Morgan resolution

I was asked this question again, and this was my reply:

Disclaimer: The calculations were done quickly on a calculator and may have slight rounding errors – but not to a factor of 10!

The large wheel radius is 75mm making circumference = 471mm
The pulley on the motor is typically T2 20 or T2 16: 40mm or 32mm

Ratio is thus 11.78 or 14.72

Given a step size of 0.9deg, and 32uStep an electronic step is 0.028125 degree
With the ratio, that becomes 0,002387521 or 0,001910666 degrees on the large wheel.

Lowest possible resolution would be at full arm extension 90degrees to the extended direction, which is less than 150mm+150mm from the SCARA tower, but for simplicity let’s make it 300mm.

Circumference of that symbolic circle would be  1885mm, making the single step lowest resolution movement 6.282mm*0,002387521 (40mm pulley) which is 0.015mm.  This is smaller than the effect of filament variation or room temperature variation on your print… 

Morgan Pro has a advertised specification of 100micron resolution – which means it will definitely pass the specification and will probably achieve more by a factor of 9 or 10 in terms of movement alone

With the smaller pulley this is even higher….

Enough calculations for now 😉

3 thoughts on “Morgan resolution”

  1. Amazing! Looking videos leads me to a another range-of-motion question: what is the full angular range of motion traversed by the drive wheels? 90 degrees? More?

    1. The range of movement is a bit more than 90 degrees if you use the full bed size of the new Morgan Pro 380×220: semi circle.

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