Hi, my delta stage is finally done and works. However, the movement in X and Y looks diagonal on the camera. Because of this, stitched images look odd:
Is this intended or is my stage bugged?
Is this intended or is my stage bugged?
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You must already have correctly set the stage to Delta Stage geometry in the software settings, or it would not be focusing properly.
Did you print the optics module from the cartrsian Microscope rather than the one from the Delta Stage? The modules are optically the same, and have the same mounting, but there is a 45 degree difference in camera rotation.
No, I am quite certain I printed the one from the delta stage, and that angle looks more like 30 degrees, not 45, so rather unlikely. I had a problem with a screw not being properly lubricated and the motor turning way slower and sometimes getting stuck. I thought that I had fixed that by now, perhaps it’s just more subtle now. I will have to investigate that. To get access to the screws: is there some trick to remove the o rings without cutting them? I had a hard time while trying to relubricate the screw.
Or could there be other causes?
One leg not moving properly would do strange things. If it did not move at all you would see that the motor was not moving, and there would only be two degrees of freedom in the motion, so scanning in two directions would not allow focusing, or focusing would only allow scanning on one direction.
The scan you have would need all three motors. If one is moving, but not moving correctly, I am surprised that it ends up so very regular. I cannot think of a reason 
.
I suppose if the motors A,B,C are wired up B,C,A Then the motion of the delta stage in z will be identical but x/y would be rotated by 120 degrees? I would guess the issue lies in which wire goes where on the Sangaboard.
Yup, the motors weren’t wired up correctly. I don’t use a Sangaboard but rather the drivers delivered with the motors. I tried to figure out to connect them from the Sangaboard schematics but it seems I have failed. I changed the wiring and recalibrated and now it works completely fine, aside from a minor misalignment:
But I assume that just comes with the 3d printed construction not being highly accurate and therefore isn’t fixable?
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I wouldn’t think that a 3D print would be that much out of square. It could be to do with the mounting wedge not seating/printing perfectly.
I tried around a bit, e.g. tightening the screw holding the objective and recalibrating a couple of times, but it is still slightly misaligned.
A thing I noticed is that when focusing it also moves very slightly in x and y, maybe that is connected?
But I am mostly fine with it, having to crop the scans a bit isn’t terrible.
The camera stage mapping calibration does measure x-y cross motion, but that information is not used in scanning. The size of staircase in the image edge that you are seeing is common on scans taken on the cartesian Microscope. I have not seen as many scans from the Delta Stage to know how they compare.