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Guiding conversion project for 200p and EQ5

Quatermass

By Quatermass
in DIY Astronomer

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badgerchap
badgerchap

Well I've been coming back to this thread ever since it was started and am finally about to take the EQ5 guiding plunge! Have ordered a smaller newt though - a TS 6", to cut down the weight, which I a

Quatermass
Quatermass

There are no stupid questions when you want to learn more and asking questions is how we all learn from each other. Sharing it with others on this forum is a great way to learn so never feel like your

Quatermass
Quatermass

Its hard to answer your question as I never used the synscan unit on my eq5 and I thought with a synscan your drive motors were able to handle an auto guider as they were a higher ratio then those off

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Quatermass

Quatermass

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Mmm intresting.. the DEC seems to be going all over the place but the RA keeps along the middle line at a nice steady pace. SO far 3 4 and 5 minute exposures all have a little bit of movement in them but I am incouraged to be getting some results even if they are not spot on. If I wasnt so cold out here I might have made a better attempt at polar alignment but my gut feeling is this will work with a bit of tweaking. Might also help if I new what I was doing and how phd graph is calibrated and adjusted.

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austen4

austen4

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hey all,

I have not posted for a bit but I would like to say that I bought the guide port mod and that was a doddle. I also bought a Logitech pro 9000 webcam and took the lens off it. I kept all the original case etc. on and the silver circle round where the lens would have sat but on the outside of the case is just the right size to thread it onto the finder ring on a skywatcher 9x50 finder scope. All you have to do is unscrew the eye-piece for it and just push and rotate the webcam until it becomes tight. TBH it is not the best attachment but I have tried it and it works. Focussing is easy and no mods are needed. Here are some pictures of the webcam and finderscope. I also found that this is quite useful and taking off the webcam and put on the eyepiece for it is simple so you can switch between to two for quickly finding your object and then just centre on the camera. As you can see from the picture, the webcam has no lens and the you can see the sensor. I do have a GPUSB on the way and will update once I have tested with it.

However, I do not think this is extremely reliable and there are better ways. This will do me for a bit until I do another mod to attach the webcam.

Hope this helps

post-29680-133877730188_thumb.jpg

post-29680-133877730191_thumb.jpg

Edited by austen4
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stan26

stan26

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Hey QM, congrats on the guiding! Its finally all starting to happen.

It looks like you need to tweak the DEC. Don't worry i was getting worse results than that when I started. Looking at your graph suggests to me that the DEC is drifting of course and PHD is reacting either to slow or taking to long to take up the backlash to compensate. Once it has caught up the star is rapidly brought back to center, hense the DEC line gradually moves off centre then rapidly makes its way back to the center line. It also looks like its over correcting (over shooting) a bit. This to me is a typical sign of mechanical backlash. You may need to tweak them DEC adjustment screws some more.

Are you guiding in "auto" mode..? is so you should try one direction only in DEC mode. Find out which way the star is drifting (i.e north/south) then set the DEC to only guide in that direction, and make sure if there is any backlash that it is taken up before you start guiding for example if the start drifted north then you would make sure that your last slew movement to center the guide star would be northwards so the slack is already taken up.

Post up a screen shot of you settings and Il have a look. I'm no expert but I think I have a reasonably good understanding of PHD.

Regards

Stan. (p.s off to bed so may not reply till tomoz)

:)

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Quatermass

Quatermass

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cheers for the link bamus.

Well goodness me it was cold out there tonight think Id rather be testing out my guiding rig in the summer time for sure. First tests indicate that some tweaking is needed as exspected but quite reasonable results so far. Will go through my images tommorrow and post results. Now defrosting my feet and hands with a hot water bottle.

Roll on the summer brrrrrr :)

Sent from my GT-S5670 using Tapatalk

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malc-c

malc-c

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QM have you seen this canon battery power supply?

Astronomiser - Automated Astronomy and AstroImaging Solutions

It's a must have in my opinion :) I only have one battery and like you say.. Doesn't last long in the freezing cold! Roll on payday :icon_eek:

Or just buy a cheap replacement battery, remove the cells and then wire the connectors to an 7808 1A regulator with a couple of smoothing caps on the in and outputs.

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Quatermass

Quatermass

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Thanks for the tip there Malcom everyone..

Ok results from last night.

This first one is a full 4 minute exposure at an ISO of 800, even though it was not pin perfect it was certainly something I could not get with my old set up. The next shot is a full 5 minutes exposure at ISO of 800 again not pin perfect but a major improvement on my old set up, trying to get a 5 minute shot before was impossible.

guiding%2520first%2520attempt%2520images%2520013.jpg

It was bitterly cold last night and my polar alignment was not spot on and I need to take some more slack out of the dec gears it seems but I am pretty pleased with the first results having waited so long to try it all out. Once I get some longer cables I will be able to do all this from indoors rather then doing an impersonation of Scott of the Antarctic in my fisherman's bivvy outside.

Still have to understand PHD setting and trying Stans guiding with auto switched off and just north selected seemed to improve things. Its just a matter of fine tuning it all now but off to a good start.:)

guiding%2520first%2520attempt%2520images%2520033.jpg

Also as a bonus I tryed out the webcam on its own and got this shot of Jupiter and Mars, Mars was a first for me so quite pleased with that one.

jupiter%2520and%2520mars.jpg

Edited by Quatermass
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malc-c

malc-c

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Good results considering the resolution of the steppers and the equipment you are using. With better polar alignment and a tweak to the backlash on the DEC I can't see why 5 min subs with pin point stars would not be in possible. Not sure what that bloom is on the right of the 1st image, but it would seem 5 min is the max before fogging etc is more of a problem than tracking.

When you get PHD guiding better, PA spot on and the DEC balance / slack dialed out, try a 20 min test guide... then you know you've nailed it when that results in pin-point stars.

All in all - well done and a very interesting thread :)

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Quatermass

Quatermass

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Cheers Malcolm

The second image was ghosting due to the moon coming up closer to this area. I also messed up several first attempts as the dec motor was catching on the ra motor casing had to turn the dec axis round so the motor was on the otherside. Like most new setups this will take some getting used to in order to understand fully but it has changed my mind about using a laptop. Once I have longer cables so I can come inside the laptop offers a lot of extra control and its will certainly be warmer. I have learned a great deal doing this conversion and glad that I can now do longer exsposures and I also have a webcam for imaging the planets as well. :)

Sent from my GT-S5670 using Tapatalk

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Quatermass

Quatermass

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Just fitted the dual axis motors and in rolled the clouds after a day of blue skies.. Typical! Was going to put the scope out to cool but think it might be a waste of time now..

How annoying curse those clouds. Im hoping it will clear up this evening weather forecast says it will be fair for star gazing so might get lucky. Hope it clears up for you and you get a chance to try your motors out.

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Quatermass

Quatermass

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Well back outside for another session this evening. Its not ideal but I have been able to smooth out the guiding by adjusting a few settings and although the fog is giving me duff pictures the tracking on them is looking pretty good for full 5 minute subs. The graph is nice and smooth now with both dec and ra chugging along nicely. Im new to phd but I guess when its showing this kind of graph its a good thing.

g1.JPG

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malc-c

malc-c

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Trace is looking good.

To give you some idea, here's mine. This is using the ST80 /QHY5 so the settings will be different, but the idea is to try and get the two lines as smooth and flat as possible, so, although both of our traces could do with some refinement, I'm taking 420 second exposures at 800 ISO of M82 at the moment and the stars are pin point sharp, so I'm guessing yours should be too.

post-23388-133877730523_thumb.jpg

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Quatermass

Quatermass

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It was but i took it all apart and cleaned and greased it all so its much better. My problem last night was my settings in phd now im getting the hang of it its guiding well :) worth giving it a clean and tighten.

Sent from my GT-S5670 using Tapatalk

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