Phase contrast annulus, 3D printing

[patta]

Do somebody has experience with 3D printed, DIY phase contrast annulus for microscope?

I am working toward a 3D printed annulus that goes into the filter tray.
We want the annulus accurate and centerable; I try here to make it composed of two eccentric rings, rotating them the annulus can be centered.
I do not have a centerable condenser... all 3D printed/laser cut/ painted annulus that I have seen, are not centerable.

Here below the photo of current prototype. The file is on Thingiverse https://www.thingiverse.com/pattarini/designs

Please give me comment/suggestions!
I can modify it for different filter and annulus sizes. The current prototype is for Wild M11 microscope, 40 Ph objective.

[Macro_Cosmos]

A very simple method I can think of is having a large disk. Manually align the annuli by sliding it around and secure it with screws.
The exposed area can be blocked off with an appropriate circular arc cutout.
However given the size likely being a requirement, I don't think that will work out too well.

[elf]

I would have a hard time 3d printing those threads accurately with my FDM printer. An SLA printer would be a better choice. There are several available now for around $200US.

[patta]

A very simple method I can think of is having a large disk. Manually align the annuli by sliding it around and secure it with screws.
The exposed area can be blocked off with an appropriate circular arc cutout.
However given the size likely being a requirement, I don't think that will work out too well.

That is good idea, the issue is that with my trembling hands I won't be able to position i within 1/ 10 of mm. Ill try anyway.

I would have a hard time 3d printing those threads accurately with my FDM printer. An SLA printer would be a better choice. There are several available now for around $200US.

I'm actually going with FDM printer and normal PLA filament! No SLA available... The goal is to have something easy to print at home. The annulus itself is coming out quite well, while I have issues with the accuracy in the fitting and centering.

Annulus close up

[patta]

I temporarily stop the development of this thing.
Reasons are:
1) all prototypes I've made were unpractical to use, the filter tray is too wobbly and there is no much space
2) even when the annulus is centered, the condenser is not, thus the phase contrast doesn' work perfectly
Maybe will start again..

[Macro_Cosmos]

Wouldn't not centering the condenser simply cause illumination issues in the fringes of the image? Phase contrast should work even with slight misalignment regarding to the annulus. Centring everything does give the best results though.