AstroEQ for EQ mounts

[Quatermass]

I don't find that an issue really as I can do a quick manual polar alignment and then put the scope on a star near my target then press sync and slew from there no need to wait ages to slew really just move closer to your main target sync on star close by and then move to your target. I did that to find the wall in the north american nebula and it worked great. ;-)

cloud cloud go away come again another day

[chrisshillito]

The correct procedure for usind EQMOD is to power cycle ith the mount at the home position and then issue a goto to your first alignment point. For the first point you can then slacken the clutches and position your mount manually on the alignment star before synching. However all subsequent alignment points must be moved to under slew/goto control.

If you try to shortcut this and just manually position on a star and sync without starting from home and issuing a goto then there is a danger EQMOD will reject the sync offset as being 'too large' .

Chris.

[Quatermass]

Thank you Chris,

I am completely new to all this and dyslexic as well so its quite a steep learning curve for me.

So, I can do a manual polar alignment with my EQ5 mount and then set this as my parked position after which I need to then issue a "go to" command to my alignment point?

I only just learned about alignment points the other day watching one of your videos so am still a bit confused.

To set an alignment point I just manually polar aligned my scope the other night ( I had not sussed out how to set a parking position but have now) so I just moved it to a star and hit sync in CDC and noticed this set a one point alignment for me.

I then selected another star and issued a slew to target command in CDC from that alignment point which seemed to work and get me on my target.

Once I have polar aligned the telescope( I like to do that manually but know I can use EQmod to help with this if needed) and set that as my home position, can I unlock RA and DEC and move manually to a star to centre it in the eye piece and sync to it to create an alignment point, OR- do I have to issue a "go to" command to that star and then hit sync to set it as an alignment point?

I take it I can then select in cdc another target and issue a slew command in cdc to "go to" it from that star selected as my first alignment point.

So much to get to grips with here..

Also wanted to create a pec file with my webcam to use it to correct any pec errors in my gears but that's another learning curve along with pulse guiding and everything else. However I am loving all these features it has to offer.

Finding your videos very helpful because being dyslexic I learn from visual input much quicker.

[Quatermass]

Also a heads up from Tom about the stepper motors. If they are getting to hot you will need to take the screws of the back of you AstroEQ and lift the front cover off. You then will need to turn to tiny screws to adjust the current going to the stepper motors. Here is Toms feedback on this to me for your reference...

Problem stepper motors getting too hot.

They will get warm, but they shouldn't be too hot to touch.

If they are it means they are getting too much current and the limit needs to be set. To do this however you will have to open up the AstroEQ box.

There are two screws on the bottom of the box. Unscrew these and the top should come off.

You will see two purple circuit board (can't miss them) next to the motor outputs. On them there is a potentiometer (a metal cross cut screw head). Here is a picture - the potentiometers are in the top left of this picture if you are unsure: http://tinyurl.com/ojguzol

Turn the pot. on each driver board Anti-Clockwise to reduce the current to the motors. You shouldn't need to turn the screw much, though it is a bit of a trial and error approach.

It is usually easiest to do this with everything plugged in and EQMOD running so that you can feel how hot the motors are and go through a process of: adjust the screw, wait 30 seconds or so for the motors to cool down a bit, and repeat. Once the motors are not above 40 degrees C or so, you should be fine. The motors can run happily up to 85 degrees C or more without damage.

I think on future versions I will drill two holes in the top to allow the potentiometers to be turned without taking the box apart (you may wish to add these as well).

Tom

[chrisshillito]

Once I have polar aligned the telescope( I like to do that manually but know I can use EQmod to help with this if needed) and set that as my home position, can I unlock RA and DEC and move manually to a star to centre it in the eye piece and sync to it to create an alignment point, OR- do I have to issue a "go to" command to that star and then hit sync to set it as an alignment point?

The home position is separate from any position you may have to place the mount in to perform polar alignment. It is the position where telescope points at the pole with the telescope 'straight up' and the counterweights straight down. i.e. like this

http://www.firstlightoptics.com/user/products/large/skywatcher_eq5_goto_synscan.jpg

The home position never varies - you can't change it, you can set custom park positions but these are separate from the home position which has a special meaning. When you power cycle the AstroEQ it resets both its RA and DEC  position counters (encoders) to zero - and when EQMOD reads a zero position for both encoders it assumes the mount is at the home position.

So by putting the mount in the home position and power cycling AstroEQ you actually synchronising the starting positions of AstroEQ to EQMOD. When you then tell EQMOD to move to an alignment star EQMOD knows how much to moves each axis. In most cases EQMOD will get you close to the initial star but not spot on - this will be because the home position wasn't quite perfect or because of cone error etc. So you position the star in a reticule eyepiece or whatever and sync. When you sync EQMOD is told the actual RA/DEC coords of the sync point and knowing that it can work out how much the goto was out - this data then forms a point in the alignment model.

Now as soon as you slacken the clutches and manually move the mount EQMOD and AstroEQ loose track of where the mount is in the sky. Lets imagine you powered up in the home position and then slackened off the clutches an moved to vega as an alignment point. You then tighten everything up an sync. EQMOD gets told that it is pointing at Vega - but AstroEQ is telling EQMOD it is still pointing at pole because it hasn't move the mount itself. In this case the difference is huge and EQMOD suspects that something bad has happened so may reject the sync.

So the key points are:

1: start in the home position to get AstroEQ and EQMOD in sync with each other

2. Issue a goto so that AstroEQ moves its motors to where the sync target is supposed to be

3. Centre you alignment star and issue a sync so the EQMOD /AstroEQ is in sync with the actual sky.

Now lets look at custom park positions. To set you first custom park position you must have first powered up in the home position so the AstroEQ and EQMOD were in sync. Then slew the mount under EQMOD control to your desired park position and press the add park button. Form that point onwards, and assuming you always park the mount before power off and do not manually move the mount in anyway, you can power up in you custom position and unpark and EQMOD will preset AstroEQ's encoders such that they are in the correct position - so you no longer need to start in the home position but can instead start from you custom park position.

I take it I can then select in cdc another target and issue a slew command in cdc to "go to" it from that star selected as my first alignment point.

Yes. and if there is still a positioning error you just centre the second star (under EQMOD control) and sync to improve your  pointing model further.

Also wanted to create a pec file with my webcam to use it to correct any pec errors in my gears but that's another learning curve along with pulse guiding and everything else. However I am loving all these features it has to offer.

If you take the latest development version of EQMOD from the EQMOD yahoo group you will find it has an autopec feature which allows PE recording and PEC generation whilst you are guiding/imaging. Documentation for this feature is in the yahoo group files/documentation folder.

Finding your videos very helpful because being dyslexic I learn from visual input much quicker.

The videos are a little rough and ready and I couldn't be bothered with editing out all the ums and errs, which I do suffer from ans some find annoying.  Most folks learn quicker and better from being shown something than reading about it as Images stick in your memory much better than words. Certainly since recording the videos there have been significantly fewer support requests on the EQMOD Yahoo group.

[Oily]

Thanks Chris,really explains a lot

Point no.3

3. Centre you alignment star and issue a sync so the EQMOD /AstroEQ is in sync with the actual sky.

After you've slewed to your first alignment star and it's not spot on,do you use EQMOD or do you release the clutches,move the mount manually to centre the star then issue a sync?I've been doing the latter tbh

[Quatermass]

Thank you for that Chris, My understanding is that the home position then is like a car in the garage and when you start up the software it uses this to mark its position in ASTROEQ eq and EQMOD but the home position is not the position of a correctly polar aligned telescope. If it is though, then doing a manual polar alignment first, then powering up would be the same? After that moving and parking under the control of the software you can create a parked position where you like.

Your videos are fine and I allways prefer a visual method of learning if possible, I think lots of people do even if they don't have dyslexia as its a quick way to learn. Mind you people learn in many ways. I trained to be a level two angling coach several years ago and a big part of the training was understanding how people learn things. Visual learning, Auditory and written methods and I found my preference for visual learning aids was very popular with my students.

EQmod has a great deal of information to take in but your doing a great job at making it easier to get to grips with.

cloud cloud go away come again another day

[Quatermass]

Actually finding all this out about how eqmod and ASTROEQ function makes me very glad that I made the effort to build myself an observatory. Doing all this without being able too have the telescope in a permanent position would be a bit of a choir.

And to think I once said I would never use a laptop lol

cloud cloud go away come again another day

[Gina]

If I may jump in here - ALWAYS use EQMOD to adjust you mount/telescope once you have things set up.  Otherwise all your carefully obtained setting data will be lost.

[Quatermass]

I guess unlocking and moving manually is like jumping off the ship

cloud cloud go away come again another day

[chrisshillito]

After you've slewed to your first alignment star and it's not spot on,do you use EQMOD or do you release the clutches,move the mount manually to centre the star then issue a sync?I've been doing the latter tbh

For the very first alignment point you can do either or both (i.e. manually move to get it close and then fine adjust using EQMOD to get it centered). You still must do the initial goto though and only correct the error this way. In effect by manually adjusting the mount you are manually removing a home position error, if you correct under EQMOD control instead then EQMOD is just measuring that error and will compensate subsequent gotos accordingly. In theory it makes no difference but if you can remove as much setup error as you can manually then EQMOD doesn't have to compensate for it late an that can't be bad. For all subsequent alignment points you must not slacken the clutches - indeed don't slacken the clutches under any circumstances when using EQMOD from that point onwards.

Chris.

[chrisshillito]

Thank you for that Chris, My understanding is that the home position then is like a car in the garage and when you start up the software it uses this to mark its position in ASTROEQ and EQMOD but the home position is not the position of a correctly polar aligned telescope. If it is though, then doing a manual polar alignment first, then powering up would be the same? After that moving and parking under the control of the software you can create a parked position where you like.

The problem is a correctly polar aligned telescope (as opposed to mount) can be pointing in any angle of RA  - point at the pole and no matter where you put the RA axis you are still pointing at the pole. So if you polar align your mount using the polarscope method you could end up the RA Axis in any position depending on when you did it. When at the home position the telescope will be pointing at the pole but the RA Axis is in a very specific position i.e. such that the counterweights are pointing north and straight down. So after polar aligning you should return the mount to its home position and use that as a stating point for EQMOD and AstroEQ.

As you're  mount is in an observatory do you really need to be polar aligning every time? If not then you can just park the mount at the end of your session (to home or a custom position) and then the next session you just unpark. What is more you can have EQMOD automatically load your previous alignment model (there are options to save to load) when you unpark.

Chris.

[Gonzo]

As you're  mount is in an observatory do you really need to be polar aligning every time? If not then you can just park the mount at the end of your session (to home or a custom position) and then the next session you just unpark. What is more you can have EQMOD automatically load your previous alignment model (there are options to save to load) when you unpark.

 

Chris.

I curse everyone with a home observatory .....

[Quatermass]

Lol I cursed them as well

Sent from my GT-S5670 using Tapatalk 2

[Quatermass]

The problem is a correctly polar aligned telescope (as opposed to mount) can be pointing in any angle of RA - point at the pole and no matter where you put the RA axis you are still pointing at the pole. So if you polar align your mount using the polarscope method you could end up the RA Axis in any position depending on when you did it. When at the home position the telescope will be pointing at the pole but the RA Axis is in a very specific position i.e. such that the counterweights are pointing north and straight down. So after polar aligning you should return the mount to its home position and use that as a stating point for EQMOD and AstroEQ.

As you're mount is in an observatory do you really need to be polar aligning every time? If not then you can just park the mount at the end of your session (to home or a custom position) and then the next session you just unpark. What is more you can have EQMOD automatically load your previous alignment model (there are options to save to load) when you unpark.

Chris.

Brillant thank you very much Chris

Sent from my GT-S5670 using Tapatalk 2

[Quatermass]

Tried all the above instructions out tonight and worked like a dream. I hate to rub salt in the wound Gonzo but I am loving my rough and ready made observatory, it was easy to build from just a wrecked old shed took me one week so sure you could do the same. With ASTROEQ and EQMOD I am having a great time

cloud cloud go away come again another day

[TCWORLD]

Something to note that one AstroEQ user has discovered:

In EQMOD there is a slider labelled "Goto Rate Limit" under "Other Settings". Make sure that this is set to "No Limit", otherwise EQMOD will try to limit the goto speed in a way which is incompatible with AstroEQ. While it works fine when running, at the end of the goto, the mount will come to a dead stop (no gentle deceleration) which could cause issues if the scope is quite heavy.

I have an idea why there is no gentle deceleration with rate limiting on, but I am not sure yet how best to cure the problem. Hopefully in a future AstroEQ firmware release this will be fixed.

[chrisshillito]

Something to note that one AstroEQ user has discovered:

In EQMOD there is a slider labelled "Goto Rate Limit" under "Other Settings". Make sure that this is set to "No Limit", otherwise EQMOD will try to limit the goto speed in a way which is incompatible with AstroEQ. While it works fine when running, at the end of the goto, the mount will come to a dead stop (no gentle deceleration) which could cause issues if the scope is quite heavy.

I have an idea why there is no gentle deceleration with rate limiting on, but I am not sure yet how best to cure the problem. Hopefully in a future AstroEQ firmware release this will be fixed.

Hi Tom,

That is odd - EQMOD doesn't do anything particularly unusual when using a limited goto speed. All it does is set the mount moving at your chosen rate and then watches for the "encoder" values to get near to the target at which point it issues a stop followed by the usual slew to an encoder position. This final slew isn't rate limited and is left up to the mount controller to choose a rate - with the synscan this approach works because for small distance slews it chooses to use slow rates. Does AstroEQ respond to a stop request by applying a controlled deceleration or does it stop it dead?

If you haven't done so already it perhaps would make a nice addition to the AstroEQ setup utility if folks could specify a max slew speed that AstroEQ would apply when moving to a set encoder position (i.e. J command received after H command) . I know some folks in very cold locations prefer to slew at lower rates. Such a feature would remove the dependance on EQMOD's approach which, whilst it is the best we can do with the synscan, does run the risk of an uncontrolled/unending movement if comms should fail.

Chris.

[Gonzo]

I wonder if you could use https://code.google.com/p/indi-skywatcherprotocol/ with it

[chrisshillito]

I wonder if you could use https://code.google.com/p/indi-skywatcherprotocol/ with it

Not sure what you mean. AstroEQ already implements the synta/skywatcher protocol in order to interface with EQMOD.

Chris.

[Gonzo]

Not sure what you mean. AstroEQ already implements the synta/skywatcher protocol in order to interface with EQMOD.

Chris.

It's to run it under Linux

[TCWORLD]

Hi Tom,

That is odd - EQMOD doesn't do anything particularly unusual when using a limited goto speed. All it does is set the mount moving at your chosen rate and then watches for the "encoder" values to get near to the target at which point it issues a stop followed by the usual slew to an encoder position. This final slew isn't rate limited and is left up to the mount controller to choose a rate - with the synscan this approach works because for small distance slews it chooses to use slow rates. Does AstroEQ respond to a stop request by applying a controlled deceleration or does it stop it dead?

If you haven't done so already it perhaps would make a nice addition to the AstroEQ setup utility if folks could specify a max slew speed that AstroEQ would apply when moving to a set encoder position (i.e. J command received after H command) . I know some folks in very cold locations prefer to slew at lower rates. Such a feature would remove the dependance on EQMOD's approach which, whilst it is the best we can do with the synscan, does run the risk of an uncontrolled/unending movement if comms should fail.

Chris.

Hi Chris,

The AstroEQ configuration does allow a max speed for Goto commands to be set, so this should be used instead of the rate limiting.

When AstroEQ receives a stop command (K), it calculates the current speed and a deceleration curve from that speed to 0. The trouble is that with the rate limiting, it appears that EQMOD sometimes sends the stop command twice. When the second stop command is received before the mount has actually slowed to a stop, there is a glitch in the AstroEQ firmware which causes the mount to stop dead (no deceleration).

I had come up with a possible fix whereby after the first stop command, AstroEQ ignores all stop commands until the mount has finished decelerating. Unfortunately that didn't work as it led to situations where EQMOD is tricked into thinking the mount has stopped when actually it is still going.

[JamesF]

It's to run it under Linux

Run what under Linux?

James

[TCWORLD]

Chris,

I've attached a text file which is debugging data from AstroEQ during a rate limited goto. I've labelled the important bits and the area that causes the problem.

Limited Goto comms dump.txt

[TCWORLD]

Run what under Linux?

James

Its a native Linux program which can be used to control Skywatcher mounts. I think Gonzo was asking whether it would be able to control an AstroEQ modded mount, to which the answer is yes it would. Any software which works with a skywatcher synscan mount should also work with AstroEQ.