Processed this after Gary Palmers's demo today.

.

Target: Messier 31, The Andromeda Galaxy

Imaged and Processed by Wade Prunty with:
William Optics SpaceCat 51 APO Telescope
Explore Scientific iEXOS-100 Mount
Canon T3i DSLR
Optolong L-Pro Filter
William Optics UniGuide Scope
ZWO ASI120MM-S
ZWO ASIAIR Pro
95 x 300 Second Exposures
PixInsight
Topaz Labs AI Suite
--
Explore Scientific iEXOS-100
Explore Scientific EXOS2 PMC-8
Explore Scientific AR102
Celestron RASA 8
William Optics SpaceCat 51 APO
ZWO ASI294MM Pro
ZWO ASI183MM Pro
ZWO ASI533MC Pro
Canon 5D, T3i (Both Astro Mods)
William Optics UniGuide
ZWO ASI120MM-S
ZWO ASIAIR Pro

--
Regards,

Mario
Streetsville, Ontario

Mounts: iExos 100, Skyguider Pro
Scopes/Lenses: Main/Orion 80mm, DSLR/Tamron 18-400mm lens, guide/ZWO-340A
Computer: ASIAir
Cameras: Canon T2i DSLR, ZWO120MM (guide)
Utility Software: iPolar (for Skyguider polar alignment), iCap, Explorestars, Canon EOS Utility
Image Processing Software: Photoshop

Jdavis
--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired

Mario
--
Wes, Southport NC
EXos2-GT PMC-8, iExos 100
ES ED 127, 10" LX200GPS+wedge, Astro-Tech 8" Newt, ETX-90, 60mm no-name guide scope ~ 260mm FL
Polemaster, Orion ST-80 and SAG, ZWO 290MM, D5300 astro modified
Nina, Bootcamped Mac Mini control computer, RDP to iMAC
110 amp hour lead acid deep discharge battery for field power
Electrical Engineer, Retired

--
Regards,

Mario
Streetsville, Ontario

Mounts: iExos 100, Skyguider Pro
Scopes/Lenses: Main/Orion 80mm, DSLR/Tamron 18-400mm lens, guide/ZWO-340A
Computer: ASIAir
Cameras: Canon T2i DSLR, ZWO120MM (guide)
Utility Software: iPolar (for Skyguider polar alignment), iCap, Explorestars, Canon EOS Utility
Image Processing Software: Photoshop

--
Regards,

Mario
Streetsville, Ontario

Mounts: iExos 100, Skyguider Pro
Scopes/Lenses: Main/Orion 80mm, DSLR/Tamron 18-400mm lens, guide/ZWO-340A
Computer: ASIAir
Cameras: Canon T2i DSLR, ZWO120MM (guide)
Utility Software: iPolar (for Skyguider polar alignment), iCap, Explorestars, Canon EOS Utility
Image Processing Software: Photoshop

the iexos-100 is really a fantastic mount and if you manage to fit the snap before the flexion it follows really well but this is a big problem, the flexion writes with times of 10sec., with the replacement of the defective parts it becomes really perfect, it is really a pity and above all a nuisance.

On Sat, Oct 3, 2020 at 01:17 AM, Jerry Hubbell - Explore Scientific VP Engineering wrote:

Based on what I saw in the video, the end cap of the small pulley seems to be wobbling as you say, but again, we need to do a measurement to see if the pulley is actually not concentric on the shaft. The only way to do that is to use PHD2 and record a guide log to evaluate the true performance. Do you have a guide log I can evaluate?

I don't have a guide tube but the worst thing is that the worm also oscillates more than the pulley, if you see the video well you can see and that's what creates the oscillation of everything, in the case of the pulley the pinion is straight in the case of the screw endless is that which is wrong.
what you need is an endless drive and a straight pulley, in DEC it's all straight.

On Fri, Oct 2, 2020 at 03:07 PM, <salvo.semi@...> wrote:

yes it would be a solution but i don't like having a defective mount, i paid for a working mount and not working only partially.

Hi Salvo,

Based on what I saw in the video, the end cap of the small pulley seems to be wobbling as you say, but again, we need to do a measurement to see if the pulley is actually not concentric on the shaft. The only way to do that is to use PHD2 and record a guide log to evaluate the true performance. Do you have a guide log I can evaluate?

Thanks
 
--
Jerry Hubbell
Vice President of Engineering
Explore Scientific, LLC.
jrh at explorescientific.com
www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating
Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

yes it would be a solution but i don't like having a defective mount, i paid for a working mount and not working only partially.

Hi Salvo,

I would caution you to not jump to conclusions as the only way to really understand the impact of the pulley, which we have investigated a lot, is to get a guide log from your system. By analyzing the log we can see if the expected pulley related PE shows up in the periodogram at 133 seconds and 13.3 seconds. I can guarantee you that the mount is not defective in show PE in unguided images. It is not related to the pulley but the worm. Until we have a guide log that corrects the mounts tracking rate, I would not assume that your problem is related to the pulley.

The mount is not defective when displaying its native PE. These mounts must be used with an auto guider to get the best performance while imaging.
--
Jerry Hubbell
Vice President of Engineering
Explore Scientific, LLC.
jrh at explorescientific.com
www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating
Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

yes it would be a solution but i don't like having a defective mount, i paid for a working mount and not working only partially.

Yes, ultimately I would like to replace my pulleys as well, since both my DEC and RA had substantial runout.  Unfortunately as far as I know the parts simply aren't available.

While in an ideal world, both the DEC and the RA pulleys would be 100% perfect, however if your DEC is straight and in good condition,  it makes sense to put the straight pulley in the RA position since the RA is constantly moving while imaging.  The DEC, especially when unguided, will just be sitting still.  Periodic error on the DEC wouldn't cause egged stars.

Good luck,
-Tony

hello, yes the dec is straight, and I made sure that it is only the toothed part wrong, the thing would be easy to solve as long as they provide the replacement pulleys, it is a piece that costs very little, despite being mounts under warranty and the apparently defect is not single, when I run AR you can see that it is decentralized instead the dec is perfectly straight. I would like my mount to be straight both AR and Dec

Hello and welcome -

As already mentioned, guiding may go a long way towards reducing your errors. While some more expensive mounts may offer lower periodic error and produce better photos unguided, these mounts really benefit from guiding.  That would be my first suggestion. 

I have, however, experienced a similar issue as yours, even with guiding.  I would see a large error introduced to the RA axis every 133 seconds, which indicates it could be an issue with the pulley.  It sounds like yours may be the same. 

It is still unknown if the cause of my tracking/guiding error was due to the pulley teeth themselves being eccentric, or if it was a problem with the sidewall / belt keeper rubbing the belt.  Either way, one of the first troubleshooting steps ES had me do was to swap the RA and the DEC pulleys to see if the problem subsides, since the DEC is not prone to periodic error like the RA is.  You'll also want to make sure your belt tension is correct, and it is not tracking off to one side.  Hopefully your DEC pulley is straight enough that it solves your problem. 

Ultimately, those suggestions did not do much to help my situation, and my oval stars persisted even with guiding.  I have looked high and low, but have been unable to find a suitable replacement pulley.  As far as I can tell,  you would be looking for a 10 tooth GT2 type pulley with a 5mm bore.  If you happen to find one available online, please let me know.  I would love to purchase a replacement as well.

Good luck with your mount and your imaging,
-Tony

as regards the focal it takes place in all focal lengths

hello, thanks for the quick response, I shoot without a guide, the problem is that not all the photos are elongated but on average half, and when that gear turns you can see that it is twisted and pulls and loosens the belt, this cmq is not good, in my opinion it would solve by putting the gear straight so that the belt always has the same tension. I would also be willing to buy it knowing the measurements and the number of teeth, it does not have an excessive cost.

Hi Salvo,

Welcome to the forum!  

What focal length are you imaging at? Are you autoguiding? If you are using PHD2, can you post the guide log for us to take a look at?  If you are not autoguiding then the oblong stars are related to the inherent PE of the iEXOS 100 mount system. Depending on the focal length you are imaging, you can get away without auto guiding, but you will always have some sub frames that show elongated stars. If you could post one of your images also, that would be good.

Thanks
--
Jerry Hubbell
Vice President of Engineering
Explore Scientific, LLC.
jrh at explorescientific.com
www.explorescientificusa.com
1010 S. 48th Street
Springdale, AR 72762
1-866-252-3811

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home


Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
Mounts: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating
Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

hi all, i have an iexos-100 and i noticed that taking pictures half come with elongated stars and half not, more or less at regular intervals. I tried to figure out what the problem was and I realized that the gear of the pulley of the AR motor is slightly crooked, so there are moments that stretch the belt and it could cause those micro movements that cause the stretched stars, see photo gear, I wanted to ask cove I can find this gear or at least the measures and how many teeth it has so that I can buy and replace it, the frame is still under warranty. P.S. sorry english but i used google translate.