Polar Alignment with the AM5 - Forums

Lately it's been taking me up to 20 minutes to polar align. Granted, I am going for high precision, under 1 arc-minute on both altitude and azimuth axis. But when I get dialed in really close and I make really small adjustments, I often overshoot and find I have to move either Alt or Az in the opposite direction. Does anybody have any tips as to get my PA down to under 10 minutes? Plate solving isn't the issue, the camera is plate solving. It seems to be the the alt–az adjustments are are simply not fine enough. Maybe it's me.

Thanks,
Jerry

Don‘t Look on the Ranking. Mainly in the last steps be very careful with setting the axes. Be very patient.
Use the slightest movements of your fingers.
And do not use the automatic mode. Refresh manually, that is very important.

I need 20 min and more for a good polar alignment. Never less!! But then I‘m close to the inner circle or within.
Maybe Gary is right, it‘s not worth and waste of time.
Best Thommy

My only advice is when you make an adjustment to the axes do so in tiny increments. You would be amazed how small the movements need to be to set it way off.

When i start getting close, i snug up the axis locks. Not completely tight, but enough that the axis can still move. Then I focus on dec and lock it down. Re-test, and if dec is good I move to RA. Get it good, lock it down and retest.

Then i return to home and do another PA to double check.

also, make sure your mount doesn’t move on the tripod. I fought with alignment one time and found that the locks on the riser had come loose. Boy was that a close call !!!

Hi Jerry,
I have an AM5 and really enjoy using it - it's a great little mount.

I used to try to get a PA of < 1' , but found that it took way too long, and made very little difference at the end of the day because I was imaging guided as opposed to unguided.

Of course a good PA is always better than a bad one, but experiment has taught me that anything < 10' is sufficient, and takes only a few minutes to do - so I can get on with imaging instead of fiddling with adjustments - and my images turn out just as good.

So my advice is … aim for < 10', and celebrate if you're lucky enough to get anything better than that

The more annoying axis is the Alt - there is quite a lot of backlash there. I find that by tightening up the alt clutches, I can feel when the alt gear engages after changing direction. But best to be patient and do lots of small adjustments in a single direction - if you overshoot then you have to reengage in the other direction. Az is a bit easier if you keep the tension on both knobs - release the opposite one just a bit and then press the other against it. I usually leave auto on but wait for a full cycle before doing anything else.

There are two more tricks - which I learned the hard way …

If you are using something like 3PPA in NINA or AsiAir, you need to wait for TWO image cycles before you get a clear reading. The image immediately following your adjustment is going to be streaked because of the small amount of movement in the OTA during your adjustments.

So - watch your images while PA is running and only rely on ones that have no streaks.

The other trick …

Make sure you LET GO of the knobs as soon as you adjust them - even the slightest bit of pressure on the knobs while you are waiting for the next image to load will mess up your alignment.

Sean Mc:
When i start getting close, i snug up the axis locks. Not completely tight, but enough that the axis can still move. Then I focus on dec and lock it down. Re-test, and if dec is good I move to RA. Get it good, lock it down and retest.

I can also attest to loose alt/az locks leading to too much movement. Especially adjusting altitude can rotate the mount around the azimuth axis. When tightened there is no problem for me getting PA down to a fraction of a minute and I have to do it every session due to travelling to a dark site.

Just adding my 2 cents and concurring re the alt/az locks. I snug them up for the final adjustments. I also have a weight in the netting of the tripod to eliminate any chance of the tripod moving/settling during rotation of the mount as it finds targets. I have never gone back and checked alignment after the initial PA but then again I am using a wide angle scope (Redcat51) with guiding so not as urgent as with longer focal length scopes. Before alignment I make sure also the adjustment screws are in the middle of their range so as not to chance hitting the end and having to redo the process of PA. Good luck!

My first two times aligning the AM5 were 20 minutes+ for me as well and I was really getting frustrated. Now I can get it aligned in less than 5 minutes by doing the following:

tighten the east/west locks medium tight.. not cranked down, but not loose - this lets me adjust within about 1 arc minute and then a final tweak by just tightening the East/West knob without loosening the opposite one. Really fine grained small amount of movement against the tension is all it needs. Probably won't even perceive any physical movement, but it definitely shows up on the polar alignment. I never need to loosen the az clutches, they are set it and forget it for subsequent set up nights and the knobs handle adjustments just fine.
tighten the altitude clutches to medium tight as well. it is tight enough if you try to lower and you feel only slack on the adjustment bar and it doesn't move down without releasing the clutches. The goal is to have the clutch at that tightness and then only adjust up (against the tension from the clutches), not down. If I have to go down, the clutches need to be released and it throws so many other things off like even the az. Not 100% sure why, but I think its the movement of releasing the alt clutches that ever so slightly move the az unintentionally as well.

My first two times aligning the AM5 were 20 minutes+ for me as well and I was really getting frustrated. Now I can get it aligned in less than 5 minutes by doing the following:
tighten the east/west locks medium tight.. not cranked down, but not loose - this lets me adjust within about 1 arc minute and then a final tweak by just tightening the East/West knob without loosening the opposite one. Really fine grained small amount of movement against the tension is all it needs. Probably won't even perceive any physical movement, but it definitely shows up on the polar alignment. I never need to loosen the az clutches, they are set it and forget it for subsequent set up nights and the knobs handle adjustments just fine.
tighten the altitude clutches to medium tight as well. it is tight enough if you try to lower and you feel only slack on the adjustment bar and it doesn't move down without releasing the clutches. The goal is to have the clutch at that tightness and then only adjust up (against the tension from the clutches), not down. If I have to go down, the clutches need to be released and it throws so many other things off like even the az. Not 100% sure why, but I think its the movement of releasing the alt clutches that ever so slightly move the az unintentionally as well.

I concur. That's exactly the method I am discovering is best.

Doing the altitude first seems to speed up things assuming your mount is level.

Jerry Gerber:
Lately it's been taking me up to 20 minutes to polar align. Granted, I am going for high precision, under 1 arc-minute on both altitude and azimuth axis. But when I get dialed in really close and I make really small adjustments, I often overshoot and find I have to move either Alt or Az in the opposite direction. Does anybody have any tips as to get my PA down to under 10 minutes? Plate solving isn't the issue, the camera is plate solving. It seems to be the the alt--az adjustments are are simply not fine enough. Maybe it's me.

Thanks,
Jerry

Usually i do PA in 3-4 minutes, precision under 00' 00'' 20''.
For first i adjust ONLY alt, then AZ after closing alt screws. And then restart. NEVER do alt and az at the same time.

There are some great tips in this thread. Thank you all for your input

Michele Campini:
Jerry Gerber:
Lately it's been taking me up to 20 minutes to polar align. Granted, I am going for high precision, under 1 arc-minute on both altitude and azimuth axis. But when I get dialed in really close and I make really small adjustments, I often overshoot and find I have to move either Alt or Az in the opposite direction. Does anybody have any tips as to get my PA down to under 10 minutes? Plate solving isn't the issue, the camera is plate solving. It seems to be the the alt--az adjustments are are simply not fine enough. Maybe it's me.

Thanks,
Jerry

Usually i do PA in 3-4 minutes, precision under 00' 00'' 20''.
For first i adjust ONLY alt, then AZ after closing alt screws. And then restart. NEVER do alt and az at the same time.

Hi Michele,

What do you mean by "restart"?

Jerry

Following on from Wayne's comments about weights ...

I bought the TC40 carbon-fibre tripod with my AM5, but found it was a bit wobbly and definitely not stable enough. The weight netting that came with the tripod helped a bit, but didn't stop the tripod legs from flexing, particularly the thinner and less rigid bottom sections. I found that the more weight I put in the net, the more the lower parts of the legs flexed - and the centre of gravity was too high.

I tested the AM5 using a Askar 130PHQ, which weighs about 15kg including all the camera gear. The whole lot toppled over when I slewed to zenith - simply because the base area of the tripod is too small - it was a miracle I caught it in time before everything ended up in the flowerbed.

So, I designed a 3-point tripod spreader to stabilise the top part of the tripod, as well as foldable arms that attach to the bottom of each leg where I can add a kettle weight. These all fold down flat so the tripod can be folded down as usual, with no removal or disassembly.

This made a MASSIVE difference.

With a large telescopes like the Askar, adding a kettle weight to each leg makes the tripod as stable as my much larger iOptron Tri-pier.
When I'm done, I just fold down the tripod as usual and pop the kettle weights in a carry bag - I can even use them in the gym

I designed these parts for my own setup, but so many fellow astronomers wanted them (and other parts), that I made them available to others - you can see them online here - scroll down a bit and you can see the tripod parts - just click the image to play a video.

Gary JONES:
Following on from Wayne's comments about weights ...

I bought the TC40 carbon-fibre tripod with my AM5, but found it was a bit wobbly and definitely not stable enough. The weight netting that came with the tripod helped a bit, but didn't stop the tripod legs from flexing, particularly the thinner and less rigid bottom sections. I found that the more weight I put in the net, the more the lower parts of the legs flexed - and the centre of gravity was too high.

I tested the AM5 using a Askar 130PHQ, which weighs about 15kg including all the camera gear. The whole lot toppled over when I slewed to zenith - simply because the base area of the tripod is too small - it was a miracle I caught it in time before everything ended up in the flowerbed.

So, I designed a 3-point tripod spreader to stabilise the top part of the tripod, as well as foldable arms that attach to the bottom of each leg where I can add a kettle weight. These all fold down flat so the tripod can be folded down as usual, with no removal or disassembly.

This made a MASSIVE difference.

With a large telescopes like the Askar, adding a kettle weight to each leg makes the tripod as stable as my much larger iOptron Tri-pier.
When I'm done, I just fold down the tripod as usual and pop the kettle weights in a carry bag - I can even use them in the gym

I designed these parts for my own setup, but so many fellow astronomers wanted them (and other parts), that I made them available to others - you can see them online here - scroll down a bit and you can see the tripod parts - just click the image to play a video.

I use the AM5 and the Askar 130PHQ with the Ioptron Tri-Pier and ZWO PE200 pier. The TC-40 tripod is fine for the Esprit 100 and the Edge HD8 but for the Askar I found the heavier tri-pier (and the ZWO PE200 pier) a necessity to keep the scope from hitting the tripod legs when imaging near zenith.

I found that the rubber feet on the zwo tripod caused wobble. Switched thrm out for the included spikes.

To be fair to the tripod, it’s pretty good for it’s purpose of being a packable featherweight.

Jerry Gerber:
I use the AM5 and the Askar 130PHQ with the Ioptron Tri-Pier and ZWO PE200 pier. The TC-40 tripod is fine for the Esprit 100 and the Edge HD8 but for the Askar I found the heavier tri-pier (and the ZWO PE200 pier) a necessity to keep the scope from hitting the tripod legs when imaging near zenith.

Hi Jerry,
Yes, you are absolutely right about the height issue.

I generally use the AM5 with an Askar 180PHQ, but found that the PE200 provides just enough height for the 130PHQ, provided I use the kettle weights to stop the tripod getting unstable at extremes such as imaging near zenith.

Sean Mc:
I found that the rubber feet on the zwo tripod caused wobble. Switched thrm out for the included spikes.

To be fair to the tripod, it’s pretty good for it’s purpose of being a packable featherweight.

Hi Sean,
Yes, I had the same issue with the rubber feet.

I use the rubber feet when on grass, and the spikes on hard surfaces. I drilled little depressions into the pavers on our back deck, which the spikes sit into - makes PA much easier every time I set up.

Gary JONES:
Sean Mc:
I found that the rubber feet on the zwo tripod caused wobble. Switched thrm out for the included spikes.

To be fair to the tripod, it’s pretty good for it’s purpose of being a packable featherweight.

Hi Sean,
Yes, I fhad the same issue with the rubber feet.

I use the rubber feet when on grass, and the spikes on hard surfaces. I drilled little depressions into the pavers on our back deck, which the spikes sit into - makes PA much easier every time I set up.

Yup! That’s what I did as well

Sean Mc:
Gary JONES:
Sean Mc:
I found that the rubber feet on the zwo tripod caused wobble. Switched thrm out for the included spikes.

To be fair to the tripod, it’s pretty good for it’s purpose of being a packable featherweight.

Hi Sean,
Yes, I fhad the same issue with the rubber feet.

I use the rubber feet when on grass, and the spikes on hard surfaces. I drilled little depressions into the pavers on our back deck, which the spikes sit into - makes PA much easier every time I set up.

Yup! That’s what I did as well

I’ve tested out these feet for the AM5 tripod and they work quite well in hard surfaces:
https://www.amazon.com/dp/B0BPL5YNXR?ref_=pe_2409890_445922140

Its not you Jerry, super accurate adjustments are very difficult.

Easiest to get a smiley face and be done with it in my experience.

Getting both axes below an arc minute is far too time consuming.

I have not had a problem with just getting it to the smiley face and leaving it there (perhaps a little bit towards the center) even with a 1400mm focal length - good guiding and not excessively long subexposures help. I am guessing someone will have some maths (or data) for this - how precise the PA needs to be given FOV, exposure length and distance of target from the pole.

Maybe I'm missing something, but using sharpcap it takes me MAYBE 5 minutes to polar align. It's very, very easy with the am5's high quality machining and tolerances. But maybe because I'm used to the eq6r mount, which is not very forgiving.