I need a 2"-->1.25" adapter, but "sunk" into focuser?

[erick]

Just thinking ahead. I couldn't get enough in-travel on my standard Bintel Crayford 2" focuser for my webcam (Logitech Quickcam Pro 4000) mounted on an adapter (photos attached - apologies out of focus). The adpater is screwed up tight - I don't think there is a way to get the adapter further into the webcam - there are two options where it is coming to a halt - the thread or the inner flange against the "screw in" tube in the webcam. The external flange sits about a mm off the webcam body.

I've more testing to do in daylight, when the rain stops and when I have time, but am thinking of options now.

One is to "butcher" the adapter by removing the flange that stops the adapter going deeper into the 2"-->1.25" adapter I use in the focuser (std with the focuser - see photo), but I'd prefer not to. The webcam focuses in the barlow and the flange obviously locates the camera in the same position relative to the barlow/focuser (within all the sloppy tolerances) each time, so I'd rather keep it.

I've searched the net and the forum for the second option which I really want, but cannot find it. To describe:- The 2"-->1.25" adapter stands the webcam some 10mm above the focuser. If I could get a lower profile adapter? But, even better, can I make up a 2"--1.25" adapter that will sit in the top of the focuser. I'm thinking of an adapter with a 1.25" hole which is a snug fit for my webcam adapter, that sits under the upper lip of the focuser (maybe with a couple of hooks up over the edge to stop the whole lot falling onto the secondary in the tube!) and at the right depth so the webcam is right up to where it almost touches the top of the focuser, yet the adapter is still held tight by the screw/brass ring at the top of the focuser. I will have gained more than a cm of in-travel.

Does such an adapter exist for sale, or has anyone made one and can share experience?

Many thanks in advance - Eric :)

[ballaratdragons]

Eric, I have a 'sunken' 2" to 1.25" adaptor you are welcome to use.
It drops the internal stop to 18mm below the standard Crayford Focuser. :)

I just hope the Camera Ball doesn't stop it from going in that far.

[Dennis]

Try Scopestuff (http://www.scopestuff.com/ss_npea.htm)- they have a Negative Profile Eyepiece Adapter, 1.25" to 2". Cost US $39.

Cheers

Dennis

From their website:
"Need more in-focus when using a 1.25" eyepiece or accessory in a 2"
focuser? Our Negative Profile Eyepiece Adapter allows the eyepiece
to be inset over 3/4" more than a low profile adapter. The inset accepts
eyepiece bodies or accessories up to 1.75" in diameter. The eyepiece
barrel is held securely in the adapter with two rounded tip setscrews.

2" barrel is 1.6" deep and has a top flange. Interior diameter is 1.75".
Overall height is 1.75". Black anodized machined aluminum, with two
stainless steel rounded tip setscrews. Weighs 4 oz. Allen wrench
included."

[OneOfOne]

Problem is, if you order from them you will never get it.

Have you looked at some of the "usual" Aussie sites? I think I have seen something like this before. Fortunately, if I needed one I would just make one up on the lathe...some boys have bigger toys ;)

[Dennis]

Are you confusing Scopestuff with Scopetronix?

I have always had excellent service and response from Jim Henson and his people at Scopestuff.

Cheers

Dennis

[tnbk00]

Ive ordered from scopestuff and the service was awesome.....

[gbeal]

Me too, a great place to buy from. I have heard via a few forums that Scopetronix are difficult to deal with though.

[erick]

Many thanks everyone! Obviously I just couldn't search properly! :doh:

Ken, I'd be grateful if I can test your adapter on my next visit to SV. I can always withdraw the webcam and its adapter to ensure the webcam ball clears. :)

[bojan]

Erick,
I would "butcher" it, but then I would add the ring (with screw to fix it) instead of flange. Actually, I am just in a process of adapting one such adapter for myself :-)
If you wish, I can try to organize this for you as well..
When I am finished I will post the pic so you can decide if this is for you or not.

[iceman]

Get a ToUcam 900nc with an adapter :) It will come to prime focus no problems!

[erick]

Spend more money??? !!!!! I've give you my wife's number - good luck!

[erick]

Yes, I look forward to seeing your result. If I cut the flange off, the body of the adapter will disappear into the mount - no room for a ring :(

However, a bit more intelligent work in daylight with my existing bits and pieces might be all I need to do. Some months ago, I did get to focus using Ken's webcam adapter, so it must be possible - I'll pull the webcam body off and see where I can get the camera closer to the focuser. :)

[bojan]

Erick
When I was playing with my Quickcam, in order to achieve focus I un-soldered the CCD chip (it was TC255 in DIL8 package), then I mounted the socket instead. By inserting one or two sockets more I was able to move the CCD up (or closer to adapter) to enable focusing. This modification is also giving me the necessary space to insert peltier cooler...
Anyway, I will show you the result of this when I am finished.... I am doing this to attach Philips TouCam, which will be modified one rainy day in the near future :-)

[OneOfOne]

:doh:

Oops! Yes, I am getting confused. I have actually enquired several times about things from Scopestuff and found Jim very responsive, in fact a couple of times I have managed to get him before he has gone home and received an answer within minutes of posting an email. Sorry for the confusion.

Wish I had a famous name like his!

[erick]

Hi Bojan, how is this project going? Thanks, Eric

[peter_4059]

Erick,

Did you get this sorted - I had a similar problem and solved it by getting the flange machined off a 2" 1 1/4" adaptor. I can send a pic if you are interested.

[oggie doggie]

Peter, I would be interested in seeing a pic. I am having a similar problem and am not sure which is the best solution at this stage.

[bojan]

Not progressing much I am afraid... :ashamed:
Actually the reason is my new 400D... taking all my time :P

But I will try to post the pics of progress with QC so far tonight, if you are still interested :-)

[peter_4059]

Here's what I did to get more inward travel - purchased new 2" -> 1 1/4" adaptor ($25). Got old one turned down to remove the flange. Replaced the thumbscrew with a grub screw. Before and after in the pics below...

[erick]

Thanks Peter, for the pics.

I was able to reduce some length off the adapter and some of the threaded tube in the webcam which brought the CCD another 2mm closer to the focusser. I have had one test and it seemed that I was achieving focus now. Snake Valley starcamp will be my first opportunity to test further and, hopefully, try to capture some images.

Eric

[bojan]

Hi Erick, this is what I have done so far with QuickCam...
You can see how CCD is put forward, closer to the scope.
The cooling is not there yet, but now there is enough space for cold finger and peltier, this will happen one day....
All the parts are from Bunnings (plastic glands for cables), except 1 1/4" barrel, this was machined all the way to 1 1/4' and plastic nut was glued inside.
The same thing I plan to do with my TouCam.
If you are still interested, I believe I can organize the machining for you this weekend.

[erick]

Bojan, I think I'm probably OK, thanks, with what I have done so far. But I like the idea of lifting the CCD chip on several sockets, if I'm still not in focus. I'll have a look at mine and see if that is possible to do while retaining the threaded tube. Unsoldering might be a bit delicate?

[bojan]

Yes it could... I can help you with this.