Thoughts on the next iteration of the Maslow 4

Technical Details
65

I realized I could use the sketch function in Ondsel/FreeCAD to prove that belt lengths being correct should inherently keep orientation correct.

I have constraints to keep the carriage 100x100 square and to keep that datum in its center. I have parameters for setting the XY offset of the center datum from 0,0 (bottom left of large rectangle). The rectangle is locked in place, and the lines for each belt have their endpoints locked to their respective corners of each shape.

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No matter what I set the center point to, this math updates the constraints (length) on each “belt” automatically and keeps the carriage oriented square with the frame.

The carriage is not constrained to prevent rotation. If I remove the calculated restraints on the belts, moving the centerpoint immediately rotates the carriage.

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So, in relation to the diagram from the plotter example I shared previously, this is the math for each belt:

D1
sqrt((xOffset + carriageCenterX - sledWidth) ^ 2 + (YMS - yOffset - carriageCenterY - sledHeight) ^ 2 + zOffset ^ 2)

D2
sqrt((XMS - xOffset - carriageCenterX - sledWidth) ^ 2 + (YMS - yOffset - carriageCenterY - sledHeight) ^ 2 + zOffset ^ 2)

D3
sqrt((xOffset + carriageCenterX - sledWidth) ^ 2 + (yOffset + carriageCenterY - sledHeight) ^ 2 + zOffset ^ 2)

D4
sqrt((XMS - xOffset - carriageCenterX - sledWidth) ^ 2 + (yOffset + carriageCenterY - sledHeight) ^ 2 + zOffset ^ 2)

x/y/zOffset values can be assumed to be 0
sledHeight/Width values are the offsets from carriage center to each belt measurement location, in this example they are half the true height/width of the carriage, respectively

Someone capable of testing their own firmware forks could probably implement test this on an otherwise-unmodified maslow 4 if they locked their spools at 45 degree angles.

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