PUMA open source FreeCAD microscope

[Dubious]

Came across an article about this open-source 3d-printed microscope, files available on GitHub. The PUMA (Portable Upgradeable Modular Affordable) scope starts with a 4x objective but it is configurable. Illumination is via a mirror. While the basic version is monocular, a trinocular version is also available.

https://hackaday.com/2021/09/09/highly- ... n-freecad/

For those who don't want to bother with 3d printing, the PUMA Foundation Scope can be purchased as a complete kit from a UK company:

https://www.optarc.co.uk/products/puma-products/

Instruction manual:
https://www.optarc.co.uk/wp-content/upl ... nScope.pdf

[tgss]

I haven't read through all the material yet, but the project looks very interesting and a lot of fun. Thanks for bringing this to everyone's attention.
Tom W.

[microcosmos]

It looks like a really interesting engineering project. I would be curious how well it can withstand actual field use (and how easily it can be repaired) e.g. in a tropical rainforest or caving expedition, with reasonable care (like storing in a waterproof shockproof Pelican case when not in use).

I noticed there is no nosepiece (or did I miss it somewhere in the user manual)? I think it would be nice to incorporate a small nosepiece for just two or three objectives for different observation modes or different magnifications, since it is not always possible to unscrew one objective and screw on another in the field when your hands are wet or muddy.

The nosepiece doesn't have to be tilted like on regular microscopes. It can be a horizontal rotating disc or maybe even just a slider.

[Scarodactyl]

Looks like a neat project. I might have a swing at it, though I don't know freecad so modifying parts might be more involved.

[MicroBob]

Hi, thank you for posting this!
I can see several uses for such an open source 3d printable microscope stand:
-availabe in places where shipping is expensive and used market small
-ideal basis for add ons
-common platform for courses and projects
-field microscope

I haven't read the full description so far, but to have an idea of the limits of this design: Does it have a condenser and an objective changer?

Bob

[Dubious]

The basic PUMA is a tube with eyepiece and 160mm objective (RMS and fully changeable) and a simple mirror for illumination. But according to the literature it can easily be expanded into a serious trinocular scope, and you can add just about every other bell and whistle known to microscopist:

"UPGRADEABLE and MODULAR: Like many professional series of laboratory microscopes, PUMA is modular. You can use it as a simple - but high quality - monocular microscope with an adjustable mirror for illumination (so not requiring any electronics at all) - all the way through to an all-singing, all-dancing trinocular scope with full Kohler illumination and an augmented reality unit for a heads up display of its integrated computer allowing for digital measurements and much more - while still being fully portable. Many other configurations are also possible e.g. epi-illuminated, fluorescence, dark ground, polarisation, etc. However, PUMA uses the concept of modularity to enhance its role as a standard benchtop observational microscope and to make it possible to upgrade without duplicating existing 3D printed parts and to switch modalities with the greatest ease and simplicity. No attempt has been made to make PUMA a general optical bench.
. . .
HIGH QUALITY ILLUMINATION: Full Kohler illumination with access to illuminated field and illuminating aperture stops is part of the PUMA standard together with an Abbe-type condenser unit. There are also simpler illumination schemes for those who do not need such high NA imaging. There are also epi-illumination, fluorescence illumination, dark ground and polarisation (both trans and epi) options as well as simple mirror-based illumination. Fourier-plane phase contrast is also possible by condenser aperture shaping (so without the need for special phase contrast objectives and tube phase rings). The illumination system was such a major component of the PUMA project that is was given its own development name - the 'Dominus Illumination System' (or just 'Dominus' for short)."

https://github.com/TadPath/PUMA (lots more information on this page)

PUMA has a Youtube channel with a half-dozen videos showing its construction and use:

https://www.youtube.com/channel/UCOvBah ... 5ycQEsgEnQ

[BramHuntingNematodes]

I am always like, "uh yeah I guess" with this but this looks much better than the last 3d print scope which as I recall involved printing this huge heap of plastic to serve where a conventional scope would have a big cast iron base

[Dubious]

I'm waiting for someone here who has a 3D printer to create a PUMA scope and report on how well it performs The PUMA is not going to challenge traditional (heavy) metal construction for stability and ease of use, but for a portable field microscope it has some very intriguing options. While I'm not yet sure what to make of some of the features such as the "augmented reality display," "digital spatial light modulator" and "Schlieren-based phase contrast," I probably just need to do more reading. The main Youtube video is forthright about the limitations of the PUMA, such as its light-weight construction making it susceptible to vibration, etc. It does not have an objective turret option, but changing objectives looks to be fairly fast.