Two spectroscopes,one telescope.

Design, construction, tuning of spectroscopes
Information and discussion about softwares (telescope remote, autoguiding, acquisition, spectral processing ...)
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Alun Halsey
Posts: 20
Joined: Fri Jan 19, 2018 10:53 am

Two spectroscopes,one telescope.

Post by Alun Halsey »

Hi

Here are a few photos showing my rig consisting of a C9.25 SCT and its payload of an Alpy 600 and Lhires III. To attach both spectroscopes together I have used a Baader flip mirror which is more than capable of bearing the weight of both instruments,the Lhires is equipped with the faceplate with the M42 threaded hole from Shelyak and the screw in adapter from the flip mirror has been bonded using Loctite.no fear of any slippage and grubb screws lock down to ensure everything is tight as well. Skywatcher focus motor has been attached to flip mirror so as to aid remote operation (apologise for the rubber bands,still awaiting toothed belt) The Alpy works at f/6 with the aid of a reducer and this results in having to refocus between instruments as to be expected and a shift of the target star due to different positions of the slits. Flexure wise,as I stated the flip mirror is more than capable and there is no movement in that regard :)

PCB board on the Lhires operates a focus motor attached to the collimation lens and another motor attached to grating micrometer and there is also a relay board in the well of the instrument which operates the calibration/flat lamp module,same goes for the Alpy,the black box attached to the calibration module contains a relay board and operates its calibration module. So as to block light getting into Lhires and protect electrics from damp I modified an old film changing bag which I cut and stitched so as to aid removal with instrument insitu.

Ioptron CEM60 carries the weight with no problems,everything is balanced to the point that if magnetic clutches are released the scope stays where it is pointed and on this mount that can be an hair pulling experience reaching that goal,hence the use of fender washers and the woodworkers clamp :)
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Alun
LHires III + SX Trius pro 694,ALPY 600 + SX Trius pro 825,Star analyser 100,C9.25,Esprit 150 ED Apo, Evostar 72ED with Sol'Ex SHG. Mesu 200 Mk1
Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

Re: Two spectroscopes,one telescope.

Post by Hamish Barker »

HI Alun,

That looks like a comprehensive and perhaps fully remote operated instrument suite!

How do you find your targets if they are faint? Do you use another camera and telescope (eg. a 50mm finder with camera) to platesolve? Or is the image in the alpy or LHires guide camera good enough to platesolve?

I use a flip mirror upstream of my L200 to send the light to a DSLR for platesolving. But I don't have an observatory, so that is a big help, as I then don't need to care about making a good two /three star alignment. My mount stays put in the yard and gets covered with a tarp when not in use, while the optical tube (f6 200mm newtonian) and permanently mounted spectrograph, flip mirror etc goes into the garage.

Cheers,
Hamish
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: Two spectroscopes,one telescope.

Post by Robin Leadbeater »

Thanks for the follow up photos Alun,

It confirms my suspicions that I really should upgrade from my EQ6 before going down that route ! Kudos for fully automating the LHIRES III too.

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
etienne bertrand
Posts: 1040
Joined: Mon Aug 31, 2015 11:26 am

Re: Two spectroscopes,one telescope.

Post by etienne bertrand »

Thanks for this report. You use Lhires with reducer on SCT ? Normally this spectrograph work at F/10 or minimum F/8 C. Buil say ?
Alun Halsey
Posts: 20
Joined: Fri Jan 19, 2018 10:53 am

Re: Two spectroscopes,one telescope.

Post by Alun Halsey »

Hi Hamish,

I polar align using Ioptron Ipolar (same as polemaster) and Sharpcap and I tend to stay on one side of the meridian (I mainly observe Be stars) and the goto on the CEM60 is pretty good enough
to put the target star on or near the slit,if I struggle to find a faint target I will slew and sync to a nearby bright star. Have tried plate solving again with Sharpcap whilst deep sky imaging and have found it to either take too long or totally fail,but that could possibly be more down to user error :oops: Apart from opening and closing the observatory roof everything else is remotely operated via Windows Remote Desktop and ethernet using the house electrical wiring.

Hi Robin,

Happy to help but I cannot take any credit for the automating of the Lhires,I got the info from you http://www.threehillsobservatory.co.uk/ ... opy_22.htm and from Paolo Berardi
http://quasar.teoth.it/html/USB_relay/USB_relays.htm so kudos to you guys :)

Regarding the EQ6,your C11 is around 27 lbs which is seven pounds more than my C9.25,I don't see there being any problem with the 6 carrying the weight as long as everything is well balanced.
I am more than happy to set the rig up on my EQ6 and run it for a while and get back to you,I need to test the mount as I have just finished adjusting the Rowan Astronomy Zero Backlash Worm
Mount.

Hi Etienne,

You are welcome,no the Lhires works at f/10 as it should,the reducer is attached between the calibration module of the Alpy and the flip mirror hence having to refocus between the two instruments.

Cheers
Alun
LHires III + SX Trius pro 694,ALPY 600 + SX Trius pro 825,Star analyser 100,C9.25,Esprit 150 ED Apo, Evostar 72ED with Sol'Ex SHG. Mesu 200 Mk1
Hamish Barker
Posts: 226
Joined: Thu Jun 20, 2019 12:11 am

Re: Two spectroscopes,one telescope.

Post by Hamish Barker »

Thanks for the response alun.

I guess you could add spacers and shims between the Lhires and flip mirror making it focus at the same (or nearly same) point as the alpy and its reduced optical path, reducing the amount of refocussing.

Cheers,
Hamish
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: Two spectroscopes,one telescope.

Post by Robin Leadbeater »

Alun Halsey wrote: I am more than happy to set the rig up on my EQ6 and run it for a while and get back to you
Hi Alun,

Don't do it just on my account. My EQ6 is on a tripod and does seem to flex quite a bit if it is windy. Another issue I would need to check is the clearance round the observatory walls. It is quite tight in there !
http://www.threehillsobservatory.co.uk/ ... b_2010.jpg
http://www.threehillsobservatory.co.uk/ ... l_2014.jpg

I have all the bits so could easily try it. I just need to get round to it. Although I cannot do it remotely It only takes a couple of minutes remove the LHIRES and replace it with the ALPY plus reducer which I have done on occasion during an observing run so I have not bothered so far.

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Alun Halsey
Posts: 20
Joined: Fri Jan 19, 2018 10:53 am

Re: Two spectroscopes,one telescope.

Post by Alun Halsey »

Hi Hamish,

Keeping the Lhires close to the flip mirror causes less strain on the connection to the scopes visual back,but if a suitable plate were to be machined and placed between the two,mirror casing and plate would have to be bonded together for added strength,then I suppose it could be done. The other option though is to do away with the reducer and then run the Alpy at f/10 :)

Hi Robin,

I wanted to replace the CEM60 with the EQ6 anyway as I wanted to try out the setup of the Rowan zero backlash module and since my setup is virtually modular it doesn't take long to swap out.
After setting it all up earlier today I found to much wobble is introduced by the Rowan module (floating worm affair) and no matter what adjustments I made this movement would not go away have now replaced the original worm housing,much more sturdier and the mount slews with all the weight of the C9.25 and the two spectroscopes without as much as a stutter :)

Cheers
Alun

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LHires III + SX Trius pro 694,ALPY 600 + SX Trius pro 825,Star analyser 100,C9.25,Esprit 150 ED Apo, Evostar 72ED with Sol'Ex SHG. Mesu 200 Mk1
Ken Harrison
Posts: 197
Joined: Thu Oct 25, 2012 5:45 am
Location: St Leonards, Australia
Contact:

Re: Two spectroscopes,one telescope.

Post by Ken Harrison »

Very impressive.
I, like Robin, and others use the C11 on a NEQ6 mount.
With Astroart, plate solving, image acquisition preprocessing and guiding the setup works well for me.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before....
"Imaging Sunlight - Using a digital Spectroheliograph" - Springer
http://www.astronomicalspectroscopy.com
Alun Halsey
Posts: 20
Joined: Fri Jan 19, 2018 10:53 am

Re: Two spectroscopes,one telescope.

Post by Alun Halsey »

Thank you Ken,I have a copy of Astroart 5 and use it mainly to control the Starlight Xpress cameras. Will have to look into the guiding and plate solving capabilities and hopefully
can drop PHD2.

Cheers
Alun
LHires III + SX Trius pro 694,ALPY 600 + SX Trius pro 825,Star analyser 100,C9.25,Esprit 150 ED Apo, Evostar 72ED with Sol'Ex SHG. Mesu 200 Mk1
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