The stage and focusing motion can feel rather slow when using low magnification optics - 10 or 20x objective or a Pi camera lens. The highest resolution lenses need small motion increments which is part of what sets the standard motion geometry of the Openflexure microscope.
@MilliRowland has done some testing of the microscope using gearing of 1:1 or 1:1.25 instead of the standard 2:1. The motors seem to be strong enough for this, there does not seem to be any issue with missed steps. It just moves 2 or 2.5 times further per step, so gets where you want it to be more quickly.
There are some issues with modified gear ratios fitting on the z-axis.
If you would like to try this out, STLs for the gears and an analysis of the motion is in an issue on the Gitlab repository (issue #231).
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What is faster than 1:1.25?..1:1.5. I made some and tested it.
In this test I compared taking 11 images at 1:1.25 and 1:1.5.
Test_0001 is 1:1.25 @ 2:46s
Test_0002 X axis with 1:1.5 and Y with 1:1.25 @ 2:45s
Test1-5 XandY: (both axis with 1:1.5): 2:24s
This saves 2s/image or a 13.3% reduction in scanning time per image!
Cool.
The changed gear ratios were tested on very early v7 development, before alpha. The limit on the gear ratio was from the size of motor gear that would fit between the motor mounting lugs.
With v7.0.0-beta5 the motor lugs changed to have M3 nut traps. Those changes also removed some ribs on the mounting lugs which gives a bit more space and allows this tweak to 1:1.5
It is not possible to get a ratio of 1:1.5 with the standard gear tooth parameters, there would not be an integer number of teeth on the gears.
Did you change the total number of teeth from 36? Or did you use 15:21 (1:1.4 ratio) or 14:22(1:1.57… ratio)?
It is 14 / 22; for 1.571x speed (14 teeth / 22 teeth), (Gemini helped me with the calculations and I modified the scad files). 
The smaller gear barely fits the hex bolt head. Because I like to break things I made them helical too. Not sure there is any benefit to it, but I read it may provide some more torque? They work fine so far.
Gears.stl (521.2 KB)
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