Nano Converter plate incompatible with RPi 3b

Hey! I was building the microscope. Just finished printing the electronics drawer for RPi 3 Sangaboard 4 (electronics_drawer-pi3_sangav0.4) and the nano_converter_plate (which I found from the docs, but latest master build from git also is exactly the same). Just realized, The converter plate is designed for RPi 4 which has ethernet and USB ports in the reverse order of RPi 3.
RPi 4 is kind of expensive and I had Pi 3s lying around. Is there a Pi 3 compatible converter plate or any configuration in the build from source I am failing to see?

Btw I am printing everything on my Elegoo saturn 2 resin printer :stuck_out_tongue: I know its not what most use to print it, but I didn’t had an FDM printer. I use a resin mixture I made with really good bending and mechanical properties; the rest of the microscope works really great. But wasted a lot of resin on this plate :stuck_out_tongue:

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Hi @ashish_kumar_4, it would be really nice to know how you get on with a resin printed version. I have many questions on how well it prints as the design is optimised for printing without supports on a FDM printer and that may not transfer well over to resin printers!

Your question about the nano converter plate for a Pi 3B is being addressed but is not yet released. It is part of a larger change to some of the details of the microscope base and drawer, where mounting positions have had to shift a little to accommodate different motor driver options. This is still in development, but the latest test parts are in the merge request at where there is a fully built set of instructions, including the different nano converter plates, under the ‘view app’ button. The drawer and converter plate for the Pi 3B are in the ‘customisations and alternatives’ section. The new nano converter plate will not fit the V7.0.0-beta1 drawer and the new drawer will not fit the side screw position in the V7.0.0-beta1 base. You will need to print a matching new drawer to fit the new converter plate. You will also need to print a new base if you need to be able to attach the drawer by both mounting screws.
As a development branch this is not yet tested, and the parts are liable to continue to change. In this case the main development is finished, but we do need to check that there are no unintended changes before incorporating it into a released version.

Please do post a picture of your microscope when you have it working.

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Thanks for your quick reply and sharing the latest insights. Would try printing the new base, drawer and plate sometime later after v7 is fully done. For now, guess I would just leave the plate unattached physically to the drawer; it would require too much resin to print them again.

And sure would share my photos when its done. Just sourcing a nano and some soldering remains. Btw I realized it wasn’t optimized for resin printing but it actually kind of comes out really nicely when printed flat on the build platform, with some supports required for the stage. There were some regions forming suction cups for the FEP which I didn’t realize before printing, but even still it came out great at the first try. The only thing was, The standard and even the ABS-like resins are just not flexible enough to withstand bending for flexures. They are too brittle. So after some experimentation, came up with a mix of 60% standard (cuz cheap), 30% ABS like and 10% elastic (esun eresin elastic). Was able to fully assemble the actuators and test it out with Viton O rings as well (Thought it would break but didnt).
Cuz of the suction forces, some layer squishing resulted but its barely noticeable. I added some holes placed at non functioning parts to reduce that.
Also, I am building an upright version as well, and printed its main_body tilted at 45 degrees, this one came out pretty nicely as well. As its a upright one, Thinking of designing a 160mm tube for the optics for cheap 10x eyepieces instead of a camera. Do let me know if such a design is also already been worked upon though :stuck_out_tongue: I’m pretty new to OpenSCAD.
Btw here is the unfinished build


That is looking great. Thank you for the recipe it will be a help to others on the forum.

I have not seen that anyone has done a version for direct viewing with eyepieces. OpenSCAD does take a little getting used to as it is all text based.

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Adding an eyepiece to the upright version will start to sound a lot like the PUMA though I’m curious how it might compare in terms of stability. My gut feeling is that you’d probably want to mount the eyepiece statically, i.e. not on the moving part of the Z axis, because otherwise it won’t be very stiff or strong. The OpenFlexure Microscope was never really designed for eyepieces, I think it could probably be made to work OK, but making it properly ergonomic is quite tricky.

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Yeah, would try the eyepiece later. Right now, I have been working on making modularizing the condenser a bit, making it suitable for 8mm LED, and making the Lens Gripper removable so I can add a condenser annulus I designed into it for dark field microscopy, as I was having a hard time finding the adafruit LED grid, and didn’t wanted to work on porting the code for other modules (maybe would do later). The dark field actually works fine (I think), using a condenser lens of 7.4mm EFL from edmund.
I also added a linear polarizer film inside the optics module, between the objective and the tube lens, but without modifying the 3d design at all. I just placed a circular film in the space between. Then I added another polarizer into the condenser with the detachable lens gripper, and rotating it did make it work for polarizing microscopy. Could see imperfections in glass, debris etc, but didn’t work for the prepared slides I bought off amazon, idk why :confused: And IDK how to prepare slides with purely glass (sandwiching 2 glass slides is too thick for the objective, and cant find thinner glass big enough rn), as using plastic tape interferes with the polarization; I think the tape makes all of the light unpolarized kind of, causing everything to become white.
Would put all this on a separate topic on the forum