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HEQ5 Pro Alignment Questions

SnakeyJ

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SnakeyJ

SnakeyJ

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Two hopefully simple questions re HEQ5 alignment...

Firstly - I've just noticed that when I polar align my mount I can not see Polaris through the telescope in the home position even with a 24mm EP. It is present but 2/3rd out on the 9x50 finder. Is this cone error or missaligned polar scope?

Secondly - When doing a three star alignment, I currently use Arcturis for 1st star and Vega as the 3rd star. Until recently I was using Denebola as the second star, but this is now out of site behind the roofline to my northern horizon, as are all the 6 stars that Synscan offers me. Can I get Synscan to offer an expanded list (either Deneb or Altair would be great) without exiting and restarting the alignment? Or should I choose other than Arcturis for my start point?

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Steve Ward

Steve Ward

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Hi Jake.

1. You are aligning the mount not the scope , you won't see Polaris in the EP.

2. The handset should have more than 6 to offer , try scrolling up or down with the bottom left or right buttons til you find a star that's in view.

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SnakeyJ

SnakeyJ

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Steve - thanks for responding on this.

1. You are aligning the mount not the scope , you won't see Polaris in the EP.

I was thinking that the in the home position the axis of the ota should be parallel with the polar axis as seen through the polar scope.

2. The handset should have more than 6 to offer , try scrolling up or down with the bottom left or right buttons til you find a star that's in view.

Definitely only getting a choice of six N/NW stars after setting Arcturis as the 1st alignment point. Next time out I shall try starting with Altair and how this affects choices - I suspect that the Synscan controller firmware limits the choices to give a minimum angular offset for alignment accuracy, but sadly this doesn't take my limited north/northwestern horizon in to consideration.

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Tinker1947

Tinker1947

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I have a polar align option in the latest handset firmware, so i set the scope to the home position, if its dark enough i place polaris in the the telrad inner circle offset as it would be in the polar scope, do a 2 star align, then a polar align, then a single star align, this on my system (NEQ6) works very well....

On the first alignment, first star only i release the clutches and move the scope by hand to align the star, increasing the power of the EP as it centres .......

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SnakeyJ

SnakeyJ

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Thanks Russe and Tinker,

Ok, the ota is at least pointing north ish at approx the right elevation - I'll be content with seeing polaris off centre in the finderscope ;)

I do have the Hitec Astro EQDIR, but unused thus far - I will have a play, but wanted to make sure the mount and ota were as nicely setup and balanced as possible to see how I can get on with unguided subs prior to getting an OAG setup.

I'll check the f/w updates for Synscan - currently using V3.28 EQ

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IanL

IanL

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Firstly - I've just noticed that when I polar align my mount I can not see Polaris through the telescope in the home position even with a 24mm EP. It is present but 2/3rd out on the 9x50 finder. Is this cone error or missaligned polar scope?

It could be one of three things:

- Bad polar alignment :) I'm assuming not as you haven't mentioned any tracking or alignment issues. One thing to check is that the polarscope reticule is centered. rotate the RA axis so that the counterweight bar is horizontal. Now centre polaris on the crosshair in the middle of the reticule. Rotate the RA axis 180 degrees and check that polaris stays on the crosshair as you rotate. If it moves a long way off then you need to adjust the reticule to centre it using the grub screws (lots of guides around on how to do that so google for one).

- Assuming your polar alignment is good it could be that home position not quite right. Polar align and park the scope to the home position. Start with a low power eyepiece and look for Polaris. If you can't see it, then unlock the Dec axis clutch and move the OTA in Dec to see if you can find it. If you can, then you need to aim the scope so that Polaris is slightly off centre to match the view in the polarscope. Increase magnification and repeat if you wish. Use the other fainter stars in the FOV and a star atlas or planetarium to figure out where the NCP is in relation to Polaris and try to centre the OTA on it (not on Polaris itself). Lock the DEC clutch as you have now found the true home position and can proceed to alignment.

- If you can't get the OTA centred on the NCP by rotating the DEC axis only, then you have cone error. You will need to raise one end of the scope to get it properly aligned. You can do this using cone error screws; some dovetail bars have small screw holes in each corner. You put screws through these to push on whichever end of the OTA needs to be raised to get the scope aligned. If I recall the procedure is described in some of the SkyWatcher manuals. If your dovetail bar doesn't have the necessary holes (and you can't add them yourself), then you would use some shims between the tube ring and the dovetail bar to make one ring slighty higher than the other. Cut up pieces of an Aluminium drinks can and drill holes through them to make the shims and stack as many as you need to make the adjustment (it is more laborious though, as you have to remove the OTA and the ring to make and test each adjustment).

The only reason to worry about cone error is if you can't get your alignment stars in the eyepiece to get going after polar alignment. It might be easier to use a low power eyepiece or a properly aligned finder to get the alignment stars in to the field of view. I believe up to date SkyWatcher handsets correct for cone error once you have done a mutli-star alignment (perhaps someone can confirm that point)? Cone Error makes no difference to tracking for visual or imaging purposes, so the only reason it can be a hassle is during that initial alignment.

See my post here for an explanation of why Cone Error does not affect tracking:

http://stargazerslounge.com/topic/181544-guiding-mn190/page__st__20#entry1883415

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astrosathya

astrosathya

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Hi,

With the latest version of the firmware, V3.35, you can switch that auto star select off so that it will display the entire list of stars for you to choose from. This should be good help. This version also has a Polar alignment option (visible after 2 or 3 star alignment) to do an accurate polar alignment without seeing the pole star.

Hope this helps

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SnakeyJ

SnakeyJ

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IanL - thanks for such a detailed response/great post. Some extremely useful information here and in the thread on cone error - I shall work through the guidance to get it as tight as possible. I did do polar scope reticule adjustment on a TV mast a couple of months back, so think this should be in the right ball park, but clouds permitting will fine tune this on Polaris. Polar alignment seems pretty good with Synscan reporting errors in 5-6 arcsecond ranges after a successful three star alignment, it certainly seems to perform okay on goto, though I do get some drift on imaging at higher mags/longer focal lengths.

Astrosathya - Thanks for the info on the new firmware, I have to find the serial cable but will get this upgraded asap ;)

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Russe

Russe

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I always do visual polar alignment as described above (LIKE) with the help of "polarfinder" (to put Polaris at the right spot).

Then I turn on "alignmaster" and visually run through one alignment.

Then put my SPC880 in and repeat the "alignmaster" routine. Takes 5-10 min.

I don't use EQDIR. I put Synscan into direct PC mode and connect it via an RS232 to my laptop and use EQMOD.

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SnakeyJ

SnakeyJ

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Thanks Russe - I shall get my serial cable out and investigate the EQMOD/Alignmaster route and see this performs, Alignmaster looks really useful, but hadn't heard tell of this before your first post.

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astrosathya

astrosathya

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Jake,

The Polar alignment routine in the Synscan handset uses the same method as align master mate, I read the theory of its working and both follow the same procedure. So, unless it is absolutely necessary to have 59 cables hanging around to become a trip hazard :p

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SnakeyJ

SnakeyJ

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Cheers Knobby - the Canadian site worked for me as well tonight and after a fraught couple of hours making up a serial cable and faffing around with the pin outs I finally realised that the DB9 pins were for the male com port, not the reverse on the female DB9 plug. First attempt at upgrading completed successfully according to the firmware loader, but left me with a non booting handset. Fortunately it all worked fine on the second attempt and other than a few grey hairs and chewed nails, I'm good to go again.

Left it too late to go out and adjust for cone error tonight, but some clear weather due over the week so here's hoping.

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astrosathya

astrosathya

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Jake et al,

Please remember that this firmware is a little unique. Unlike Celestron handsets that show the polar alignment always, the Synscan will show it to you IF and ONLY IF you do a 2 or 3 star alignment. First it shows the Polar Alignment error and then you can choose the Polar Align option to make corrections. Typically three iterations and twenty minutes should allegedly get you about 5 arc seconds to the NCP. This is actually very very accurate.

Remember, someone truly said that Good guiding is achieved when you have to guide very little.

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Russe

Russe

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While synscan is a handy bit of kit, I'm so happy I switched to EQMOD and am now controlling my mount with a playstation WIFI controller and instead of searching for objects in the synscan menu, I choose them in Stellarium.

The programmes you need for that are:

ASCOM/EQMOD

Alignmaster

Polarfinder

Stellarium

StellariumScope (plugin programme)

Oculars for Stellarium (plugin as above)

The kit you need is a RS232 to USB connector (unless you have a RS232 serial port on your comp) connecting synscan with your comp.

A wifi game controller.

Probably a USB hub... Careful, they usually require an external power supply!!

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SnakeyJ

SnakeyJ

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Just to close this down - I got the new version of Synscan down and tried it out tonight. First up it offered exactly the same alignment stars, prior to disabling the auto select option 0 but it now works and gave me 5as 7as errors after 3 star align. I checked the polar scope reticule on polaris, though this pretty much dead on NCP through full rotation. I have remounted and balanced the scope to try and minimise any flex in the SW Dovertail and put another Dovetail on top of the scope to stiffen things up further. I still have significant cone error, yet to be adjusted out but things are about as good as I can get without spending any more money. Goto's were spot on, going straight to Saturn @ F25/5000 with the QHY5L-II, off to Spica to use the focus mask, then back to Saturn and finally on to M13.

Tracking looks nice and steady up to F26 on Saturn - though the seeing wasn't good I still got 24000 frames of Saturn wobbling around in a 400x400 ROI. M13 has remained centred in the cameras fov for about an hour now @ F10/2m.

Think I might be ready to try some guiding now in the not too distant!

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Russe

Russe

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I'm confused suddenly - should the home position always be the position when Polaris is in the little circle through the polarfinder? I mean, obviously if the circle is in the right place and the scope is levelled and balance.

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