Z-stage - differences between V1 and V7

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1

I’m trying to modify the microscope z-axis actuator to move an array of lenses. It looks like the z-axis described in the original 2016 paper is quite different from the current v7 design. Are the original openscad files still available? (The docubricks link from the paper: http://docubricks.com/projects/openflexure-microscope times out for me). And are the changes described anywhere? Thanks!!

2

That actuator (v5.16 had it v5.20 was already the new one, both release only seem to have a beta tag and I don’t know what .17-.19 were. Some of this predates me.) would have been back when we were on github in Richard’s own namespace. Docubricks was an experimental ope source documentation program, unfortunately everything for the docs are in an XML format so it is not easy to read the old docs.

Back then it was before we auto-generated STLs so those were in the repo (they were later pulled out of the history as the repo because too big to easily clone over a mobile connection in many countries). So they are in the source archive for the releases:

I would get STLs here:

And the OpenSCAD is here:

The changes are not described in too much detail anywhere that I can think of as this was many years ago when we were a smaller team. Basically the difference is twofold:

  • The new version mounts with a screw the other one was a friction fit that loosened over time with plastic creep and the objective would be at risk of dropping.
  • The new version is a 4-bar linkage with arms coming straight out from the actuator, the previous version was 2 connected 4 bar linkages that were much longer fixed to the corners of the inner walls. The old version was significantly less rigid than the new one.
3

Ah-ha, found the PR that did the change. Hard to isolate the actual code changes as all the STL changes are in that repo, and because we were less good at broken up small MRs

4

Thanks!! This is very useful. The 2019 scad code is actually easier to follow (at least for me - I’m no expert). And thanks for the detailed explanations in your previous reply. I really appreciate it.