STM Physical Design Basics

I’ve been mulling over a simple physical design for the STM.

My primary design goals are ease of finding parts and ease of assembly.

The support structure is an outer support frame with a heavy inner platform suspended by rubber strips for vibration isolation.

The rough approach of the microscope will have a stepper motor driving the scanning head towards the sample.  I’d like to use gearing to reduce the distance driven per step, and I’ll be using a stepper motor driver capable of providing 16th steps (that’s 0.1125 degrees on a typical 1.8 degrees per step motor).

I’ll probably need help in designing the rough approach – any mechanical engineers out there? I have access to a laser cutter and a 3D printer for making gears.

basic physical design of the STM


2 Responses to “STM Physical Design Basics”

  1. Travis Deyle says:

    Have you thought about using the MakerBot as the basis (CNC, 3-axis steppers) for your STM? It would be cool to have a swap-out head that let’s you 3D print, then another for STM.

    • Sacha says:

      Hi Travis, I really like where you’re going with that idea (and it would let this project piggyback onto an already wildly popular project).
      However, the max X, Y, or Z movement I can get from the scanning head is ~50um, so any stage needs to be controllable to something less than 50um. A MakerBot’s minimum movement in X, Y, and Z is far larger than 50um.
      You could design a head that incorporates the rough approach too, to take advantage of the XYZ gantry of a makerbot, but you’d still need to figure out a way to isolate the whole rig from vibration.