Problem solving...

[msinclairinork]

Right..that's it! The gloves are coming off! No more Mr nice guy!

I'm going to tackle and solve this Declination guiding issue if it's the last thing I ever do! (Dec calibrates then falls of the graph quickly)

I've made a list and if this doesn't fix it......................I QUIT!!

1. Check Balance again

2. Use SGE in Daytime

2. Check with Laptop conected (as oppose to PC)

3. Upgrade to Ascom V6, PHD V1.13.0b

4. Check PA again

5. Change exposure to 2s once calibrated

6. Up MAX DEC Duaration to 1500

7. try dec on north/south rather than auto

8. Manual guide to test.

9. Use AA5 trial instead of PHD

10.Change DSI USB Cable

11.Re-plug RJ45 connection on EQDIR

12.Aim for ~10 steps calibration rather than 16

13.Strip scope and mount of pier and put back on tripod

14.Buy HItech astro USB ST4 & Try pulse guiding

15.Strip and re grease mount

Any thing else worth adding?

Wish me luck!

Michael

[Tim]

It'll just be something simple.

Is your mount reasonably well polar aligned?

Can PHD move your mount with both motors?

[msinclairinork]

I hope it is Tim, but I've failed to find the problem on a few long nights spent on it.

I know it's all a learning process and I'll probably be better off (knowledge wise) when/if I figure it out..But it sure is disheartening as I watch some of my targets I had in mind to image get lower as the weeks pass! The highs and lows of astro imaging eh?

I've polar aligned with EQMOD twice to be safe so it should be OK. The RA is guiding fine. I've tried manual guiding and it did look like it was working in both motors.

The really strange thing was that I had just got my setup working so well - where I could just turn it all on and be imaging a target in 5mins! That's when I think I made the crucial mistake...I said to the wife - "ahh I really like my setup now, look how easy it is!" then the next time I turned it on...ERROR!!! I don't know whether to laugh or cry!

This was a post last month, which has the screen grabs etc. http://stargazerslounge.com/discussions-software/166128-phd-need-help.html

Thanks,

Michael

[msinclairinork]

Is there a method to checking for physical motor problems i.e backlash? Should I be thinking of opening up the mount and looking for anything? The mount is not even a year old yet though?

Thanks,

Michael

[ollypenrice]

Make sure all the guide connections are working. I had one on the back of the guide camera which was distorted and I corrected it with a pin.

Olly

[msinclairinork]

Will do Olly,

Thanks,

Michael

[Komet]

I would try AA5 first before anything else. If it doesn't work in that then you do have a problem. PHD just didn't work for me and I know others that have had similar problems.

Just try AA

[msinclairinork]

I certainly will Mick. I know you had this exact problem with PHD and it does give me some hope that it is just a software issue.

I did try AA5 trial one night but failed to get it guiding - I managed to install the camera (DSI) but couldn't figure out how to get it guiding.

I don't suppose you wouldn't mind giving me instructions?

Thanks,

Michael

[RogerTheDodger]

I haven't had a chance to try it myself yet due to the weather, but have a look at drift alignment with EQalign http://eqalign.net/e_downloads.htm (not everything is translated yet, but working through the PDF is not too hard in simulation mode and can be done in the day).

EQalign can also do guiding, so may be useful to eliminate PHD which is what perked my interest initially - it also has the advantage of being free current version is 2.3.9

[msinclairinork]

I'll give it a go! Thanks.

I'm fairly certain it can't be my PA tho' as it's been fine for months, and then one night it doesn't work?

Michael

[RogerTheDodger]

It's worth a check, especially as it is free and easy to use and the guiding part is worth a try to eliminate PHD.

[msinclairinork]

Absolutely Roger. I'm willing to try anything at the moment!

Michael

[RogerTheDodger]

Been thinking about this, from when it worked to when it failed, were you looking at a very different RA/DEC part of the sky? If so I'd be looking at PHD settings.

Other things you can update are EQmod to a later version, and I have PHD versions 1.3.1 and 1.3.2 from Craig that he sent me as bugfixes for an LX cam problem I had

[kookoo_gr]

first i would check the easy parts

1. Balance

2. PA and drift align

3. Cable snags

4. Different usb cables/hub

5. Use laptop

6. use last stable software version for guiding. I had problems with the latest eqmod version along with phd and i use eqmod 1.20k and phd 1.12 and ascom 6

7. use ascom pulse guiding (via usb port). it is better than st4 guiding.

also you should check the mount for the following

i found that the silver allen screws of the ra/dec wormgear get lose after some time and usage. this can lead from bad guiding to a serious accident with your equipment. if the screws are loose then you need to tighten them and check the gears' mesh (see astrobaby's site) Also the screws that hold the dec coordinates/counterweight bar can also get loose. A final note for servicing the mount. There is the possibility that the dec gear (large brass gear) finds resistance at the walls of the the dec axis. You need to use fine sand paper to remove this problem but you can make this step only when you service the mount.

[msinclairinork]

I appreciate that advise! I'll give it all a go.

Thanks,

Michael

[msinclairinork]

Been thinking about this, from when it worked to when it failed, were you looking at a very different RA/DEC part of the sky? If so I'd be looking at PHD settings.

Other things you can update are EQmod to a later version, and I have PHD versions 1.3.1 and 1.3.2 from Craig that he sent me as bugfixes for an LX cam problem I had

I actually was trying to get back on to a target that I was imaging a previous night - so roughly the same area of the sky at that time. I have also tried different areas and the only difference is that the Dec falls off the graph to either to the North or the South depending on what side of the pier I'm on?

Thanks,

Michael

[jgs001]

I do recall someone else having a similar issue... If I remember correctly, the DEC setting in PHD had been changed... In PHD, if you go into the brain, can you post a screen shot

[msinclairinork]

Here you go John...

[kookoo_gr]

i suggest to lower the dec duration from 150 to 100.

Also i forgot to mention that the process with the fine sandpaper is done to improve the balancing procedure of the telescope so it is not necessary to do it

[msinclairinork]

Reducing the dec duration? I was under the impression that increasing it to even 1500 could improve things if like in my case the Dec is having a hard time keeping up?

Thanks.

Michael

[pete_l]

Any thing else worth adding?

Wish me luck!

Michael

The first thing I'd check is that the location (lat/long) is what you expect it to be.

Then check that the time is correct - GMT/BST issue?

After that, check if any updates have "magically" appeared on your laptop¹ (or disappeared, equally magically)

Make sure nothing else is running. Disable all virus checkers, scanners etc.

Unplug all the connectors, then reinstall the cables. Possible "buzz" them with a continuity tester to make sure no joints have broken inside the cable.

Then try reinstalling the software you already use (I wouldn't try updating to new versions just yet - that only adds more variables and uncertainty)

If that lot fails, try stamp collecting instead

[1] if the laptop is the machine you usually use to run all this stuff.

[msinclairinork]

Thanks Pete I'll give all that a go too.

Stamp collecting you say; certainly sounds appealing right now!

Michael

[rfdesigner]

I had this problem on my homebrew mount on my last imaging session.

Turned out to be a slipping clutch on the DEC axis.

Keeping a high "max DEC" makes sense, I went down that exact route. Otherwise it LOOKs like you are doing everything right.. and you must have been to get your previous images.

Other things worth trying (in the dry and daylight): prove you can move your dec via the guide port. The "st-4"-RJ45 connector has 5 wires connected, NSEW and a common (which I think is positive). By shorting the N to the common the mount should move to the North, ditto for east west and south. I would try getting hold of an RJ45 connector with wires (old autoguide cable, which you cut up) and then shorting different wires together. You will be wanting to listen for the motor moving or, if your mount does it,.. reports the guide port instructions to the hand set.

Note: You cannot damage an normal autoguide port by shorting wires together incorrectly.

You are having trouble because you have several layers of signalling getting from the camera to the movement.. one of those has failed, so you need to "divide and conquer". That is test the system at a half way point, that way you can tell if the problem is before or after that point, then divide that half of the system and so on until you find the problem. The solution will probably present itself.

Derek

Using my homebrew autoguide feature, built to the ST-4 "standard".

[martin_h]

I suffer from a huge amount of Dec backlash on my NEQ6, and if left to its own devices PHD will either take an age to clear it, or not clear it at all. So now I centre up my target and then move the mount North a touch, then bring it back South, the South movement (using the move buttons on EQmod) takes a few goes to actualy move the mount, thus removeing the backlash. Then I calibrate PHD, the "remove Dec backlash" bit only takes a second or so that way.

Worth a try.......

Depending on the "unbalance" of your setup you may need to move South, then North depending on where the backlash is.

I might get round to setting the worm on mine one day, but this works for me - for now!

[Komet]

I certainly will Mick. I know you had this exact problem with PHD and it does give me some hope that it is just a software issue.

I did try AA5 trial one night but failed to get it guiding - I managed to install the camera (DSI) but couldn't figure out how to get it guiding.

I don't suppose you wouldn't mind giving me instructions?

Guiding in AA is a breeze.

I have found it best to use two separate instances of AA - one for capture and one for guiding.

1 ..... start an instance of AA

2 ..... Open the CCD control. Select your guide camera, click setup and connect to the camera.

3 ..... you can now click on the Telescope tab to connect to your mount. Once connected, leave it open and select the Guide tab

4 ..... on the CCD panel select the Focus/Guide tab

5 ..... select the binning you require (I use 2x2) and an exposure length. Try 2 seconds for starters. Make the exposure length next to the START button the same length.

6 ..... Click the START button to take an exposure. Choose a star in from the exposure and draw a rectangle round it.

7 ..... Click the large GUIDE button. A small panel will open showing the guide star you have chosen. Do nothing to it.

8 ..... in the Telescope Guide tab click on Automatic Calibration - let it do its stuff, it doesn't take long.

9 ..... Once calibration has finished go to the guide window that shows your guide star and click on the Mark Guide Star button. A cross will appear on your guide star - you are now guiding.

10 .... If you are using EQMod you can fine tune the guiding by adjusting the Pulse Guide Width monitor. This can be done on the fly. You can also adjust the Telescope speed in the Telescope Guide tab. The EQMod way is much better.

11 .... If your DEC guiding just shoots away from the guide star then click the INV box in the Telescope Guide tab.

Sounds complicated but it isn't. I love AA guiding.