What could it be?

[xelasnave]

So in keeping with me ramping up my wide field imaging I put the camera on the HEQ 5 together with a guide scope and camera expecting to run off some long subs at low iso and take flats etc...a proper run...everything was well planned and much preparation went into making sure everything was in order.

So I connected everything in PHD guiding successfully and it would select a guide star as one would expect but it gave me a message that it could not correct enough in RA etc...OK I switch off PHD and take a good look at the stars and to my horror they are rushing across the screen as if tracking was not on..check that..it's on..fiddle with the counter weights and notice a very small improvement but still alarming..so I do a factory reset, then check everything even try it on Solar and Luna tracking , try everything in auto guide speed..then I put a huge counter weight on that would be ten times or more overkill..small improvement but it is ridiculous...so I thought sleep on the problem and went to the 115mm on the eq6 and started getting some subs...but the night was gone but got 10 mins in RBG and HA to play with but I may add to them tonight if I sort out the eq5 and can forget that issue.

Now it should not be power as the brick is new and I have had it moving the 80mm and cameras ..all I can think is the mount needs more weight than just a camera and guide scope..that's clutching at straws I suspect..exercised everything dragged the clutch and made sure it was biting...anyways I have been working on everything around the observatory today and will put on the 80 mm and balance it and see if that causes the mount to come good.

I don't think I need advice but more of trying to think more by writing it down but if you have experienced similar and can point to what I am missing please point me in the right direction because as at this point it has me beat.

But the wonderful thing today... I added a flooring infill around the pier mat which not only makes it look nice but now eliminates a tripping opportunity that has nearly dropped me on a couple of close calls.

It has to be the mount needs more weight to function I hope.

Alex

[JA]

Hi Alex,

If you have checked:
1. the RA clutch is properly engaged,
2. that there is sufficient power,
3. that the mount is set ON to track at the sidereal rate and
4. the mount is balanced
then the problem is likely to be electromechanical. Perhaps a defective RA motor, poor connection, defective drive electronics or a drive gear/pulley slipping on a drive shaft.

The HEQ5 has an RA setting circle with a small clamp screw. Zero the setting circle against the marker to measure how much the mount moves in 1 hour when tracking is set to ON at the sidereal rate. It should move 1 hour of time on the setting circle (clock), the equivalent of 15 degrees. Or perhaps test it over a few hours for greater accuracy. It wouldn't hurt to also confirm the battery voltage and look for any loose power connections



Best
JA

[glend (Glen)]

I agree it sounds like the RA clutch might be a good place to start. You do need a little bit of weight on the bar I suspect. I have used a small ankle weight (on of those strap on exercise bean bag things).

[xelasnave]

Thanks JA.
1. Checked and re checked not the issue.
2. The power should be ok but later I will plug the brick into the genny...the 240 vlt comes from a 12 volt bank via an inverter and last night the genny was charging the batteries so they had plenty of power...
3.Tracking set on sidereal.

I have now placed the 80 mm on it and will try that out plus conect direct to the genny which will narrow down things. I am looking for another power supply box to determinecif it is the brick but it slews ok at 9 on both axis at once no complaints...and there is no blinking light which I think manifests if the mount needs more power.... I am obviously hoping it has fixed itself...if not no matter I will just move on to something else for the moment.

Thanks for your help.

Alex

[xelasnave]

Well I think the problem has solved itself as it at least passed the hour run test...I will have something to eat and by then it will be dark enough to do a test imaging run but so far so good.
Thanks JA the idea to do a hour test run has enabled me to eat as I know that if not somewhat resolved I would not have eaten ... but I can't wait to see stars on screen.

Alex

[Startrek (Martin)]

Alex,
Are you sure your polar alignment is good ?
Just a thought
PHD2 can correct up to 5 or 6 arc min quite well but over that , field rotation , excursions etc….
Maybe run the Guide Assistant in PHD2 ( takes 10 mins and could pin point your issue )
Cheers
Martin

[xelasnave]

Thanks Martin...polar is perfect.

Anyways the problem has gone now and all I can think is the lack of load caused the issue...
At the moment it is running carrying the 80mm and zwo 2600 OSC...30 seconds high gain trip as it was cloudy earlier..in fact I only got to track for 30 seconds and a following minute to see if there was any trailing ( none) before the clouds rolled in...I played around for some time and it cleared and I did further tests and all good..I did not fit the auto guide to this unit ...anyways I have both the eq5 and the eq6 running but I am not serious it is just too wet.

Very happy but would like to understand why.

Alex

[Startrek (Martin)]

Ive had my fair share of unexplained gremlins using PHD2
Best not worry about it and move forward
As long as you tick all the boxes and it’s running ok then the rest is up to the atmospheric gods

Martin
PS : I’m imaging the Lobster at the moment and our suburb had a brown out for 2 seconds at 8.15pm. The mount just froze and I had to manually bring it back to home position, close all apps and reboot restart from scratch. Waisted 30 mins , back imaging again
Beautiful night in Sydney, no moon , no dew , light wind and great guiding so far
Fingers crossed hope to go through to the early hours

Cheers
Martin

[xelasnave]

Originally Posted by glend

I agree it sounds like the RA clutch might be a good place to start. You do need a little bit of weight on the bar I suspect. I have used a small ankle weight (on of those strap on exercise bean bag things).

I could not buy any lead flashing in Tabulam and had a variety of tools taped on...but I do think it needed more weight overall..anyways its going thank goodness.

alex

[xelasnave]

Originally Posted by Startrek

Ive had my fair share of unexplained gremlins using PHD2
Best not worry about it and move forward
As long as you tick all the boxes and it’s running ok then the rest is up to the atmospheric gods

Martin
PS : I’m imaging the Lobster at the moment and our suburb had a brown out for 2 seconds at 8.15pm. The mount just froze and I had to manually bring it back to home position, close all apps and reboot restart from scratch. Waisted 30 mins , back imaging again
Beautiful night in Sydney, no moon , no dew , light wind and great guiding so far
Fingers crossed hope to go through to the early hours

Cheers
Martin

One should made a book containing all the things that go wrong..brown out...mmm you best get one of those power boxes they have for computers.

alex

[Crater101 (Warren)]

As someone who is just dipping their toe into the deep waters of astrophotography (and I wouldn't know one end of PHD from the other) my first thought was your power supply.
I don't know what you're using, but was there a power surge / fluctuation? If you're using a battery system, how old is it? I know from my own use of battery systems over the years that some systems can start to exhibit some odd behaviour when they begin to near the end of their service life.
Anyway, it's just a thought. Pleased that it's all going OK for you anyway.

[xelasnave]

Originally Posted by Crater101

As someone who is just dipping their toe into the deep waters of astrophotography (and I wouldn't know one end of PHD from the other) my first thought was your power supply.
I don't know what you're using, but was there a power surge / fluctuation? If you're using a battery system, how old is it? I know from my own use of battery systems over the years that some systems can start to exhibit some odd behaviour when they begin to near the end of their service life.
Anyway, it's just a thought. Pleased that it's all going OK for you anyway.

Thanks you Warren for thinking about the matter.

I have been caught a few times with power issues with mounts and so the test that I ran very early in my sesrch for a cause of the situation was check the power and so I decided to run both dec and ra motors at full tilt by selecting 9 in the speed choice..they ran with no problem ..also the red light was not flashing which is usually associated with low power situations.

I was confident that power was not a problem but in these areas I agree that is so often the problem.

Thanks again.

Alex

[Hodur (David)]

Alex, I once had a similar issue…. Checked the sidereal tracking it was switched on. After much fuss and bother I placed my ear onto the mount, it wasn’t tracking. Perform this simple physical check and you’ll have definitive proof as to the functioning of sidereal tracking.

[xelasnave]

Originally Posted by Hodur

Alex, I once had a similar issue…. Checked the sidereal tracking it was switched on. After much fuss and bother I placed my ear onto the mount, it wasn’t tracking. Perform this simple physical check and you’ll have definitive proof as to the functioning of sidereal tracking.

Hi David thank you for your input.

I have had many occassions where mounts have caused me to look for the axe but the first thing I do/did is have a listen and in this case you could hear the sweet little thing, so it told me it should be working but certainly noise and stars told me "It must be power" but as I said the power was ok.

Now the only thing that changed from very poor tracking to very good tracking is that I changed the payload.

The problem existed when I only had my Nikon camera and a small 50 mm lens together with a small guide scope and it's little camera..the problem disappeared when I replaced those units with my 80mm triplet with a two 2600 OSC....why? I don't know why that made the difference but that was the only thing...after the change I ran the mount for an hour tracking in RA and at the end of the hour is was close to where it should have ended up but perhaps a degree short of where I expected...now that suggests that perhaps by running the thing for a long time it fixed something ,...maybe? Like why the missing degree..was it running poor and then whatever cleared? The missing degree suggest such.

I simply don't know what the answer really is..or was..and my thoughts as to extra weight or a long run fixing whatever are too nebulous to make me feel I have a legitimate answer...now if the next time I use it the issue presents again it will get the axe for sure or maybe a pull down and clean inspection etc...

Maybe we can make a list of what to do...

Check hand box that tracking selected,
Can you hear motor etc,
Is the red light flashing
Will it perform in both RA and Dec at highest speed
Is balance correct
Any cables snagging
Clutch engaged

Please feel free to add something if I have missed something which I suspect I may have.

Thanks again..I must say when I bent over and heard that sound I actually felt relieved because given the tracking showed as on via the hand box I had convinced myself the motor was gone...

But these days I just don't despair as I have had so many issues over the years that keep you awake all night with worry and confusion all of which resolve in a matter of days I have learnt to be patient as thing always come good and there is nothing to be gained from working yourself up or busting stuff up with the axe...but I make a point of not owning an axe....

Alex