Multi lens Astro GOTO camera

[DIYASTRO]

Its not looking good for a star test on the guidescope camera so have begun to assess what work is going to be needed for the 2 stage filter wheel / focus and camera rotation.

Taken a few pics to show where I'm at!

Some may recognise this from a couple of years ago when I began making it. It has had a few moddifications since then. The pics as follows.

Pic 1 Looking on top of the mount at the filter wheel section with my modded 350d attached.

Pic 2 As above but with a yes yes modded x/y webcam mounted. (Again, some may remember this posted in yes yes thread p8 Nov 2011!!!!)

Pic 3 Side view of the filter wheel housing showing the two gearbox drives, one on left for focus (Using the leadscrew method) the other is for the camera rotation gearing mechanism.

Pic 4 Side view of whole camera which shows the gearbox / stepper motor drives for the belt driven filter wheels. Also the right angled mirror assembly by which the camera obtains image from main lens.

Pic 5 This is the filter wheels exposed by removal of top section which is held currently by several allen head set screws. One wheel has the blue green red yellow filters with the 5th hole blank. The other wheel will have the 'exotic' Ha, Hb Oiii etc with again a blank space. This allows for both filter wheels to be alligned leaving a clear unobstructed light path. the wheels as said are driven via a stepper motor / gearbox from a circuit which can be proggramed and index's quite accurately each filter. Limit switches are also used to 'register' the advance of either wheel and counted / displayed on control panel so as to know which filters are in play.

Pic 6,7&8 are close ups of the gears for camera revolve and focus. You can clearly see the belt drive leadscrew focus system and it has remarkable accuracy when micro stepped.

So... Things that need attention are. The two drive motors that I 'exchanged' from stepper motor to dc need to be replaced. Unfortunately they have live caseings so when one motor is enigised the other wants to begin doing something! Back to stepper motors or perhaps a better choise of 12v dc motors.

The three drive pins from the 288t 48DP gear for the camera rotation need to be fitted.

A better system of attaching the top to the lower filter section for quicker filter change / 'borrowing' filters for other scopes!

The 25pin D skt on the top of the filter wheel section needs replacing so that the plug doesnt stick up in the air when connected. Lastly, a bit of tidy up on the electronic control panels. So plenty to do!!!

[Colin H]

Hiya Boyd

Looks amazing!  Just think what you could acieve if you had my old friend Ken W's workshop! 

Are your frame-grabbers able to work with NTSC cameras? 

Col.

[DIYASTRO]

Hi Colin!!!!

Great to see you on the SGL boards!

Thanks for kind coments, Not quite up to your Vinten standard but it works!

If Ken was still with us he would have fitted gyro blades to it by now or at least strapped it to 'little nell'! I would give anything (almost) for his workshops!

I think some of my frame grabbers work with NTSC never tried. I use Pal mode at present, although some of my cams have both scanning modes.

(eg Sony effio super HAD CCD II sensor).

Boyd

[Gina]

Fantastic

[earth titan]

Now thats proper engineering....

As a toolmaker by training, I can appreciate the work that's gone into that.

Nicely done.

[DIYASTRO]

Just to say thankyou to Gina and Tom for support!

Interesting Tom about toolmaking, that was my trade many many years ago when industry required people who could make things from raw materials and sell them for a profit! How times change.

A few pics to show that I have been doing something!

Pic 1  Eventually got some tape for labeling and hence marked up the  control unit so I dont get confused as to what switch does what!

Pic 2  Exchanged the 12v dc motors for the original stepper motors, this will give a far more accurate indexing for the focus and camera rotate mechanisms anyway. I changed them simply through cost, it was less expensive to run 12v dc motors than the steppers but that gave problems as mentioned in one of my other posts.

Pic 3-6 This is the result of stripping down the original guidescope module and left with a number of 'surplus' bits!

I have used the x/y mechanisms to make a manual indexable camera, it moves about 40mm in both directions.

I have used one of my Sony Effio camera boards which of course is a video cam.

Thought I would have a go at making some circuit by which I can 'switch' the camera from std. video output to 'digital'. (ie through a video converter) Obviously not finished yet but tested the circuits and it works!

I have simply used a small 6v relay to do the switch from video output which comes through the normally closed contacts and when the relay is energised it sends the signal through the normally open contacts to the video converter (frame grabber). This allows me to use the camera to a std video monitor or through the PC.

Some may spot an SD card reader which is pluged into the 4 way usb hub, I havent tried this bit yet but was thinking of possibly recording the images to the SD card, or have other images on the card e.g. 'star map' for comparison of what I am viewing. Strange idea I know but interesting. ( may be of interest to the video astronomy followers!)

The camera has a 58mm f1.4 lens on at the moment but that unscrews for the 2" scope adaptor for use on the scope.

Will post up progress .

Boyd

[DIYASTRO]

Thanks for your 'likes post' Gina.

I am going to redo the relay switching system on this camera. I think i will go for an opto isolater circuit to do the switch / flip from anologe to digital since having a relay powered up for some time simply eats power from already stretched supply!

Not too sure how the card reader will work out? the idea of course was to record images to card for use later in registax / photoshop or other. but..the idea of having a video image on seperate  screen which can be used for 'composure/focus' and also having an image from a card within the camera of a 'copy' of what you want to record displayed on the capture PC may have some merit. Will experiment!

Been working on the ideas for the control panel/console... lots of cables and connections required since I want most of the camera to be controled via simple switching / control circuits and not all through PC.

Boyd

[DIYASTRO]

Taking a break away from the soldering iron!

Been quite busy with building up some of the control gear needed for the camera.

The cables for conenction to the camera will come into the rear plate and plug into the skt's on the plates pictured in pic 1.

So

Pic 1  The two rectangular plates are the 'cutouts' for various connections at rear of camera. The plate bott.left is a conection plate which fits onto the focus wheel housing, and gives connections for various cameras eg. Canon eos, webcams / video etc.

Pic 2  Finaly wired up the two stepper motors on filter wheel for focus and camera rotate.

Pic 3  a start on some of the 'looms' which fit inside the camera and plug into the various modules. I have made them so everything can be unpluged either end to allow removal of each module as required.

Pic 4  Some of the control circuits including PWM, timers / camera triggers Joystick switching for various functions on the seperate modules etc etc.

Think I shall do some cut outs this afternoon... dont know how many soldered connections I have done in the last week or so but need to do something else for a bit!

Boyd

[DIYASTRO]

Have been continuing with some of the electronic connections and circuits... but also begun the connection boards / cutouts to hold the connections from camera /mount to control boards.

Thought I would post a couple of pics before the rear plate of the camera is replaced since the open view shows some other detail.

Pic 1 This is the rear of the camera with the rear plate removed.

It shows the camera module that is for the last set of optics, this is again an SPC900NC yes yes LX modded camera with a built in filter wheel for 6 x 1.25" filters. I will post more pics and info on this when the module comes out for its final 'tweeks'. This pic does show the 50:1 servo driven belt drive though and the 'triangular' shaped bit of aluminium in centre / rear is part of the counterbalence rails.

Pic 2 These are the cut out panels for the plugs / skts etc for the camera to communicate with the control gear.

Since there is a lot of things going on inside the camera with its seperate modules need quite a few connections to seperately operate it all. (have expained before why I have opted for more anologue control over total pc derived systems) This is the bit that I find tedious, drilling filling etc. 25 pin D cutouts are a pain, I know you can get a punch/die but the cost is very high!

Pic 3 This is the rear plate of the camera with the access cutouts to accept the connection plates.

Now the long haul of wireing it all up and finishing the cable looms for the modules.

Will post progress as and when

Boyd

[DIYASTRO]

Found a little time this morning to refit the guidescope module back into the main frame.

Also begun to fit up the conection boards at the rear of the camera for all the cables to control the various modules.

Pic 1 Rear plate with the two conection boards in situ.

Pic 2 Top of camera showing the filter wheel / primary scope camera conections. This enables the Canon dslr / SPC900NC LX or other / video camera to be connected with short leads, this plate has leads going to one of the connection plates at rear. So.. it has video, 12v dc power skt, programable timer conection, usb and RJ45 connection ability.

Pic 3 Side view of camera showing the rear conection plates which are fixed with standoff bolts to allow the cable connection plugs space to fit under the fork arm when in vertical position.

Pic 4 side view of the rear of the camera showing stand off connection plates. When the camera is eventually 'sleeved' /'shrouded' the stand offs will allow air flow in /out for the various cooling fans for the camera modules.

Not sure I will get much time this weekend to do much else to the build, its my sons birthday today and having party at home!!! But will post up progress as and when.

Boyd

[Gina]

WOW!  That IS complicated!

[blinky]

I have seen it 'in the flesh' so to speak - it's an amazing looking piece of kit!!! 

[DIYASTRO]

Its been quite a while since I posted in this thread, but have been working on the substance of it on and off over the past year.

I have started another thread on 'SCT modification/filter wheel and camera rotation' in this forum and at some point this camera thread will have links to a further one which I intend to call 'SCT Mod II.' This will tackle the modifications that I have done to the mount.

The control console for the larger first built multi camera is built tested and functioning well, will take pics of this when I have dusted it! ( been lying around for a while and wont let anyone near it!)

The pics I am posting just now are the slightly smaller multi camera, which although similar in design to 'big brother' has a few features which are different.

You will see from the 4th pic that the lens config on this multi rig is as follows.

Top left.........500mm f8 mirror lens......camera SPC900NC L/X

Lower left ......135mm f2.5 Pentax Tak.....camera SPC900NC L/X

Centre...........Watec 902H................Acting as finder scope

Top right........80mm F/l 325 f4...........camera SPC900NC L/X Sony ICX098BL B&W sensor with manual X/Y facility

This is the guidescope.

Lower right......80mm F/l 325 f4...........camera Phil Dyer Astro Video

(Modification)

All the cameras therefore can be remotely focused using the geared helical focus which house the various camera boards.

The first pic shows the first Dec (and RA) drive mod that I did using motor gear from EQ6. I have since done two fork mount mods to full goto which is what will be the essence of proposed new SCT Pt. ii thread.

Will post up the control consoles eventually with some pics.

Boyd