Commissioning multi extruder Mendel 3
Posted by bgkdavis
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Commissioning multi extruder Mendel 3 July 03, 2015 06:56AM |
Whilst commissioning the second and third extruders on my RepRapPro Mendel 3 I came to the conclusion that the instructions were lacking so decided to design a method for quickly setting and checking the position of the nozzles.
During the development of this test I also realized that I had a pretty good way of setting and checking the XY orthogonal accuracy of my printer, so have included that test in the same file.
First print the attached file, it should give you a single layer print of 6 concentric octagons with the outer one measuring 100m across flats, the 3 inner ones are sacrificial just to make sure the extruders are running properly before printing the calibration shapes,it doesn't matter too much that the shapes are incomplete, just so long as they are well adhered to the platen.
OCT.txt
To correct the XY offsets of the second and third extruders
Step 1 If you can remove your platter best do so, do not disturb the three outer octagons, but feel free to remove the three inner ones
Step 2 with a digital caliper you can measure the out of concentricity error between the outer and two inner octagons
To measure the XY orthogonal error
Ignoring the inner octagons measure the distance across the two diagonal flats, and call them diag1 and diag2, diag1 should be the diagonal closest to your XY home point.
the correction factor is now diag1-diag2, aand the measure distance is 100mm, ie on my Mendle 3 the two measurements I got were 99.8 and 100.2 respectively so my G code for orthogonal compensation looks like this....
M556 S100 X-0.4 Y0 Z0
if you need to use a different S factor then you can convert the measurement as follow
(diag1-diag2)*75/100.... where 75 is the S factor your want to use
During the development of this test I also realized that I had a pretty good way of setting and checking the XY orthogonal accuracy of my printer, so have included that test in the same file.
First print the attached file, it should give you a single layer print of 6 concentric octagons with the outer one measuring 100m across flats, the 3 inner ones are sacrificial just to make sure the extruders are running properly before printing the calibration shapes,it doesn't matter too much that the shapes are incomplete, just so long as they are well adhered to the platen.
OCT.txt
To correct the XY offsets of the second and third extruders
Step 1 If you can remove your platter best do so, do not disturb the three outer octagons, but feel free to remove the three inner ones
Step 2 with a digital caliper you can measure the out of concentricity error between the outer and two inner octagons
To measure the XY orthogonal error
Ignoring the inner octagons measure the distance across the two diagonal flats, and call them diag1 and diag2, diag1 should be the diagonal closest to your XY home point.
the correction factor is now diag1-diag2, aand the measure distance is 100mm, ie on my Mendle 3 the two measurements I got were 99.8 and 100.2 respectively so my G code for orthogonal compensation looks like this....
M556 S100 X-0.4 Y0 Z0
if you need to use a different S factor then you can convert the measurement as follow
(diag1-diag2)*75/100.... where 75 is the S factor your want to use
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