Error in calibration of triangular kinamatics

I have entered rotation radius = 345mm
height of motors = 420 mm from plywood
Distance between motors = 3001 mm

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From the center line of motors to plywood sheet distance is 420mm

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Can you post a picture of your frame?

I ran your numbers through calibration simulator and end up with:

Motor Y Offset: 274.841
Rotational Radius: 315.473
ChainSag: 802.8

Is it possible you measured the cuts wrong?

270.9 is actually very low… about 10-inches. Mine is 468 mm (18 inches)

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I’ve measure the cut right only about an error of 1 mm or so

The actual hight I’ve measure is about 420mm

My links are made of aluminum, is it effect the calibration due to its weight?

The cuts are supposed to be around 1930 mm wide… cutting 1874 and 1834 is a big difference, that’s why I ask. When you do the cuts the first time, you should be much closer assuming your motor spacing is good and your estimates for rotational radius and vertical height are correct.

Perhaps do:

Actions->Advanced->Wipe EEPROM


Actions->Advanced->Reset settings to defaults


Go back into settings and change the chain pitch back to 10mm again.

then run calibration another time… and see if your first set of cuts gets closer to 1930-ish

If anything, I would expect it to be a smaller chain sag value.

Can you describe your linkage kit (maybe post a picture)… 315 mm rotational radius seems higher than what I’ve seen to date.

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that’s a very high rotation radius, a little over a foot from the center of the bit to the end of the chain

A picture is sometimes more then a thousand words.

That’s how my machine looks

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Do those linkage arms hit the bricks? If so, that will throw everything off.

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The wood for the motors looks like it will flex allot. Have you measured if you have a different motor distance with 1) sled at the bottom of the sheet 2) sled at the top of the sheet?

Also, the bolts holding the arms are going to flex under sideways tension.
measure the distance between the top bolts at the top center vs when the chains
are slack.

David Lang

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Nope like, these are free

When the sled goes upward, it looks like the lower arms will hit the bricks. Can you post a picture with the sled at the top of the workarea?