Microscope Stage Positioner: MakerBeam Rebuild MVP

Over the course of half a decade (!), the 3D printed arm on the XYZ positioner I use with the stereo zoom microscope sagged:

Microscope Stage Positioner - PETG creep angle
Microscope Stage Positioner – PETG creep angle

It’s about what you’d expect from a plastic beam carrying a big lump of brass and steel:

Microscope Stage Positioner
Microscope Stage Positioner

The near side of that arm (the -Y end) drooped about 5 mm below than the side nearest the Z axis slide, so it was time for an update.

Having some MakerBeam ready to hand, this didn’t take long:

Microscope Stage Positioner - Makerbeam overview
Microscope Stage Positioner – Makerbeam overview

Protip: before dismantling a fitted slide, mark one end so you know how to put it back together. Bonus points for taking a picture:

Microscope Stage Positioner - slide marking
Microscope Stage Positioner – slide marking

Double bonus points for writing a blog post.

Rather than fight with the existing fine-pitch USA-ian screws, I drilled out their threaded holes:

Microscope Stage Positioner - Y slide drilling
Microscope Stage Positioner – Y slide drilling

And epoxied 3 mm brass inserts in their place:

Microscope Stage Positioner - Y slide M3 inserts
Microscope Stage Positioner – Y slide M3 inserts

Those holes match up with a pair of corner cubes normally appearing on the end of the beams:

Microscope Stage Positioner - BHCS mods for Makerbeam
Microscope Stage Positioner – BHCS mods for Makerbeam

It turns out M3 button head cap screws will slide into the beams if you file the slightest angle on opposite sides of the button, although a small bag of tiny tee nuts should arrive in a while.

Then a variety of brackets spliced everything together:

Microscope Stage Positioner - Makerbeam detail
Microscope Stage Positioner – Makerbeam detail

Although it looks strictly from industrial, it actually wasn’t much better than the plastic edition and, in fact, the beam supporting the XY slides sagged about the same 5 mm. The plastic upright post also contributed a bit of wobble.

It turns out that the extruded aluminum beams have plenty of longitudinal and torsional stiffness, but all those flat steel fittings don’t.

There’s a way to work with the beam strengths, rather than against them, but that’s a story for another day …

2 thoughts on “Microscope Stage Positioner: MakerBeam Rebuild MVP

  1. I’ve had to do some minor rebuilding of Julie’s Kitchenaid stand mixer. Photographs of the disassembly makes for a much less interesting reassembly process. Glad I thought of that beforehand.

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