of PEC.

and yes, one was a bad ovision worm

 

where's the satisfaction if it's easy?

 

i'm not entirely sure i understand the problem

 

the point of the calibration step is simply to get the orientation for the autoguider

a little slop in that step is not the end of the world, you can still take images.

and guide

 

if i understand the first set of images, you are getting bumps when you actively slew the mount

the bumps when you slew the scope are more mysterious

particularly as there is none with a western slew. 

 

but what about tracking?

do the jogs occur when you are simply tracking on a star rather than slewing the mount?

 

what does it look like if you just run unguided on a star for the period of the worm gear?

try it with poor polar alignment so the star drifts

showing your periodic error.

 

sounds like you're a vet, but be aware that if your mount is balanced too perfectly, it will bounce around, particularly when slewing

 

what imaging setup are you using?

 

silly suggestions, but be sure the mount is set to titan in the gemini software

and be sure the guide rate is nice and slow, 1/2 sidereal at most.

 

the losmandy boards can be quite helpful...if they don't send you on a wild goose chase

scott losmandy is very friendly

 

PEM Pro can be helpful in tracking periodic error

but i'm not sure if the issue is PE or unusual jumps when slewing. 

 

 

addendum:

ok wait, it only happens when maxim moves mount...

just set your mount east heavy, dec balance good but not perfect, and polar align so you get slight dec drift

i think you may find it works better than expected

unless there are PE issues in addition to this


Edited by bill w, 09 September 2014 - 03:02 AM.


#29 hungerford

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Posted 09 September 2014 - 11:04 AM

Thank you for the reply. I will try to answer the question raised.

Thanks to an electrician who happen to come around due to a bad thunder storm I asked him to check my power supply in the observatory and hold and behold the power supply was totally inadequate for the observatory. I was using an extension lead and that was the problem. He now has installed a proper power line and I can calibrate in maxim without any more problem.

I have used Pempro to polar align the mount and I must say that I was very impressed with the result so I am going to purchase it. Previously I have been using AlignMaster who does a good job but Pempro is much more accurate. Again it is possible that I didn't use AlignMater properly.

The Goto is perfect and every object is dead in the centre of the chip.

The auto guiding is still giving me some issues. The RA is pretty good but the Dec is atrocious. I am trying to attach a Maxim Graph of the tracking to show what is happening and any advise on that would be a great help.

The Gemini is set to Titan 50 any of the other setting don't work so I am pretty show this is the right one.

vince

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#30 rgsalinger

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Posted 09 September 2014 - 01:49 PM

I'd like to see some screen shots of you Maxim DL settings.

 

I've been using it for years with no problems like this at all that could be attributed to MaxIM other than an infrequent "star faded" message.

 

You've clearly got a calibration problem and if the mount is mechanically OK, then I would look at the Gemini settings and other software to troubleshoot:

 

1. Ask the Ovision people exactly what drivers and software they used for the mount. I have this nasty feeling that you may need to reverse X and of Y based on what I'm seeing in your pix. Did they use YOUR hand controller?

2. Make certain that you're using a star near the celestial equator. Make sure all guider outputs are enabled and use 20 seconds to calibrate.

3. I would check the Losmandy (call them they are nice) and Ascom websites and see if there's anything there of interest -some setting in the Gemini or a later driver.

4. Estimate some numbers and enter them - I don't know the calculation but someone does. You can try guiding and see the error and increase/decrease until it gets small.

5. Also make sure that you've set the mount to 1x sideral if it has such a setting - I don't know Gemini but maybe the guide rate is set really low. 



#31 blueman

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Posted 09 September 2014 - 02:24 PM

Thank you for the reply. I will try to answer the question raised.

Thanks to an electrician who happen to come around due to a bad thunder storm I asked him to check my power supply in the observatory and hold and behold the power supply was totally inadequate for the observatory. I was using an extension lead and that was the problem. He now has installed a proper power line and I can calibrate in maxim without any more problem.

I have used Pempro to polar align the mount and I must say that I was very impressed with the result so I am going to purchase it. Previously I have been using AlignMaster who does a good job but Pempro is much more accurate. Again it is possible that I didn't use AlignMater properly.

The Goto is perfect and every object is dead in the centre of the chip.

The auto guiding is still giving me some issues. The RA is pretty good but the Dec is atrocious. I am trying to attach a Maxim Graph of the tracking to show what is happening and any advise on that would be a great help.

The Gemini is set to Titan 50 any of the other setting don't work so I am pretty show this is the right one.

vince

 Two things,

1) the DEC shows that you are oscillating positive to negative, so that could indicate too high of aggression in the settings. This could also be due to too much backlash in the DEC worm.

2) if the DEC worm was set too tight it could be grinding on the teeth. Also dirt in the grease can cause erratic graphs. How long has it been since the worm and wheel was completely cleaned and greased?

Blueman



#32 bill w

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Posted 09 September 2014 - 03:52 PM

congratulations on the find!

you're on your way

time to play with dec aggressiveness



#33 David Rosenthal

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Posted 09 September 2014 - 07:08 PM

Glad to hear the original issue issue was found and corrected.  That power extension smelled like the culprit to me!



#34 hungerford

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Posted 10 September 2014 - 04:41 AM

Hi,

Thanks for the advise.

I have clean and regreased the mount a few day ago and that did improved it a bit but I am still no getting the results I was hoping for.

I have played with the aggressiveness and basically what happen when I reduce it is the star drift further and further before the correction happen. So I am not sure as to what I should do.

I have reset the worm so as to have a little bit of play and I will need to test that out tonight as the forecast is good.

I have spoken to Scott at Losmandy and he was very helpful and I do appreciate his help.

Most of the initial problems have been sorted what I got left is to get the tracking going properly.

Vince  



#35 David Rosenthal

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Posted 10 September 2014 - 05:51 AM

If the star is drifting further and further in DEC that implies you have a polar alignment that is off.  The calibration lines show that there is nearly zero backlash in DEC or RA, the electronics and mechanics are sorted out, so it makes sense that the PA is the culprit.  Try taking a 10 minute unguided exposure of a star near the celestial equator and look at the drift.  If you PA is dead on , the star should be fairly round.  If it trails, the PA is off.



#36 hungerford

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Posted 10 September 2014 - 09:58 AM

I used pempro to do my polar alignment and on the pempro alignment graph over the 5 minutes it takes to travel the whole graph the drift is non existent so I assumed that the polar alignment was correct but may be I am wrong. 

I carried out the alignment twice on both axes.

However I and at latitude 46 degree north but the Titan mount is showing on the scale 51 degree north. I assumed that the graduation on the mount was incorrect but maybe not by that much.

The mount is perfectly level on both axes I have double checked that.

Thank you for your help

Vince



#37 rgsalinger

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Posted 10 September 2014 - 10:51 AM

I hesitate to post again since I was spectacularly wrong earlier in the thread - bad power causing calibration errors but perfect goto's is one for the books but................. 

 

Are you certain that X is the DEC axis? Do you have maxim set to graph the telescope - not the camera axes? 

 

This looks like some kind of backlash - if it's the dec axis - as it doesn't reverse directions when it should. I don't know the titan but if you can measure it, you can eliminate in Maxim pretty easily. Even trial and error with the backlash settings might get you somewhere.

 

What is the image scale of the guiding? If you're at a long focal length you may just be chasing the seeing. 

 

You can also get this from guiding when there are two stars in the track box - one dim that comes in and out with the seeing.

 

Rgrds-Ross



#38 hungerford

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Posted 12 September 2014 - 06:27 AM

Hi,

Many thanks to everybody who helped in trying to sort my Losmandy Titan out. Unfortunately it is not getting there so I decided not to bother anymore. This mount is obviously faulty and I am unable to get it sorted so I will revert to my trusted G11.

Thanks again for your help.

Vince



#39 blueman

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Posted 12 September 2014 - 11:28 AM

Hi,

Many thanks to everybody who helped in trying to sort my Losmandy Titan out. Unfortunately it is not getting there so I decided not to bother anymore. This mount is obviously faulty and I am unable to get it sorted so I will revert to my trusted G11.

Thanks again for your help.

Vince

 

I think you are missing something here. Perhaps you  are not mechanically inclined? There should be nothing that can not be corrected.

Blueman



#40 hungerford

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Posted 12 September 2014 - 01:20 PM

Hi,

I agree with you but there is nobody who can sort the problem out for me. I am prepare to pay whatever the cost would be to sort the problem out but even that isn't producing any result.

Thank you.

Vince







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