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NOW AVAILABLE! Our New Explore Scientific iEXOS 100 PMC-Eight $399

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681 replies to this topic

#676 Devonshire

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Posted Yesterday, 12:20 PM

Dubbelderp,

 

Yes, there's an ES-produced video on iExos-100 gear adjustment, although I don't have the link handy.  The other thing you might look to is your balance.  Quite apart from the usual east-heavy recommendation, you may also want to be camera-heavy.  



#677 DubbelDerp

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Posted Yesterday, 12:48 PM

Dubbelderp,

 

Yes, there's an ES-produced video on iExos-100 gear adjustment, although I don't have the link handy.  The other thing you might look to is your balance.  Quite apart from the usual east-heavy recommendation, you may also want to be camera-heavy.  

Thanks! I think I found the link. I did have the mount slightly camera-heavy, purely by accident. The two counterbalance weights at the end of the counterbalance arm were just slightly not enough weight for the scope and camera.



#678 DubbelDerp

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Posted Yesterday, 12:52 PM

I would try not for a spot on PA and guide DEC in on direction, works great with my CG-4

 

attachicon.gifCapture eq3=cg4.PNG

Yeah, PHD2 told me I was pretty far off in guiding assistant. I did try to guide DEC in just one direction, and that's when it started wandering off in declination. I let it go that way overnight, just to see what would happen. 

 

I think the calibration looks a wee bit off...

 cal.PNG



#679 zxx

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Posted Yesterday, 12:55 PM

Yeah, PHD2 told me I was pretty far off in guiding assistant. I did try to guide DEC in just one direction, and that's when it started wandering off in declination. I let it go that way overnight, just to see what would happen. 

 

I think the calibration looks a wee bit off...

 attachicon.gifcal.PNG

Ouch, 



#680 Jerry Hubbell

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Posted Yesterday, 01:43 PM

I picked up one of these little mounts a few weeks ago as an "upgrade" for my Skyguider Pro. I like doing widefield mosaics, which can be a bit of a challenge with manually framing a target and trying to line up one panel to the next. This seemed like a good fit, since it would allow some more flexibility to align things with platesolving and goto.

 

Coming from a completely manual system, I haven't had any experience with ASCOM or driving a mount from a laptop. After installing various software (Stellarium, ASCOM platform, ASPS), I was surprised how easy this was to connect over USB to my laptop, and soon had it talking to Stellarium and ASPS. Cool! I could load a panel from a previous night, platesolve it, and goto the location, at least from the comfort of my living room.

 

I finally had a chance to try it in the field last night. All the software connected and talking, everything looked good. The polar alignment tunnel wasn't all that bad - I used my phone to roughly aim the mount north and used the angle finder to set the altitude. Took a peek through the tunnel, and Polaris was right there. I didn't bother trying to refine it beyond that, since I wanted to see how it would perform with a rough polar alignment. Manually aimed my scope at Navi in Cassiopeia, took a picture, platesolved it, and synced the mount to this location.

 

From there, I had it slew over to Gamma Cygni, loaded PHD2, calibrated, and took a 300-second exposure. Star trails. I figured it wouldn't all go smoothly the first time out, and this is where I started running into problems. I ran guiding assistant for 15 minutes or so, measured backlash, and applied all the recommendations. Took another exposure, and the trails are even worse. It appears that PHD2 isn't able to keep the declination axis under control, as the trails are oscillating back and forth in DEC. Since it was already set up, I had it run overnight to see how it would perform. It looks like I get a half dozen or so subs with egg-shaped stars, and then it starts wandering all over the place for another half dozen subs. I don't think I got any "good" subs, but lots and lots where the mount just appears to wander off in declination.

 

I think I saw some links for how to adjust the gears to reduce the amount of backlash earlier in this thread - I'm going to go hunt these down now. I'm using a 60mm f/6 doublet refractor that's nicely balanced, so I don't think I'm exceeding the capacity of the mount. Any suggestions for where to start troubleshooting the tracking issues?

 

All in all, I think this is a pretty decent mount for the price, and was surprised how easy it was to get it connected to my laptop... I just hope I can figure out why I can't get good guided photos!

Hi,  I would suggest a couple of things. First, we have a lot of customers using the mount out of the box with PHD2 without having to adjust the DEC lash, so I wouldn't immediately jump to that without ruling out a few things first. It would be good to use the mount as suggested with a "not-so-perfect" polar alignment so that PHD2 can drive the DEC axis in one direction as suggested. This should help. Also, I would invite you to join the Explore Scientific PMC-Eight Groups.io forum as there you can interact directly with our customers who have a lot of experience using the mount in the field. You can join at:

 

https://espmc-eight.groups.io/g/MAIN

 

Please post your issue on the PMC-Eight forum, I think that we can get your problem resolved pretty quickly.

Thanks for your purchase!



#681 DubbelDerp

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Posted Yesterday, 03:06 PM

Thanks Jerry! I actually did register there a few weeks ago. It's not the most user friendly site... but I'll give it another go. I'll give the mount another try to see if I can get a clean guiding log first. In reviewing the log, it looks like I kept loosing the guide star for some reason, so I'll investigate that first. I'm not sure what to make of the calibration results I attached above, though.

 

Quick question on the clutches - should they be cranked down tight, or just tight enough to keep them from slipping?

 

Thanks, Todd



#682 asanmax

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Posted Yesterday, 03:30 PM

Thanks Jerry! I actually did register there a few weeks ago. It's not the most user friendly site... but I'll give it another go. I'll give the mount another try to see if I can get a clean guiding log first. In reviewing the log, it looks like I kept loosing the guide star for some reason, so I'll investigate that first. I'm not sure what to make of the calibration results I attached above, though.

 

Quick question on the clutches - should they be cranked down tight, or just tight enough to keep them from slipping?

 

Thanks, Todd

Hey Todd,

 

The clutches need to be tightened well to prevent any accidental slipping.

To your egg shaped stars...

First off, the mount can handle imaging at 1350mm of FL, I tried that and I was guiding with a 130mm guide scope.

I don't think that you are overloading the mount with your 60mm scope, I've run my mount with a total payload of around 3 to 4 Kg with no issues.

 

You can do a quick test to see if you have some backlash in both axes.

Tighten up the clutches well and try to move the scope in both axes back and forth. You'll probably notice some play but it shouldn't be too bad for good guiding.

 

Also, if you haven't done so, try to use drift align tool in PHD2. Just do a rough polar alignment and then run the tool. It will tell you what to do exactly. It will take you some time if you use the tool for the first time.

It takes me 5-7 minutes now even though the Polaris is not visible from my backyard. I never use the polar scope in my mounts.

 

Try to do calibration after that and then run guiding assistant to see if you need to adjust the numbers.




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