Looking to guide my LX200 Classic

[DeadMan]

Hi All,

I have been looking into setting up my 8" LX200 Classic for guided DSLR astro photography, and need some advice on what I need and how to go about it.

I currently have an old ETX90 piggybacked on my classic and was hoping to use it for guiding. i.e

I also own a Phillips Toucam Pro 740k (un-modified) , not sure how useful it will be for this but hey ho!

Any suggestions appreciated!

[ollypenrice]

It isn't easy to get these to guide well. The guide speed is far too fast at 2x sidereal if I remember.

I would use an OAG myself because of mirror shift and the complication of balancing a fork mount dynamically. (The presence of a guidescope makes this harder.)

In order to get the balance as good as possible, which is vitally important, you need a system of sliding counterweights available from Telescope House or home made.

Olly

[DeadMan]

I have heard off axis guiders are a bit of a pain to use, but you are definitely right about the guiding, balance is a pain to get right and and I can see flexture will be my next problem.

I have tried exposures of up to 30 seconds with a Canon 400D at prime focus and they have worked quite well, my problems start when I go over 30 seconds which results in stars zig zagging in exposures of 5 minutes+ which I guess is down to either imperfect alignment and tracking errors.

Would you recommend using an auto-guider to keep the scope in check?

The LX200 has a CCD (guider port) but which auto guider to begin looking at has left me rather puzzled.

[Merlin66]

I use a ST80 with a QHY5 to guide my 12" Lx. It can guide a star image on a 25 micron slit ( I do spectroscopy) indefinately.

I balance the OTA in Dec with a collection of fixed weights, then balance the mount in RA by using jogging/ velcro wrist weights wrapped around the dec fork arm. Works 100%

[DeadMan]

Thank you that's great info! do you use PHD or another program to guide ? or does it plug directly into the CCD (guider port).

[Merlin66]

I connect the camera ST-4 port directly to the CCD port on the Lx.

Yes, I use PHD (and Al's reticle) for guiding; CdC for GOTO etc

[DeadMan]

I connect the camera ST-4 port directly to the CCD port on the Lx.

Yes, I use PHD (and Al's reticle) for guiding; CdC for GOTO etc

Does the CCD port on the LX200 classic accept a standard ST4 compatible cable or is the pinout different?

[Merlin66]

According to the manual, p 16 it's the standard ST-4 pinout.

[DeadMan]

According to the manual, p 16 it's the standard ST-4 pinout.

Thanks Merlin66, I was confused as I have read a few conflicting reports about the CCD port on the LX200 stating that pin 1 should not be connected as stated here: http://www.mapug-astronomy.net/ragreiner/lx200ports.html

I have now assembled together a standard ST4 cable with a QHY5 attached to my 8x50 finder to start out.

Do you use a standard cable with yours?

[Merlin66]

Hmmm

The MAPUG diagram matches the standard ST-4 arrangement.

http://www.store.shoestringastronomy.com/User_Manual_GPUSB.pdf

(1/2 down the page)

I don't use the 12" anymore, and can't remember making up a "special" guide cable.

[tollytastic1]

Hi DeadMan, I have no experience of this at all and this is my first post but you may find this link helpful Balancing a Piggybacked ST80

Tollytastic

[DeadMan]

Hmmm

The MAPUG diagram matches the standard ST-4 arrangement.

http://www.store.shoestringastronomy.com/User_Manual_GPUSB.pdf

(1/2 down the page)

I don't use the 12" anymore, and can't remember making up a "special" guide cable.

Well I guess I should test it out, just hope that one of the pins does not juice up the LX200

Thanks for taking a look

[DeadMan]

Hi DeadMan, I have no experience of this at all and this is my first post but you may find this link helpful Balancing a Piggybacked ST80

Tollytastic

Very interesting articule cheers!

This will be going back on once I have got it all up and running and it will require some balancing

[Merlin66]

The only thing which would happen is the guide wouldn't work.......

[DeadMan]

Fingers crossed it does

I am using PHD to guide and nebulosity to image.

QHY5 is using the ASCOM drivers with "mount" set to "on camera" seems to connect fine so just need some stars.

[DeadMan]

Tested and works perfectly, thanks for your help Merlin66

[Rols]

DeadMan,How much does that ST80 weigh and how does your gears seem to be handling it? i'm working towards the same setup as you with an LX12".

was hoping to see a thread with this setup.

[Merlin66]

The ST-80 weighs in at 1.8Kg.

I had this guide set-up with an ADM minirail system and electronic finder (135mm telelens/ATik16 on top of my 12" Lx200 - no issues.

[DeadMan]

No issues at all, although the 8" uses the sames gears as the 12" and is a lot lighter so can carry a lot more weight if required.

The balancing could still be improved though, as I have found pointing directly upwards pulls back slightly, so I think I will install the bottom rail with a beefier counter balance than the one shown in the photo.

[Rols]

I had a chat with the guys at Meade today and they suggested that the drives would be fine upto a WO-110 but probably better not to exceed it. i was quite shocked at the strength of the system, i obtained the Meade rail counter weight system off ABS last week at good money, i will continue to run my 90mm until i get the nod from FLO that the new WO110 APO R+P is available and see where i go from their, i'm waiting to see a review on the new Meade LX80-GEM as i like the idea of visual and AP work from one mount side by side, although reading up it would be hard pushed to beat the NEQ6Pro...anyhow not to run off topic thanks for the reply, its good to read about a setup thats near identical to my own for once.

[Merlin66]

The image is my 12" Lx200 classic with an ED80 mounted above, and a piggyback Canon DSLR. It can handle a LOT more.