Printing the focusing assembly for flat-top microscope

Hi everyone.

I am trying to assemble the flat-top microscope and there is part of the focusing assembly that is hanging in the air. The printing of that doesn’t go very well. Any thoughts on how to do that?

Have you re-built the STL from the source OpenSCAD files, or is that the STL from the instructions?

The flat-top was a quick development some years ago, I think it uses the base Microscope code, but it will be base on an old version and it is likely that the scad will not work with a newer version of the Microscope code.

I did have a look at it a few weeks ago, there are built STLs that shoukd print. I shall try to find where they are.

I have used a snapshot from here

Looking at the STL in that artifact (from 2021) and the images in the instructions, the access hole for mounting the optics module has been moved.

The part that you have printed should work, as long as you are able to reach the optics module mounting screw through the access hole. The print problems are in a purely cosmetic part of the casing.

I think it is probably not worth fixing this issue itself, it should be relatively straightforward to adjust the separate_z_actuator from the current Microscope to be a replacement here. There are many small improvements in the z-axis since 2021. I should be able to look at that a bit next week.

What are you planning to use this for?

Thanks, that would be great.

I was planning to use the microscope for cell scratch tests. But mostly just to give it a try. I have decided to use flat-top one, because I use mostly cell flasks and well-plates in my work.

Looking more through the instructions, there is a photo on the final page OpenFlexure flat-top microscope which clearly shows this part shape and the result of the printing issue, https://rwb27.gitlab.io/openflexure-flat-top-microscope/images/optics_module_lock.jpg .

So it is not a problem introduced in later development, it is something that was there all along. It clearly does not give problems in use - we still use that prototype microscope.

It would still be a good idea if we can make a version based on the current v7.0.0 Microscope.

More of a mystery. The prototype that I have got is different in that position.

The sequence of parts and cuts leaves the motor mount arm in place, making everything have printable slopes.

Interesting. I’ll take a look later what kind of stl files are built from the scad files.

UPD:
built one is exactly the same as in artefacts

I had a roll back through the commits. The development of this version was at a time when the main microscope code was changing rapidly. My physical version seems to be based on the ‘initial commit’ of the flat-top (the top mounting points are closer together) but at an older or newer version of the main Microscope sub-module than is linked in that initial commit. As given in the initial commit, the focusing assembly does not build completely. When the Microscope sub-module was updated a few commits later, it has the other changes that cause the problem that you see.

The solution is to change line 64 of focusing_assembly.scad to have motor_lugs=true instead of false. Then it looks to be printable.

(If you use !false for true then it is a single character change)

@raiksv Here is another version of the focusing mechanism for the flat-top microscope, if you are still interested: Strobe-enhanced microscopy stage