C-mount - proprietary fit?

[Firebirdie]

Hi all,

My Motic microscope has 2 unremovable screws where one would expect to put a c-mount for a camera. I found an installation video that depicts a missing component (trinocular port). Has anyone seen this before? Is this component something I can buy or are there any workarounds, aside from mounting a camera on an eyepiece instead?

Please see the attached pictures, as they will explain it better.

Thanks for any help,

Kind regards
Firebirdie

[Scarodactyl]

You need the appropriate dovetail adapter for it, yeah. That's not too unusual. You can probably get a third party one, what is the internal diameter?

[Firebirdie]

Hi Scarodactyl,

Thanks for the lightning fast reply . The internal diameter seems to be 42mm. It would be great if I could buy a third party adapter somewhere, but I'm not sure how to search for it.

[Firebirdie]

To be more clear, this is the adapter that I have. I thought it would fit, but the two fixed screws prevent it.

[dtsh]

If I am understanding the images correctly, the two screws look like they could/should be backed out to allow centering the dovetail.
Looks to operate on the same principle as many condenser mounts and other parts where centering is needed.

Assuming there are no optics in the trinocular mount, it one could get the dimensions of one it should be easy enough to fabricate one.

[PeteM]

I'd agree that the two screws should be adjustable -- and removed if desired. You can likely use the adapter you already have.

It looks like three screws will remove the extension from the trinocular head, which will allow you to safely apply a penetrating oil such as "Kroil" and heat if they prove to be stubborn. Be sure that whatever drive they are (hex, flat screwdriver etc.) that you get one that fits exactly. With a bit of patience, solvent, and heat they should back out. Someone got them there in the first place.

It's possible that a bit of something like "Loctite" was applied - heat will also loosen that up.

[Scarodactyl]

That doesn't look like the right dovetail to me. Admittedly, the one I have is from a Martin Microscope adapter for the BA2, and i am not sure what model you have, but it has a 38mm outer diameter and an 8mm depth.

[Firebirdie]

Thank you for the replies.

I rechecked but there is no way to remove those two screws: there is a thread where they entered but there is no screw head (see attachment). I guess they were glued into place and then the head was drilled out, or something like that. There is a third screw that can be screwed in or out as desired to lock whatever is supposed to be in there.

Assuming there are no optics in the trinocular mount, it one could get the dimensions of one it should be easy enough to fabricate one.

Do you mean with 3D printing? Or did you have something else in mind?

It looks like three screws will remove the extension from the trinocular head, which...

Removing the trinocular part seems rather advanced to me. I wouldn't know where to begin to look for a good replacement, unfortunately, and I could break something internally.

That doesn't look like the right dovetail to me. Admittedly, the one I have is from a Martin Microscope adapter for the BA2, and i am not sure what model you have, but it has a 38mm outer diameter and an 8mm depth.

This is interesting. Is it also a 0.5x zoom adapter? I attached the specifications of the dovetail that I have, which shows it to be 42mm, which would ordinarily have fitted on the trinocular head. The fixed screws are approximately 5mm long.

A 38mm adapter could maybe fit in here and then be locked with the third screw that I can manipulate. I think this could be the way forward, if I can find an adapter like this. What do you think?

[Firebirdie]

38mm third party adapters like this seem to be readily available, if this is something that could work...

[patta]

Hei, from photo in post #8, maybe the two screws can indeed be turned with a tiny and long Allen key, like 2mm or 1/16" ? Try different sizes.
That is common with collimation grains.
You could also turn them with a plier, from the tip (protect the thread and the glass with some paper or rubber)

[Scarodactyl]

I may be leading you wrong with my measurements, which motic model do you have?

[dtsh]

Assuming there are no optics in the trinocular mount, it one could get the dimensions of one it should be easy enough to fabricate one.

Do you mean with 3D printing? Or did you have something else in mind?

3D printed, turned on a lathe, cut on a CNC mill, whatever gets a part that fits and is the correct dimensions. Hobby machinists are like microscopists, they're everywhere but can be hard to pick out of a crowd. There's a lot of overlap in curious nature as well; if you can take accurate measurements and provide a good description of what you need, there's a machinist out there (possibly relatively close to you) who'd be interested in helping. The internet is full of places they virtually congregate, much as here, just gotta find them and get them interested in your problem, much like here.

I am not a *good* machinist, but parts like this are relatively easy to make and they tend to 3D print well.

[Gasman]

Have to say I've 3d printed a few C-mount adaptors off Thingiverse and I thought my Ender3 V2 printer would struggle with the fine thread but they came out surprisingly well!

[PeteM]

Thank you for the replies.

I rechecked but there is no way to remove those two screws: there is a thread where they entered but there is no screw head (see attachment) . . .

The OEM had to have a way to screw them in. As Patta suggests, it's likely (from your picture) that it is a hex head drive and a hex key will work. Tiny "Vise Grip" pliers might also work them out from inside, about a third of a turn at a time.

Regardless of what adapter you have, get, or make - you'll want to be able to adjust those screws. I'd suggest finding a friend who is mechanically inclined and has a good selection of tools. Worst case, the screws can be drilled out (drill press, vise), the holes retapped, and new setscrews put in place.

[Firebirdie]

I feel like an idiot. Using a tiny hex key I was indeed able to unscrew them and put the adapter in. Thanks everyone for the help!