Guiding conversion project for 200p and EQ5

[Quatermass]

Ok tonight was tantilizingly close to getting what I wanted but rain and clouds spoiled my fun so was not able to really get to grips with things. However putting the guide camera on the main telescope and piggy backing my lumix G1 and taking a guided 4 minute exsposure 4 mins is all the lumix will do on bulb gave me this shot. I have zoomed in on Betelgeus so you can see how nice and round it is.

Seeing that it was guiding and finding a star ok I decided to hastily put together a tiolet roll diy effort so I could get the guide camera in the finder scope with my bit of foam. I managed to focus and got a star to guide with then wapped on my cannon 350d. The lvi started to guide and I thought I was in business but the clouds rolled in at 93 seconds and I lost the star and that was that grrrrr.

How annoying was that 93 seconds, it started to rain after that so this was all I got. My scope want level my polar alignment was rubbish and with a tiolet roll for a focus holder it has been quite an evening.

Any way it guides but it wont move the motors when it starts to calibrate for some reason keep getting the motors not moving error message but when I by pass that and press load it start to guide weird.

Well had enough for tonight I cant honestly say I am finding guiding for the first time a whole lot of fun but I like the challenge.

[Quatermass]

Well in regards to the motor not moving error message on the LVI autoguider I got this reply back from LVI today. Its depressing.. very depressing

Hello,

Thank you for explaining your problem so much in detail!

The Shoestring mod with EQ5 dual axis drive just allows the autoguider "virtually pushing" the buttons on the keypad through the ST4 port.

The problem you are having with your Smartguider while calibrating is a too fast guiding rate causing the star running out the image sensor in a few seconds.

I guess the slowest speed is 1x with your EQ5 drive, that is just too much for all the autoguiders in the market!

Although you were able to calibrate, the autoguiding would have been rough with growing overcorrection.

I suggest to buy the Synscan kit for your mount replacing the EQ5 modded drive, so you can flawlessly use your Smartguider and have also a goto system as a bonus!

I don't know any other valid solution, hope this helps.

NO it does not help it makes me want to cry!

However I also found this thread on the LVI smart guider as well from a guy who had been using it for over a year..

I have been using LVI Smartguider for over 1½ years and I got that working with lots of effort too. But after this tuneup my LVI did its' job quite well, when I had learned the right settings for my imaging system. I have been using it with this setup (12" (f5) Newtonian scope plus 4" (f9) guide scope), but quite recently I've sold the LVI Smartguider unit and moved into an OAG setup with the SX Lodestar guide camera. (I noticed that I needed a more sensitive guide camera for OAG purposes as LVI did not find any guide stars from my OAG port views. The SX Lodestar has no issues with this anymore

Some advice about the "MOTORS NOT MOVING" error as I got that too in the beginning. I managed to solve that by changing my guide rate to 0.25x - 0.40x sidereal rates. If I understand this correctly, this error comes when the guide camera does not see the star moving. There are two reasons for this:

1.) The guide rate does not deviate enough from the stardard 1x sidereal rate. This can happen, if the guide rate in your mount is too near to 1x sidereal rate (ie. between 0.5x - 0.9x). "MOTORS NOT MOVING" error vanished right after I drop my guide rates into the low 0.2x - 0.4x area.

2.) The second reason for this error can be an excessive backslash with mount RA gears. This way the mount gears move some time empty, when the guider (mount gears) change direction and after some period of time the guider gives "MOTORS NOT MOVING" error.

From my point of view both LVI Smartguider (and the almost identical Orion Stand Alone Solitaire autoguider) are crippled by their "not-so-sensitive" guide cameras (CCD sensors). These devices could also use a better view with the guide stars ie. these devices should display all the stars in the hand unit' display (from the CCD sensor's view) and let the user to select the best guide star for guiding. LVI Smartguider is quite demanding with its' guide star brightness and thus I used an oversized guide scope with my setup. With bright guide stars all is working with good accuracy, but with dimmer ones (below 6...7 mag) problems starts to rise

BTW. Most of my astrophotos on my web site are taken with the help of this LVI guider. There's also a l-o-n-g thread from this LVI unit on our Finnish astronomy forum, which can be read from here. It's in Finnish, so you might want to use Google Translate with it (link) as the Finnish language is mostly illegible to you folks...

(Oh, "digijärkkäri" means "DSLR" in the translated text...)

[Quatermass]

I find this whole thing really frustrating beginning to wish I had not bothered now and saved up for the HEQ5 mount instead as according to LVI the EQ5 conversion is not going to work with my autoguider and if the speed of my tracking motors at 1x is too slow for all the autoguiders on the market as this guy is telling me then I have just wasted my money time and effort! However I also read on another thread of a guy who could lower the tracking speed on his mount to lower then 1x and despite that and everthing else he still got the motor not moving message so I just dont know who to belive here.

Its begining to look like Stans way of doing it via a laptop is the only way forward as this mod does not seem to like autoguiders. Would be intresting to hear from any one out there who had done the mod and is using and autoguider as well.

If this means using my laptop then for get it I dont want to be bothered with all that hassle.Is the guy from LVI right or would a different autoguider work who knows but Im done spending money on this.

[malc-c]

I find this whole thing really frustrating beginning to wish I had not bothered now and saved up for the HEQ5 mount instead as according to LVI the EQ5 conversion is not going to work with my autoguider and if the speed of my tracking motors at 1x is too slow for all the autoguiders on the market as this guy is telling me then I have just wasted my money time and effort!

Sorry to hear that. Using software such as EQMOD you can set the pulse width from 0.1 to 0.9 which I assume means 0.x sidereal rate. But then that is what's used to control the mount rather than pseudo pressing buttons with the hand controller that cant be set to anything other than sidereal rate ...

Don't know what to suggest other than try and source a second hand EQ5 Synscan unit and use that... or as you say, invest your cash in a secondhand HEQ5 syntrek version

As for the expense, afraid to say that it goes with the territory when developing any modification. My HEQ5 belt mod has set me back a fair bit and that was with the help of another SGL member doing some machining for me.

[Quatermass]

Your right malcom it is a money gobbling hobby at times. Well its not all bad I have a nice dual axis motor kit on my eq5 with the possiblity of doing what stan has done if I decide to get a laptop setup. Looking on the net at the LVI autoguider it seems to have a mixed following some say it works great others say it was not so great I guess it depends on your set up.

Well I dont know what to do now, I can continue experimenting with my LVI and see if I can get any better results. My shot that was piggy backed for 4 minutes came out very well with no trailing but that might not be the case when I am imaging through the telescope for longer exposures. Back to the drawing board I guess. Sigh..

[RikM]

I hope you get something sorted but wouldn't read too much into your piggy back shot coming out so nicely. With a camera and lens you can get quite long exposures even unguided if your PA is close enough. Your PA must be good to get the unguided shots you have been getting.

If you fancy a break to give yourself time to relax try bolting your camera on to dovetail bar and just take unguided widefields. With your good sky and good PA and with the shorter focal length and less weight on the mount (without the scope) you should get some great shots.

I can get a good 3 min with a 300mm lens unguided on an EQ3-2. e.g.

Edit: another image upload gets an extra stretch thanks to SGL. This looks fine hosted elsewhere, here it's got nasty vignetting

Edited January 28, 2012 by RikM

[Quatermass]

I hope you get something sorted but wouldn't read too much into your piggy back shot coming out so nicely. With a camera and lens you can get quite long exposures even unguided if your PA is close enough. Your PA must be good to get the unguided shots you have been getting.

If you fancy a break to give yourself time to relax try bolting your camera on to dovetail bar and just take unguided widefields. With your good sky and good PA and with the shorter focal length and less weight on the mount (without the scope) you should get some great shots.

I can get a good 3 min with a 300mm lens unguided on an EQ3-2. e.g.

Edit: another image upload gets an extra stretch thanks to SGL. This looks fine hosted elsewhere, here it's got nasty vignetting

Hi Rik

That sounds like a good idea! This guiding project is stressing me out some what lol.

Im still not convinced that the LVI guy has got it right about the motor speeds after all Stan is using the dual axis kit and its working for him. I think this is more an issue with the LVI guider its self to be honest.

Not giving up on this I will have a guiding system by hook or by crook. Nice image mate

[malc-c]

I've been gogling around and it would seem that the Smart guider has a fixed pulse of 500mS, which is probably why when calibrating is causing the star to move out of the field of view. Without hacking the firmware I doubt if there is much that can be done.

The SmartguiderII however has variable pre-set pulse durations but even their manual is confusing. The table states 25, 50, 100, 250 and 500 mS but the text below this describing the menu option states allowed values are 30, 60, 125, 250 and 500 ms ????

[Quatermass]

Not sure what you mean there Malcom

What is a fixed pulse of 500ms and what would that do? sorry I am so not a technically minded person at all.

[Quatermass]

reading about the tracking speeds needed by the lvi, the tracking speeds on an eq6 are

0.25X, 0.50X, 0.75X, or 1X but on the eq5 dual axis motors the manual say this...

The tracking speed of the R.A. motor is factory set and

should not need adjustment. Adjustment of the variable

resistor inside the control box should be preformed by an

experienced technician

However it does not tell me if the "tracking speed" that is factory set is the same as the 2X/4X/8X switch on the dual axis control pad that changes "rotation speed" used by the control pad

is tracking speed and rotation speed the same thing???

Heres the blurb from the manual

The N/Off/S switch acts as a power switch as well controlling

direction of clock drive. The "N" position allows R.A. motor

to track for Northern Hemisphere observing and the "S"

position is suitable for the Southern Hemisphere. The

2X/4X/8X switch changes rotation speed used by the control

box buttons. It sets rotation rate for multiple of tracking speed.

The up-down buttons control the declination motor while the

left-right buttons change the R.A. axis.

Edited January 28, 2012 by Quatermass

[Quatermass]

Well I suspect most people have now glazed over on following this thread it certainly is making me tired I can tell you. However to freshen things up here is one of the best blogs articles I have read about guiding sytems while I am still trying to figure out how to get mine off the ground

Uncle Rod's Astro Blog: Uncle Rod?s Telescope Academy: The Autoguiding Auto de fé

[malc-c]

Ok the motor system you have is designed to track at 1x sidereal rate which is 15 degrees per hour. The 2x, 4x and 8x switch, depending what you've selected, makes the motors move the axis at 30, 60 and 120 degrees per hour, presumably when the NSEW buttons are pressed.

So when the autoguider sends a half second pulse (500ms) to the ST4 port, it's like holding down one of those buttons for half a second, which at 2x (the minimum) will make the mount move through 0.004 of a degree (if I got my maths right). My guess is that this translates it to an angular arc that moves the target star too far out of the field of view.

Obviously the idea of guiding is to keep the target star as central as possible with as little movement as possible by sending very small pulses that's enough to place the star back in the centre, ideally without overshooting. As I'm using a different mount, and software to control the scope it's difficult to comment on how the LVI system works, but my guess is that when used with a mount that has a proper ST4 port, the 500ms pulse it would translate into a smaller pulse at motors.

One final thought, when running the calibration was the handset set to 2x - if it was set to 8X that might explain things

[Quatermass]

I tried the calibration with it set at 2x it still came up with the motors not moving message so I presume that 2x is still too much and is moving the star too far out?

The support guy from LVI said, I guess the slowest speed is 1x with your EQ5 drive, that is just too much for all the autoguiders in the market!

When he said its too much for all the auto guiders in the market, did he mean that that 1x is too fast an adjustment to keep the star in the cameras view?

I dont understand then what is going on when I ignore the calibration step and press load. The thing starts guiding here is shot of it doing just that.

So what is it doing here guiding really badly or just guiding??

The LVI also said this:Although you were able to calibrate, the autoguiding would have been rough with growing overcorrection.

Edited January 28, 2012 by Quatermass

[Quatermass]

If I am understanding all this correctly, the bottom line is the guiding speeds of the dual axis motor kits gears are too high for an autoguiding system. And if that is the case how come Stan is able to guide with phd and the laptop and webcam??

[malc-c]

I'm also at a loss - I think the problem is that if your motors are tracking at sidereal rate, the minimum setting the handset has is 2x rate. So when a pulse is sent to a direction pad it will either advance that to 2x sidereal in one direction or track it at 1x sidereal in the other, ie sorta -1x sidereal.

Might help you understand the concept and work out whats going wrong with the modded handset

Edited January 28, 2012 by malc-c
wrong link

[Quatermass]

Thats an interesting mod on the gears looks pretty cool as well. I dont know Malcolm I think the issue here is the guiding speeds are just wrong for the LVI calibration step. Its all becoming far too much hassle for me at the moment I like things to be easy and straightforward and this is anything but. I cant imaging using phd and a laptop being any less complicated in terms of getting it all set up.

I did a search and found a chap on this forum who had got the HEQ5 and the LVI auto guider and his report showed it all working fine with that mount. I would like to send you the LVI guider and let you have a go with it to see if it works ok with your set up. You have a guide scope and st4 port I take it?

[stan26]

Hi QM, Sorry to here about this problem, it may be a major one to! Maybe I was to quick to encourage you to go ahead with my rose tinted EQ3-2 setup glasses on

I assumed the LVI would guide as any other guide program would albeit in a slightly different format, but obviously not. Were these units really designed/marketed only for percific makes and/or models of mounts..? Surely all mounts have slightly different slew rates...?

Anyway, If the LVI has a set pulse rate then its probably game over for successful guiding. I know this isn't what you want to hear mate. I'm sure you could sell the LVI and have more than enough funds to get a suitable webcam. I got mine for around a fiver! Then you need an iterface. My serial interface was around £40 shipped from USA.

PHD is an awesome bit of kit, its free (but you can donate) and its very simple, and loads of people use it so theres loads of help available. IMO laptop/PC guiding is the way forward and besides ultimate portability offers the imager a lot more flexibility when fine tuning the whole setup, plus with additional extension cables (I got for a tenner from UK) you can sit in the warm indoors getting on with other things whilst keeping an eye on screen!

I hope somebody comes along soon with a simple cheap solution for your LVI but if not its not the end of the world, just another set back in the slippery slope to guided imaging. The PHD route is still going to be a lot cheaper than the HEQ5....

Stan:icon_confused:

Edited January 28, 2012 by stan26

[Quatermass]

Don't give up QM!, I'm sure you can tweak things. Unfortunately I know diddly squat about the LVI, but surely you can adjust the command input settings? i.e guide pulse aggressiveness/duration etc...? I'm still getting to grips with PHD but I have the HC set to 4x speed, but I think any speed would work.... I'm not sure if all the various guiders/softwares account for set slew speed during the calibration process...?

If you do decide to go PHD/webcam its a mega cheap solution. The interface port will be your only real cost (and obviously you'll need a laptop or nearby PC)

Stan.

Hi Stan

I'm not giving up having come this far that for sure, having got this far I have come up against the first set of problems and they are all centred around the LVI auto guider.

Another chap on the forums from an older thread posted that he was using the LVI and the HEQ5 with no problems and getting good results. But, and here is the issue for me, the gears that come with the EQ5 dual axis motor kit dont have the guiding rates of the HEQ5 which are, 0.25x 0.5x 0.75x and 1x the LVI calibration process will give you a "Motors not moving" error message unless you lower the guiding rate down to 0.25/

SO as the guiding rate for the EQ5 dual axis motor kit gears is factory set to god knows what I cant change them.

Result of all that is the LVI auto guider will not calibrate correctly and any guiding going on is going to be to rough.

I have no experience of PHD or other computer related software for guiding but it would seem that it is doing a fine job for you with your dual axis kit so may be the best option. Given that auto guiders are supposed to be all singing all dancing solutions I have to say I am disappointed that the LVI can cope with a higher guiding rate.

Still looking on the positive side I have learned a great deal from doing the mod to my EQ5 mount and found out more about using the finder scope as a guide scope as well.

Question for me now is do I keep trying to get results from the LVI with my set up or forget it and turn my attention to the PHD laptop setup that you have working for you. With the EQ5 modded already I cant see any other option but to try it out.

[stan26]

If I am understanding all this correctly, the bottom line is the guiding speeds of the dual axis motor kits gears are too high for an autoguiding system. And if that is the case how come Stan is able to guide with phd and the laptop and webcam??

This is because the user can tweak all the settings in PHD to set the guide command pulses, i.e the aggessivness of the command and the duration of the command. The mounts motor speed doesn't really matter, PHD will deal with it.

Stan

[Quatermass]

The LVI does have an option to set the aggressiveness here is what it says in the manual.

From the autoguiding screen, pressing the ADVAN menu item brings up the

advanced settings screen:

EXIT will take us back to the previous menu, while by pressing AGGRESS X we

come to the following screens:

With the two triangular arrows (UP and DOWN), you can adjust the

aggressiveness in the X axis (upper left) and in the Y axis (upper right).

The aggressiveness in both axes can range from 1 to 6 (1-2=LOW, 3-4=MILD, 5-

6=HIGH) and expresses the degree of reactivity of corrections: a high value will

urge the camera to immediately correct for the slightest displacement, whereas a

low value will yield a much smoother behavior. See more details at page 10.

I have done this and set it to 3 a medium rate but if it by passes the calibration set up will that make any difference I just dont know.

[Quatermass]

And the rest from page 10

4.5 Mount calibration

The telescope must not be touched during calibration, otherwise the relevant

parameters could not be calculated correctly. This also applies to the Control

Paddle unit which must not stay in your hand!

Once calibration is over, the parameters are permanently stored into the

SmartGuider’s internal memory (EEPROM) for later use, provided that the

following precautions are taken into account:

1. Always guide on stars lying in the same side of the sky (with respect to the

local meridian) as that where the calibration was last performed;

2. NEVER take the camera off the guide scope;

3. NEVER rotate the camera in the guide scope focuser.

In all other cases, the camera must always be recalibrated.

It might take a relatively long time for the calibration process to complete,

especially with guide scopes of short focal length (under 500 mm).

It is also advisable not to use too dim a star for calibration, otherwise just a few

thin clouds or a little dew on the lenses could cause the star to be lost and

jeopardize the final result of this important process.

4.6 Autoguiding and aggressiveness

In practice, the aggressiveness parameter defines the “reaction threshold” (in

terms of sensor pixels), i.e. the value of the offset between two consecutive

exposure cycles above which the camera will make a correction.

The lower the aggressiveness, the higher the tracking error allowed and viceversa.

HIGH values are suitable when using small refractors featuring a focal length

1,5-2 times smaller than the main instrument. MILD values are for guide scopes

of about the same focal length and LOW ones are best in case of very long guide

scopes or off axis guiding (typically SCTs).

During autoguiding, the trend of the X and Y graphs should always be staying

as smooth as possible. It is advisable to start off with default values for

aggressiveness and guiding speed; then both parameters can be fine tuned to

achieve the best possible sync between your SmartGuider and your telescope.

If you notice any significant oscillations about the zero position of one or both

graphs (overcorrection), the guiding speed should be decreased with the mount

drive keypad until the oscillation becomes less important (ideally, almost

negligible). Anyway, it must be noted that a little oscillation across the zero line is

acceptable since both graphs depict the offset between two consecutive

exposures with a 2X scale. So, two pixels on the tracking graph are actually

equivalent to one single pixel on the detector. If the oscillation continues even

with the guiding speed at its lowest possible value, the aggressiveness has to be

decreased.

In case the profile of one or both graphs keeps steadily above or below the zero

value (undercorrection), the guiding speed has to be slowly increased until the

graph profile goes back to hovering around the zero position. If no improvement

is seen even with the guiding speed at its highest value, the aggressiveness must

be increased.

On nights of bad seeing, and especially with long focal length guide scopes, it

could be worthwhile to slightly defocus the guide star, so that the effect of highfrequency

twinkling is mitigated somewhat and the camera won’t try to “guide the

seeing out”.

Should the graphs still be showing a small, jerky oscillation in spite of the above

precautions, please make sure your equipment is properly balanced in both axes.

It must be stressed that a perfect balance of all the weights, the quality and

solidity of all the mechanical supports and adapters is of paramount importance

in getting round stars and well-tracked exposures! Sometimes, trailing due to

differential flexure can ruin your pictures even with apparently smooth tracking.

[stan26]

Don't give up QM!, I'm sure you can tweak things. Unfortunately I know diddly squat about the LVI, but surely you can adjust the command input settings? i.e guide pulse aggressiveness/duration etc...? I'm still getting to grips with PHD but I have the HC set to 4x speed, but I think any speed would work.... I'm not sure if all the various guiders/softwares account for set slew speed during the calibration process...?

If you do decide to go PHD/webcam its a mega cheap solution. The interface port will be your only real cost (and obviously you'll need a laptop or nearby PC)

Stan.

Hi Stan

I'm not giving up having come this far that for sure, having got this far I have come up against the first set of problems and they are all centred around the LVI auto guider.

Another chap on the forums from an older thread posted that he was using the LVI and the HEQ5 with no problems and getting good results. But, and here is the issue for me, the gears that come with the EQ5 dual axis motor kit dont have the guiding rates of the HEQ5 which are, 0.25x 0.5x 0.75x and 1x the LVI calibration process will give you a "Motors not moving" error message unless you lower the guiding rate down to 0.25/

SO as the guiding rate for the EQ5 dual axis motor kit gears is factory set to god knows what I cant change them.

Result of all that is the LVI auto guider will not calibrate correctly and any guiding going on is going to be to rough.

I have no experience of PHD or other computer related software for guiding but it would seem that it is doing a fine job for you with your dual axis kit so may be the best option. Given that auto guiders are supposed to be all singing all dancing solutions I have to say I am disappointed that the LVI can cope with a higher guiding rate.

Still looking on the positive side I have learned a great deal from doing the mod to my EQ5 mount and found out more about using the finder scope as a guide scope as well.

Question for me now is do I keep trying to get results from the LVI with my set up or forget it and turn my attention to the PHD laptop setup that you have working for you. With the EQ5 modded already I cant see any other option but to try it out.

Is the motors not moving message due to backlash though? baring in mind that LVI is looking for movement in the guide star, it doesn't actually know what the motors are doing in real time, it just sents the set command and waits to see the results through the guide scope. The motor I dare say is probably moving at 1x, but just not enough to take up slack in the drive to move the mount. Does the LVI say in which AXIS is not responding during the cal, or does it just say motors not moving?

Its such a shame that the LVI looks like it won't work for you, its half way there on its own being a self contained unit, how frustrating must that be

I would start looking now for a cheap webcam. Ideally spc880/900 but there are others out there. Il see if I can dig up the thread i found on here that lists the older CCD webcams.

Have you got a laptop? If not you can use your PC if its not miles from your scope. If you need a laptop get on the local gumtree add site, theres some real bargains on there. My advise (to keep things simple) get a laptop with a 25pin db25 serial port. Most older PC's/laptops had them. This way you don't have to worry about additional ASCOM software (required for USB interfaces), the GPINT-PT serial adaptor I use from shoe string is pure "plug and play" no software needed, just switch on laptop/plug in webcam/st4 lead and fire up PHD done job!

HTH

stan

Edited January 28, 2012 by stan26

[stan26]

Hmm, I think your problem may be the "duration" of the guide pulse, and maybe not the aggressivness. I may be wrong here and hope somebody can come along to comfirm/correct this with answers for you. I guess you can't adjust this.

dam

[Quatermass]

The motors not moving message happens on the RA adjustment it never gets to the dec adjustment. I did think that it might be the RA motor having a blank spell before it started moving and this was suggested by a guy on another forum who said this..

Some advice about the "MOTORS NOT MOVING" error as I got that too in the beginning. I managed to solve that by changing my guide rate to 0.25x - 0.40x sidereal rates. If I understand this correctly, this error comes when the guide camera does not see the star moving. There are two reasons for this:

1.) The guide rate does not deviate enough from the stardard 1x sidereal rate. This can happen, if the guide rate in your mount is too near to 1x sidereal rate (ie. between 0.5x - 0.9x). "MOTORS NOT MOVING" error vanished right after I drop my guide rates into the low 0.2x - 0.4x area.

2.) The second reason for this error can be an excessive backslash with mount RA gears. This way the mount gears move some time empty, when the guider (mount gears) change direction and after some period of time the guider gives "MOTORS NOT MOVING" error.

[Quatermass]

Well Stan it might be worth trying a few more times but its pretty hit or miss and I want something that is more reliable for guiding with my set up.

I have a laptop I could get a webcam and order the adapter I also have a shed or a bivvy I could retire to with all that lot to keep warm... and go mad in there