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  #21  
Old 19-02-2014, 08:55 PM
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TR (Terry)
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I have an AP mount. The thing just works. It is the only thing that never faults. When I take it bush, it takes about 20 min to get it spot on pole using PEM Pro - included. I do this a just before sunset, and finished before the guys can use their polar scopes. The trick is to get it within a few degrees of pole with a compass, and use Pem Pro to dial it in. Or, you can use the daytime alignment function explained in the manual. I use the Keyspan USB to serial adapters - they work perfectly.

Terry
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  #22  
Old 19-02-2014, 09:07 PM
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Originally Posted by Logieberra View Post
Thanks Ric

Also, I keep reading that balance doesn't matter. The motors just power through?

Cheers.
Somewhere I read a statement by Roland that went something like "try for balance, but don't stress about getting it perfect"

Worst thing about an AP mount is that you get bored watching a flat line guiding graph. Doesn't provide the excitement my Losmandy G8 did.
Geoff
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  #23  
Old 19-02-2014, 09:12 PM
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I'm several Kg over spec on the AP900 and it doesn't mind if the balance isn't perfect.

Cheers,
Rick.
How much over spec Rick? I wanted to mount my Televue 101is and 12.5" Plane Wave side by side and George (from AP) suggested it wasn't a good idea. However, Roland didn't seem fussed about it when I raised the matter on the AP Yahoo forum.
Geoff
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  #24  
Old 19-02-2014, 10:23 PM
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How much over spec Rick? I wanted to mount my Televue 101is and 12.5" Plane Wave side by side and George (from AP) suggested it wasn't a good idea. However, Roland didn't seem fussed about it when I raised the matter on the AP Yahoo forum.
Geoff
Geoff,

My Ceravolo/U16M set up weighs in around 37 Kg or so vs. the 31.8Kg capacity in the manual. I had to get a longer counterweight shaft and a few extra weights but the mount handles it with ease.

Cheers,
Rick.
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  #25  
Old 20-02-2014, 07:59 AM
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RB (Andrew)
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Worst thing about an AP mount is that you get bored watching a flat line guiding graph. Doesn't provide the excitement my Losmandy G8 did.
Geoff
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  #26  
Old 20-02-2014, 08:16 AM
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multiweb (Marc)
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Worst thing about an AP mount is that you get bored watching a flat line guiding graph. Doesn't provide the excitement my Losmandy G8 did.
Geoff
I can come and boot your pier on demand to keep the blood flowing. Or maybe you want to swap? You won't get bored. Guaranteed.
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  #27  
Old 20-02-2014, 05:04 PM
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Followed Ric's advice and downloaded the 1600GTO manual. Just read the RA/Dec gear meshing chapter, if you could even call it a chapter! Essentially: loosen three screws, then tighten them. Wow!!! I love this mount already!!!
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  #28  
Old 20-02-2014, 05:23 PM
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I did have an issue with mine parking in weird positions - turned out I was using an old version of the ASCOM driver. Not sure where I had downloaded it from, but the latest one works perfectly.

DT
AP mounts seem to revolve around this central 'Park' concept. Can you demystify it? And what's this new Park 4? Coming from a MX, w' start up homing in both Dec and RA, software programmable park positions in SkyX, and very repeatable pointing night after night, I was spoilt...

Mainly, does starting from a pre existing AP park position guarantee the same superb, repeatable pointing; subject of course to underlying modeling, accurate site data, PA and all that, without the need to Recalibrate each time?

P.S. When the 1600 homing/limit switch system is available, I'll jump on that. For now, the 3600 H/L system gives a good indication of what it may include: http://www.astro-physics.com/product...t-switches.pdf

Last edited by Logieberra; 20-02-2014 at 05:34 PM.
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  #29  
Old 20-02-2014, 07:50 PM
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Originally Posted by Logieberra View Post
AP mounts seem to revolve around this central 'Park' concept. Can you demystify it? And what's this new Park 4? Coming from a MX, w' start up homing in both Dec and RA, software programmable park positions in SkyX, and very repeatable pointing night after night, I was spoilt...

Mainly, does starting from a pre existing AP park position guarantee the same superb, repeatable pointing; subject of course to underlying modeling, accurate site data, PA and all that, without the need to Recalibrate each time?
Essentially yes!

Once polar aligned and synced to the sky, I park the scope at night and the next night just unpark it and slew to the target. I don't bother with modeling as my setup is temporary - pointing is usually accurate enough for plate solving in Maxim with pinpoint LE. Accuracy after a meridian flip is obviously dependent on how orthogonal your OTA is to the RA axis.

I don't believe this sort of behaviour is exceptional when compared to other mounts, but it's definitely reliable.

DT
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  #30  
Old 20-02-2014, 09:02 PM
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I have an AP mount. The thing just works. It is the only thing that never faults. When I take it bush, it takes about 20 min to get it spot on pole using PEM Pro - included. I do this a just before sunset, and finished before the guys can use their polar scopes. The trick is to get it within a few degrees of pole with a compass, and use Pem Pro to dial it in. Or, you can use the daytime alignment function explained in the manual. I use the Keyspan USB to serial adapters - they work perfectly.

Terry
Terry, I look forward to using that Pempro2 PA feature. I think I read somewhere that it's like 'drift alignment on steroids!' It's a real time, on screen, iterative adjustment process isn't it? I'd like to use my STi if possible, via MMOAG pickoff prism.
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  #31  
Old 21-02-2014, 09:58 AM
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Yes, it's like a drift alignment on steroids. I made a cheat sheet of instructions located on my desktop that helps me dial it in quickly. It has stuff like to move mount west in Az, turn knob X. I also have what each graduation represents on the adjustment knobs. The exact measurements of what the short and long marks represent are in the AP manual. I have the same for Altitude adjustments, ie, to lower mount, turn Alt knob clockwise. Again, the graduations are in the manual. The graduations are so accurate, that if it says to move mount west 10 arc min in Azimuth, then I move it just short of the mark and measure again. I find that if I shoot for just 2 arc min short, the graph usually says, you need to move it another 2 arc min. I prefer not to overshoot. It only takes me a couple iterations to hit the mark. The cool part is one you hit 0 Ė and nothing moves, you are spot on pole. Itís a good feeling

A few tips, wait about two min to get an accurate measurement on the graph. Restrict your dancing around the mount with joy, because you will pick that up in the graph. Write stuff down and create a cheat sheet of instructions, so when you go remote, polar alignment is an easy 20 min job. I always have the camera in the same orientation on the scope for polar alignment. The calibration routine creates star trails at first to determine your camera angle and image scale. You can use these trails to determine if you are way off pole buy the orientation of the star trails across the frame. Consistency is good thing for this task. Once you have been through it a few times, it really doesnít take long at all.
I use my STi as a guide camera, but with a small guide scope. Works well. Having a shutter on a guide scope is great.

Terry
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  #32  
Old 21-02-2014, 10:39 AM
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Terry, it sounds fantastic. Drifting stars don't lie. Other software programs, with intricate PA routines, have so much going on in the background, that I'm often left wondering - can I really trust the software calculated PA recommendations...

Also, I'm guessing that your PA can be off by heaps with this program? You'll just see massive drift, in real time?

P.S. I'll look into the daytime routine, to bring it somewhere close to PA to begin with.
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  #33  
Old 21-02-2014, 10:46 AM
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Daytime routine is great to approximate altitude, but doesn't help with azimuth.

DT
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  #34  
Old 21-02-2014, 11:20 AM
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Daytime routine is great to approximate altitude, but doesn't help with azimuth.
I usually get a rough azimuth by pointing at the Sun and sighting down the outside of the scope (optics covered, of course...)

I used to use Pempro for polar alignment but these days I use PoleAlignMax which I find quicker. It uses plate solving and slewing to calculate the alignment error. The only thing I don't like about it is that it still points you at the J2000 pole so I have to use a spreadsheet to compensate.
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  #35  
Old 21-02-2014, 04:24 PM
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One word of caution, if you are too far off pole, wacky things will happen. To avoid this, I use a compass and take into account the magnetic offset to the pole. That way, Iím pretty close before I begin. Anything less than 5 degrees has worked well for me. Over 10 degrees and stuff just doesnít seem to make sense. I line up on the pole and lay a piece of wood or alloy channel on the ground pointing to the pole before I move any big steel bits nearby. I canít trust the compass once everything is around me. I then set up over the stick being careful not to bump it, and remove the wood after setup. From here, I check my GPS and set my alt angle with my tablet. Now youíre ready for twilight, just as you see the first stars visually. Pempro will lock on stars at this point, and you have a good starting position.

If you have a look in the manual, Roland (Mr. AP) uses the daytime alignment technique, and fine tunes with Pem Pro. Before PemPro, it was hard. Tried all the stuff everyone mentions in the forums. This method has worked for me. I think the main reason is knowing how to translate the graduations on the adjustment knobs to how far PemPro reports you are off pole. I tried it with a Vixen GPDP and it drove me nuts. Did not know how far to turn the Alt / Azimuth adjustments. I was always wrong and it was truly just a guess. Frustration would be an understatement. With the AP Mount, that all changed. Itís almost like it was made for it.

Terry
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  #36  
Old 23-02-2014, 02:28 PM
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I've used PEMpro to drift align my MX and it is a very nice aid. But to say one is "spot on the pole" is not exactly correct as there is no such thing. There are various "poles" depending on what one wants to do and where one images in the sky (refraction), etc. It seems that all polar alignment is a compromise.

Now, with my MX (perhaps partly because of the issue it had with the polar axis) I had various difficulties with the T-Point polar alignment recommendations.** But, suffice to say, if one is close enough to PA, T-Point will do the rest regarding tracking corrections and will deal with flexure and mount inaccuracies (if repeatable). Anyway, the critical thing is that once PA is set, and a T-Point model constructed it is not OK to move the PA unless one re-calibrates back into the model and reestablished the ME and MA terms. (To do that one re-calibrates as a portable mount even if the mount is permanently set up.)

What I like about the PEMpro routine is that it gives a no drift situation at and near Dec = 0 which may be in the region of the sky where one wants to image. I personally found it faster to use than T-Point (for PA) as it doesn't need multiple iterations. It seems to be a reasonable compromise for PA and a reasonable PA to start a large T-Point run from. This is what I've done. I just ignore the PA report from T-Point once I'm happy with the PEMpro result. The large T-Point run then will give terrific pointing and excellent tracking.

Logan, are you still intending to use TSX/T-Point with your AP mount or are you changing all?

Peter

** In my experience T-Point can give some vexing results if one's view is restricted east or west. Mine is very restricted to the east but unrestricted to the west. Even though I collected points on both sides of the meridian there were far more points to the west. This seemed to skew my PA recommendations strangely. If I restricted collection of points to be equidistant E and W of the meridian I ended up with a polar alignment that was pretty close to the PEMpro drift alignment. I'm sure there could be a multitude of factors at play here so it is difficult to draw a conclusion from this. I will just say that given my conditions, and my particular MX this is what worked best for me.
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  #37  
Old 25-02-2014, 05:22 PM
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Thanks Peter.

After full on, high end robotic control of the MX via TSX and CPU, I'm interested in going back to basics for a season. The brains of the AP, the GTOCP3, are fully controllable from the supplied hand controller alone. It's a rugged unit, military spec and reaches deep into mount control settings, e.g. the user can turn PEC on or off from there.

I would also like to utilise the (free) AP software supplied with mount before returning to the SB subscriptions. I do love TSX, so we'll see how long that can last!

Oh, and the upcoming APCC, AP's equivalent of TSX which includes their take on Pro-Track, with large pointing models which correct for flexure, refraction etc. I'm pretty sure that's a paid add on.

We'll just have to see...

Like you, I'm just hanging out for mount arrival!

Last edited by Logieberra; 25-02-2014 at 05:36 PM.
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  #38  
Old 25-02-2014, 05:27 PM
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Here, at 11:40 mins into the video they discuss the AP1600 encoders and a bit later they take a tour of APCC, if anyone is interested:

Watch "Astro-Physics at NEAF 2013 -- Sky & Telescope" on YouTube
https://www.youtube.com/watch?v=qBMB...e_gdata_player
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  #39  
Old 25-02-2014, 05:59 PM
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Terry, it sounds fantastic. Drifting stars don't lie. Other software programs, with intricate PA routines, have so much going on in the background, that I'm often left wondering - can I really trust the software calculated PA recommendations...

Also, I'm guessing that your PA can be off by heaps with this program? You'll just see massive drift, in real time?

P.S. I'll look into the daytime routine, to bring it somewhere close to PA to begin with.
Hi Logan, just seen this thread. What a great purchase. I love the control functionality of the AP mount, and do you notice how many threads exists where AP users have problems? Nope, rarely see any. As for Terry's comments, the notches on RA / DEC adjustment knobs are for "Pemming" the mount in. Doing two mounts at once in the field as sun set approaches, we are normally are done before you can see the Octans (15-25mins for both, 1 arc min or less). By the way, this not done with the OAG, but your main camera.

Doing automation with the AP is also great, with it understanding all standard command instructions issued by executive program's like CCDAP. Meridian flips just happen when instructed, and thats just great.

You will love it.

Steve
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  #40  
Old 26-02-2014, 02:41 PM
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Hi Logan,

Ah, you will have a lot to unlearn and learn. At least I have some consistent things between the software and mount (which I'm hoping to still receive this afternoon).

I happened to read this article today about a remote setup at Coona. with an AP mount. You might find it interesting (see #10) re some tracking issues relating to balance. The entire site is worth having a look around at and very good to get an overview of the difficulties of remote telescope control. PS I want that TEC180!

http://www.jadescope.com/Articles/An...9451120_hhV32p

When do you expect your mount?

Peter
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