Thread: Centring Microscopes

Originally Posted by Stustoys

Hey you go BT,

The grey things are grub screws to hold the arbour/mirror holder in place. the depth of the mirror being adjusted by machining the face below...

Stuart

The machining to depth has me concerned. The mirror is affixed but could be covered during the turning but ensuring accurate realignment in the lathe of the arbor for turning could be tricky. And what happens if the mirror is too high? How about a finely threaded collar below the arbor flange for mirror height adjustment? Could well be whimsy on my behalf.

BT

Hi BT,
The corner will be under cut so radial runout shouldnt be an issue. The theory is that the tight fit between the arbor and the bore well mean axial runout wont be a problem.( would guess the axil runout would be much less anyway... but I dont recall ever testing that).

To high with the mirror is a good thing, just machine more off the face. To low? bin the arbor and start again or make a shim spacer

I'm thinking you'd need the same sort of thing with the mirror holder from the side but holding it for machine could be a little tricky.

As with most of these thing, the second one will be easy lol

The threaded collar might be doable, but I think you'd have to give up some Z to make it fit.

Going to have to have a think about how big the mirror needs to be.


Stuart

Heres what you need BT
Plus Stus cardboard and PVC pipe Marcel to Cannon adaptor.

Stuart

Those B and L Stereozoom scopes are a touch bulky. Half an hour of trawling through similar bulky looking stereo scopes and I found this restrained Zeiss delight. Sadly the seller wants too much for it. The one eyed Marcel does provide some additional dexterity over the stereos.

Just so happens I have a hand me down, my wife's Canon Ixus, the same as yours. Both Bruce and Michael G sent me some black plastic bar a while back. After a bit of fiddling with some PVC pipe fiitings and some cardboard I'll have a go at an adapter using that bar.

BT

Make an offer Bob, you never know your luck. Looks nice, does it mention focal length?

I started with machiable wax but didnt like the result(which as it turns out machines pretty well even if you are running the lathe backwards lol). I have some "engineering plastic" of some sort but the last job I used it on it didnt seem all that stable on size over time. So layers of cardboard and Aquadhere it is. I think you'll be using the camera on 3X all the time so it wont really matter which on the steps on the lense you fit the tube to.

I guess I should take a picture of something with better finish that the kitchen rule.
Just remember not to turn the camera off before removing the adaptor.(though the cannon just errors, which is a good thing)

Stuart

Originally Posted by Stustoys

Make an offer Bob, you never know your luck. Looks nice, does it mention focal length?

I started with machiable wax but didnt like the result(which as it turns out machines pretty well even if you are running the lathe backwards lol). I have some "engineering plastic" of some sort but the last job I used it on it didnt seem all that stable on size over time. So layers of cardboard and Aquadhere it is. I think you'll be using the camera on 3X all the time so it wont really matter which on the steps on the lense you fit the tube to.

I guess I should take a picture of something with better finish that the kitchen rule.
Just remember not to turn the camera off before removing the adaptor.(though the cannon just errors, which is a good thing)

Stuart

More info here Stu - Zeiss Stereo Microscope with Boom Stand | eBay

Wow its nice... but its not that nice.
Thanks

Stuart

Forget Carl, back to Marcel. Stu, I'm thinking now that your arbor ( or vertically ) mounted mirror is a better option than the mirror being mounted Isoma style. The latter squanders too much of the 92mm we have to play with. I've been scribbling on my drawing board trying to come up with a way of having an independent mirror mount that can be adjustable rather than it being integral with the arbor. The arbor could be hollow allowing a centring spigot to be machined on the mirror mount. I'll stop scribbling and draw what I'm trying to describe. BT ( still no functioning enter key on this keyboard, hence no punctuation ).

hi guys yesterday i saw some deckel fp1 optical peace's
i think they were for edge finding.
is that the sort of thing as a centering microscope.
aaron

Hi Aaron,

I think some centring scopes only have one line, so I guess you could call them edge finders?
But I wouldnt really know as I've not layed hands on a real one.

Where's that drawing BT? (I've had yet another idea..... how about bringing the "Isoma mount" in from the opposite side to the scope? One bore straight through, so at least those two have to be in line)

Stuart

Originally Posted by Stustoys

Hi Aaron,

I think some centring scopes only have one line, so I guess you could call them edge finders?
But I wouldnt really know as I've not layed hands on a real one.

Where's that drawing BT? (I've had yet another idea..... how about bringing the "Isoma mount" in from the opposite side to the scope? One bore straight through, so at least those two have to be in line)

Stuart

More scibbling at lunchtime today Stu.

I'm developing an idea for slight rotational adjustment of an Isoma-esque mount on the arbor centreline. Along the lines of notching the mount from both sides to form a rib and use opposing set screws acting against the rib to rotate and lock the mount. The tricky bit is axial adjustment. And an even trickier bit is how do we machine the end of the mirror mount at exactly 45 degrees?

BT

I'm not100% sure we arent talking about the same sort of adjustment
Given the small depth of field, I've been rethinking just how close we need to get. Infact i'm beginning to think you can use one error to correct another and it wont matter. Going to have to think a little more about that. The scope is sliding in a tube that is at a fixed angle to the mirror(assuming the nuffnuff machined the tube the right size). The focal length* is fixed. So the total error of the mirror angles is fixed reguardles of where in the tube the scope is........I think lol

Does epoxy stick to platinum?

Stuart

*different users may have different focal lengths so might need to adjust the scope if things were miles out.

Originally Posted by Stustoys

I'm not100% sure we arent talking about the same sort of adjustment
Given the small depth of field, I've been rethinking just how close we need to get. Infact i'm beginning to think you can use one error to correct another and it wont matter. Going to have to think a little more about that. The scope is sliding in a tube that is at a fixed angle to the mirror(assuming the nuffnuff machined the tube the right size). The focal length* is fixed. So the total error of the mirror angles is fixed reguardles of where in the tube the scope is........I think lol

Does epoxy stick to platinum?

Stuart

*different users may have different focal lengths so might need to adjust the scope if things were miles out.

I will try to knock up a legible drawing tomorrow then we will see if we are discussing the same thing.

The epoxy can be used to form a clamp. When I re-adhered the Isoma mirror I avoided placing Araldite on the mirror face. I built it up the mirror sides and just over the back along the edges.

BT

Rather than machine the angle exactly, how about making up a flap that is held back against a grub screw by a tension spring. To fine tune the angle, adjust the grubscrew. Loctite takes 24 hours to cure so you could assemble, adjust and then 24 hours later it should be fixed.

Michael