Guiding conversion project for 200p and EQ5

[stan26]

Hmm, either way that LVI is probably asking to much of the EQ5 dual axis setup. I'm surprised they work as well as they do with HEQ5's....they will still have some backlash. Its just seems to particular for its own good.

BTW here is the webcam page link.

http://stargazerslounge.com/imaging-discussion/81143-alternative-philips-spc900nc.html

stan

[Quatermass]

Your right there Stan its a fussy little swine:mad: Im going to download PHD and have a look at it Also emailed my mate and asked for my fishermans bivvy back it would make a great shelter for a laptop phd set up and its portable.

Might need to pick your brains some more about it as I have never used it before.

As for the LVI what a temperamental little so and so..

[RikM]

I would say the 'motors not moving' error is due to backlash. A half second pulse is nothing when you have to hold the button for 2-3 seconds before the backlash is taken up. With an eyepiece in, how long do you have to press a button before you see movement?

[Quatermass]

I would say the 'motors not moving' error is due to backlash. A half second pulse is nothing when you have to hold the button for 2-3 seconds before the backlash is taken up. With an eyepiece in, how long do you have to press a button before you see movement?

Good point Rik when I was moving the RA and looking through the guide scope it took about 3-4 seconds before it moved sometimes

SO if it was back lash why would the LVI support guy say this..

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!

[RikM]

I think what he is saying is probably true to a point. The idea of guiding isn't to 'move the star back into the centre', it is to keep the calculated centre of the star within the borders of the airy disc so the star appears round within the seeing conditions. So a blip on the motors at siderial rate would probably lead to overcorrection, but I don't think it would be enough to loose the guide star off the chip.

I still think your current difficulty is down to backlash rather than guide speed. Once you have the backlash sorted with a tweak on the worm gear, then the guide speed issue will come back to bite you. I am afraid I don't know how the smart guider system works but I can't see how electronically pressing the handset buttons is going to give you pixel scale guiding with 1m focal length.

Sorry I can't offer anything in the way of a solution as I am a DIY muppet. I just point it at the sky and press buttons with my fingers crossed.

[Quatermass]

Thank you Rik

Well I just down loaded the guiding software PHD push here dummy and was shocked to see how simple the interface was compared to Photoshop it looks positively easy peezy I must admit I thought it was going to be some horribly complicated nerdy programme but its clearly not. Maybe getting tucked into a bivvy and using a a laptop would not be so bad after all. Maybe I could even use the LVI camera instead of a webcam?

[Quatermass]

LOL pointing at the sky and press buttons with my fingers crossed, me too

[malc-c]

If I understand this correctly guys, QM can't connect a laptop or computer to the EQ5 because he has the basic dual axis motor upgrade. This has no way of interfacing with a PC. The handset that comes with these motors will constantly track at sidereal rate, and using a combination of the switches track at 2x 4x 6x and 8x sidereal when the NSEW buttons are pressed. QM has modified this handset to add an ST4 port so that the output from the LVI autoguider can be connected. This (if my reading is correct) when sending a pulse down the ST4 cable puts voltage on the pads of the relevant switch which the handset interprets as button push and thus momentarily moves the mount at 2x sidereal in that direction. The problem QM is having is that whilst calibrating the target star is moved out of the field of vision, which the autoguider interprets as if the motors are not moving.

Whats required is to either be able to make the hand controller run at normal or 1/2 sidereal rate (difficult) or some how configure the autoguider to send shorter pulses. something which I think is only possible in the MKII version ?

As for the HEQ5, well firstly it has stepper motors with double the precision so can move smaller amounts. The combination of the handset and firmware on the motor board allows for the pulse width to be adjusted to fine tune calibration when guiding. This is more precise when using EQMOD and software running on a PC. Thus if using the LVI with an HEQ5 I have no doubt it would work given all the above.

I can only see two ways forward:

1) - look for a custom stepper controller schematic and build a dedicated controller - but this would need a lot of electronics experience and could be just as costly as the next option.

2) - buy the synscan upgrade, and use the dedicated ST4 port built in. It would be worth having it confirmed in writing that the LVI is compatible with the synscan - just in case

The later would also allow you to control the EQ5 from a computer and thus give you far more flexibility.

[RikM]

With PHD you choose your camera, chose your mount connection, press 'loop', click on a star, press guide and wait for calibration to finish, (takes a few minutes), when it's all done the crosshairs turn green and it says 'guiding' in the bar at the bottom. That's it. Press 'go' on your camera. ...even I can't screw that up too much.

[Quatermass]

If I understand this correctly guys, QM can't connect a laptop or computer to the EQ5 because he has the basic dual axis motor upgrade. This has no way of interfacing with a PC. The handset that comes with these motors will constantly track at sidereal rate, and using a combination of the switches track at 2x 4x 6x and 8x sidereal when the NSEW buttons are pressed. QM has modified this handset to add an ST4 port so that the output from the LVI autoguider can be connected. This (if my reading is correct) when sending a pulse down the ST4 cable puts voltage on the pads of the relevant switch which the handset interprets as button push and thus momentarily moves the mount at 2x sidereal in that direction. The problem QM is having is that whilst calibrating the target star is moved out of the field of vision, which the autoguider interprets as if the motors are not moving.

Whats required is to either be able to make the hand controller run at normal or 1/2 sidereal rate (difficult) or some how configure the autoguider to send shorter pulses. something which I think is only possible in the MKII version ?

As for the HEQ5, well firstly it has stepper motors with double the precision so can move smaller amounts. The combination of the handset and firmware on the motor board allows for the pulse width to be adjusted to fine tune calibration when guiding. This is more precise when using EQMOD and software running on a PC. Thus if using the LVI with an HEQ5 I have no doubt it would work given all the above.

I can only see two ways forward:

1) - look for a custom stepper controller schematic and build a dedicated controller - but this would need a lot of electronics experience and could be just as costly as the next option.

2) - buy the synscan upgrade, and use the dedicated ST4 port built in. It would be worth having it confirmed in writing that the LVI is compatible with the synscan - just in case

The later would also allow you to control the EQ5 from a computer and thus give you far more flexibility.

But Malcom by adding the ST4 port to it as I have done with the Shoestring astronomy kit I could now connect this to a pc if I got the adapter from shoe string as Stan has done and a webcam. Still a cheaper option then getting the HEQ5 and it seems to be working for Stan ok.

Has to be worth a try if the blasted LVI is going to be such a pain. And PHD looks very easy to use.

[malc-c]

let me read up on the shoestring kit - I thought all it did was provide an ST4 port connector with some cable.... If you can hook up a PC then I would suggest using EQMOD and a PC for control

EDIT:

I see you are referring to the GPUSB box for £80 - which then plugs into the ST4 cable you have added to the hand set... Yes cheaper than the Synscan upgrade... by around £100 !

Edited January 28, 2012 by malc-c

[Quatermass]

I also noticed that the qhy5 pin layout is the same as my lvi camera

So if thats the case I presume I could use that instead of a webcam once i bought the adapter for the ST4 cable to pc

wait a mo whats the other plug in bit?

[RikM]

USB.

You can do USB to PC and control via EQmod pulse guiding, or USB to PC and ST4 to mount and guide 'on camera'.

[Quatermass]

mmm mybe not as my LVI does not have that other slot which is for the power I guess. Still may be possible.. options options.

[Quatermass]

My LVI just has an ethernet connection how would that work out with PHD? In other words you plug this into the connection on the back which connect to the hand unit

Edited January 29, 2012 by Quatermass

[malc-c]

As mentioned the QHY5 has both USB and ST4 ports. Data from the camera is sent via the USB cable to the PC. The ST4 cable can be used as a means of transmitting the guide pulses to the mount. Or using ASCOM pulse guiding software on the PC does all the work and sends pulses via the EQDIRECT cable used to control the scope.

[Quatermass]

Well I am fast reaching the conclusion that using phd on a laptop is going to have to be my next option as I dont want to give up now because of the failings of the LVI autoguider and its inflexablity for my system. I feel a bit like this..

[austen4]

Its a shame quarter mass it does not work properly after all of that? I am going to try this with the HEQ5 with normal dual axis, I take it the guy off the other forum got it to work by doing everything you have done?

Thank you

[Quatermass]

Its a shame quarter mass it does not work properly after all of that? I am going to try this with the HEQ5 with normal dual axis, I take it the guy off the other forum got it to work by doing everything you have done?

Thank you

Hi Austen

I think the problem is the LVI auto-guider not my modding the eq5 dual axis kit with the st4 port that work fine. I think from what Stan has done that using PHD on a laptop with a webcam on the finder guider would work but the LVI is far too fussy despite its cost glad it was a gift! It will work with the HEQ5 for sure though fat lot of good that is for me..

Any way must stay positive the mod is done and if it will work on phd laptop and webcam that's still got to be better Stans works so I dont see it not working for me and I have nothing to lose by trying as I want a webcam anyway and the adapter is not much.

[Quatermass]

He who dares wins Rodney he who dares wins...

[austen4]

Hi Austen

I think the problem is the LVI auto-guider not my modding the eq5 dual axis kit with the st4 port that work fine. I think from what Stan has done that using PHD on a laptop with a webcam on the finder guider would work but the LVI is far too fussy despite its cost glad it was a gift! It will work with the HEQ5 for sure though fat lot of good that is for me..

Any way must stay positive the mod is done and if it will work on phd laptop and webcam that's still got to be better Stans works so I dont see it not working for me and I have nothing to lose by trying as I want a webcam anyway and the adapter is not much.

Hello,

Thanks for the reply. The mod seems simple and as you said that wouldnt be the problem. What webcam does he use with his finder guider? I have seen some of the prices which on top of a goto has made me want to do the mod.

I hope you find a way to fix it. You have enlightened us all!

Thanks again

[Quatermass]

Cheers Austin I dont know what webcam he is using think it was a logitic one but you wont need an expensive one. Hope this thread has helped other a bit it certainly is a steep learning curve but like they say no pain no gain. Off to bed now to dream of working guiding systems lol

[austen4]

Hello Quartermass,

Would you be able to ask him as I am trying to save as money as possible? If its not to much to ask. One day you will my friend.

Thank you

[stan26]

Made a pretty picture on paint to try and help people understand my setup.

I use a standard unmodded logitech quickcam pro 4000. Its an early model with the SONY CCD sensor.

I use a GPINT'PT serial interface adaptor available from shoestring astronomy to connect to my laptop. Its plug n play, no additional drivers/software needed. I think people need to use ascom withthe USB versions. To me thats another program to get my head around so I stuck with good old serial port interface.

I also had a modded st4 port handcontroller as per quatermass, i.e shoestring astro EQ st4 port mod.

It really is as simple as the picutre suggests. Once connected PHD controls everything, no other programs needed, just the webcam driver running in the background when you fire up the webcam via PHD.

HTH

Stan

GUIDE SETUP.tif

Edited January 29, 2012 by stan26

[austen4]

Hello Stan,

I take it that most logitech webcams will work? Does PHD have a list or do they have to have certain requirements?

I think I am going to get the £80 USB one as my laptop is quite new.

That diagram is really useful. Bit off topic but its really quite accurate at how everything looks, well done .

Thanks

Edited January 29, 2012 by austen4