Motorised Focuser

[iceman]

Hey guys.

On the weekend I finally got around to installing the motorised focuser that Laurie (RAJAH) kindly made for me (thanks Loz!).

My dad was visiting for the weekend, so I took advantage of his engineering and DIY expertise to help me fit the motor to the scope.

The bracket is made from a piece of termite capping (galvanised steel), as that's all we could find at the hardware store :) The bracket fits onto 2 existing holes of the moonlite base, so no extra drilling into the OTA was required. A slot was cut out of the steel for the servo motor and screwed in place. The controller box with the variable speed knob, on/off switch and focus in/out control is simply velcroed to the OTA.

The only thing I haven't done yet is Laurie's "belt keeper" idea, to ensure the O-ring isn't lost on the ground should it fall off.

The O-ring connects the servo motor to the fine focus knob of my CR2, and turns it ever so smoothly. Meaning I don't have to touch the focus knob at high powers and there'll be no image shaking and shifting. This will be especially helpful for imaging.

It works, though I haven't given it a first light yet thanks to clouds.

Here's some pics from a few different angles.

http://www.iceinspace.com.au/images/accessories/motorfocuser/motorfocuser1.jpg

http://www.iceinspace.com.au/images/accessories/motorfocuser/motorfocuser2.jpg

http://www.iceinspace.com.au/images/accessories/motorfocuser/motorfocuser3.jpg

http://www.iceinspace.com.au/images/accessories/motorfocuser/motorfocuser4.jpg

Will report back once it's had first light!

[slice of heaven]

Thats pretty cool Ice.

The IIS sparky is pretty handy hey

[ving]

well "Loz" sent me one too... works great btw laurie!
didnt take any pics tho.
I didnt want to drill any hole in my OTA or anything so i attached it to the botom of my focuser...
the bracket I made out of an old PC case.

I had a chance to use it for the first time last night with my el-cheapo web cam on the moon and its smooth as!
NO MORE SHAKING!!!!
:D

you the funny thing about the motorised focuser........ nah I wont go there.

fangs Laurie :)

[iceman]

Where are the pics vingmeister?

Of both the focuser AND the moon shot?? huh let's see 'em!

ving where did you find a suitable O-ring? How big is yours?

[h0ughy]

great job. You should patent the pink hairband idea:whistle:

does the band wander over the knurled part and slip off?

[iceman]

heh, Eliza's pink hairband was my O-ring before I got a proper one :D How it's positioned over the finder is my "belt keeper" for now :P

No, the band doesn't move. There's a groove between the textured part of the knob and the smooth part, and the band sits nicely in there and behaves itself.

[ving]

my o-ring is not as big as yours :ashamed:

there is only about a 2cm gap between focuser knob and motor spinny thing (sorry bout the technical term) so a small thick lo-stretch o-ring did wonders.

the battery in my laptop needs replacing. as I was setting up for a shot the battery went phut on me. :(

my webcam is actually one of those really old dolphin digicam/webcam jobs with the lens taken out...

is there a way of getting a wider FOV with a webcam?

[slice of heaven]

What focuser have you got Ving?
Wondering how they work with the gs focusers.

[ving]

I have a 2" gs focuser slice...

you want one? talk to Laurie now! :D

[slice of heaven]

I might have to Ving.
Poor Laurie wont get a chance to do any viewing.

[ving]

I'll get some pics posted soonish showing my bodgey job :)

its not very neat, but its functional. I could and probably will end up doing a much neater job of it but this will do for now. :)

[atalas]

Yes very nice job I must say,green and gold too Australian made.


Louie:)

[iceman]

haha yeh I thought I had some black electrical tape but couldn't find it :cry:

:D

[RAJAH235]

Hiya all, Thanks for the kind words, Mike & David. I thought you might like them. As you said, there's no shake now at high mags. + you can get the focus spot on.
The 'O' rings/drive belts are available from any Bearing supply Co. Cheaper by the 10 pack.
Mike, that installation looks great. Nice to have an engineer around at times. David, where are your pics? :)
Glad to be of help. Regards, L. :D

[iceman]

Thanks Loz, i'll try and find some better O-rings this weekend.

[ving]

er... the pic?

they are over there!---->

*hides*

[ving]

here yas go... like I said, not tidy but still functional.
click thubnail for larger pic.

http://photobucket.com/albums/v46/ving68/8inch_dob/th_3.jpg (http://img.photobucket.com/albums/v46/ving68/8inch_dob/3.jpg)
http://photobucket.com/albums/v46/ving68/8inch_dob/th_2.jpg (http://img.photobucket.com/albums/v46/ving68/8inch_dob/2.jpg)
http://photobucket.com/albums/v46/ving68/8inch_dob/th_1.jpg (http://img.photobucket.com/albums/v46/ving68/8inch_dob/1.jpg)
:)

[iceman]

Good work David! How do you find it, in practise?

[ving]

I havent had much chance to view yet mike. last night I took the laptop out with the webcam and mucked around with the moon. focusing was great with no wobbles. then I tried some viewing with the webcam barlowed... smooth.

umm... mike, I dont seem to have settings such as "gain" on my k3ccd....
and why is it that when i viewed jupiter it was just a big blob surrounded by 4 small blobs... (ei no detail at all on the surface of the planet)?

[slice of heaven]

How 'fine' is the focusing Ving?

BTW I like your method of posting the thumbnails, easy to see the overall pic and the enlargement gives good detail.Nice one

[[1ponders]]

ving you'll find the settings on the menu under "video capture --> vidio source or video format", I think. (Don't have the program with me at the moment). Or download the program WcCtrl which allows you to adjust all your settings outside of K3 and then save them if they work well for a late imaging session. For example you can save your fav settings for the moon at different stages, Jupiter, Saturn etc (up to six different configurations)

[ving]

I thought i looked there... I'll look agian.
thnx paul

[ving]

the motor has a speed controller on it slice. seems infinitely variable between stop and full speed.

[iceman]

Probably because you're using an old webcam with little in the way of adjustable capture settings.
In k3ccd when you click the "video settings", it uses the camera's driver dialog. So your camera probably doesn't have a way to adjust gain, framerate etc.. what settings are available to you to adjust?

That's because it's overexposed - because you probably can't change the shutter speed with your webcam settings.

I had exactly the same problems, when I first started and I was using an old (5 yrs old) intel create & share webcam. I could not adjust many settings and jupiter appeared as blob with small blobs, and Saturn was just a oval blob.

http://www.iceinspace.com.au/images/images/planets/webcam_saturn.jpg

http://www.iceinspace.com.au/images/images/planets/20041201-jupiter+moons.jpg

Without the ability to change settings or shutter speed, the ONLY way I found to get some sort of an image was to use an aperture mask and cut down the scope to like 2 or 3 inches, so less light was coming in and the webcam wasn't overexposing the image.

That changed instantly when I got the ToUcam, because it has the settings to control shutter speed and gain.

[ving]

you are absolutely right mike :)
its a really old cam.
I'll try an aperture mask next time i am out...
thnx :)

[iceman]

My hartmann mask has 3 holes, about 2 inches wide each, and I had to even cover 1 or 2 of those to stop the webcam overexposing the image..

So you may as well try with your 60mm wobbletronic, you'll get just as good results :D

I think you need to buy a ToUcam :poke: :D

[ving]

hmm... i'll need to run that by mission control. I dont like my chances tho...