Quote

**hercek**

... There are at least three ways to mitigate this problem:

... There are at least three ways to mitigate this problem:

- Z-height adjusting based on XY position. The part will be imprecise (as tilted as the bed/towers).

...

True; but that can be corrected by using orthogonal axis compensation (M556). I had it in mind to do this automatically in RRF, but I haven't got around to it yet.]]>

I was not referring to tower tilt but bed tilt, which is the 8th factor. I am presuming that bed tilt factors into the endstop values, and does not rely on a specific routine in the firmware.]]>

Quote

**DjDemonD**

Hi David, any chance of the least squares online calculator being updated to do 8 and 9 factor calibration, and to auto generate more than 7 points?

Hi David, any chance of the least squares online calculator being updated to do 8 and 9 factor calibration, and to auto generate more than 7 points?

It does allow 10 points. I couldn't find anything in Repetier to do with tower tilt either.]]>

It is good when printers with bowden have constant maximum print head speed so that extrusion is more even over the whole build plate. Different print speeds need different pressure in the hotend and proper pressure management is not easy through bowden ... especially for the case like this where head speed changes non-trivially depending on XY position.]]>

When one arm is almost horizontal there is no choice but to slow the head down otherwise that carriage will be unable to keep up and move accurately, as it has to move proportionally far further than the other two for any given head movement on the extremities of the printable area.

I'm just curious but what does this information help you with?]]>

Did they change the speed limit code so that it applies to the print head speed?]]>

The only difference between DC2 and AC is how this displacement matrix is build and solved: DC2 does that within the FW, which requires some more RAM space but can deal with any configuration of probe points; while in AC the displacement matrix has been calculated and solved externally (in Excel) once and for all for an equally spaced circular probe grid

Rich Cattell Marlin, Marlin Kimbra,... do iterate towards a solution by switching between end-stop iteration, delta radius iteration and tower angle iteration using specific formulae for each, thus requiring approx. 3x more iterations than a displacement matrix method.

Extending the online calculator to correct for be tilt would have little value, because AFAIK no other firmware provides configuration parameters for correcting for bed tilt. In any case, I am very busy right now with firmware for some exciting new developments in 3D printing.

The online calculator already allows you to generate more than 7 points. AFAIR the limit is either 13 or 16.]]>

Quote

**roboprint**

David, do you have the opportunity to add simple M665 and M666 command parameters parser to fill initial parameters of calculator? Just field (like commands field at the end of calculator) where user can enter M665 and M666 commands from his config to fill initial values.

Also simple list of G1 commands to move effector close to each probe point would be useful too. The user will be able to copy command directly to console to move effector to next probe point.

David, do you have the opportunity to add simple M665 and M666 command parameters parser to fill initial parameters of calculator? Just field (like commands field at the end of calculator) where user can enter M665 and M666 commands from his config to fill initial values.

Also simple list of G1 commands to move effector close to each probe point would be useful too. The user will be able to copy command directly to console to move effector to next probe point.

That's all possible to do, however I have to implement an urgent requirement for additional axes and IDEX support in RepRapFirmware. So it's not likely to happen any time soon unless someone else contributes the code.]]>

Also simple list of G1 commands to move effector close to each probe point would be useful too. The user will be able to copy command directly to console to move effector to next probe point.]]>

G1 X129.9 Y75 Z30 F5000

G1 X129.9 Y-75 Z30 F5000

G1 X0 Y-150 Z30 F5000

G1 X-129.9 Y-75 Z30 F5000

G1 X-129.9 Y75 Z30 F5000

G1 X0 Y75 Z30 F5000

G1 X64.95 Y-37.50 Z30 F5000

G1 X-64.95 Y-37.50 Z30 F5000

G1 X0 Y0 Z30 F5000

So these kind of points are ok for you ?

X-32.5 Y18.8

X-32.5 Y18.8

X0 Y-37.5]]>

I have made many improvments in my printers...

1/ V-slot carriage modification : Back plate

2/ Hotbed plate

3/ endstop NC (before NO)

So the results are good I think : 0.03 !!!

I must do a 7 factors configuration to have this value.

With only 6 factors, I cannot do better than 0.11.

My results :

Before / after 0.11 with 6 factors

M665 R164.74 L349.00 H470.86 B150.00 X-0.15 Y-0.83 Z0.00

M666 X0.36 Y0.31 Z-0.66

0.16

-0.19

0.08

-0.14

0.14

-0.11

-0.02

0.05

0.04

-0.08

Before 0.11 / after 0.03 with 7 factors

M665 R166.96 L356.55 H470.90 B150.00 X-0.14 Y-0.79 Z0.00

M666 X0.36 Y0.27 Z-0.62

0.02

0.00

-0.02

0.02

-0.01

0.02

-0.05

0.04

0.02

-0.06

What do you think about this results ?]]>

Quote

**shofman**

Is it important that the hotend is perpendicular with the effector ? I think I have a problem with this (play between them ).

Is it important that the hotend is perpendicular with the effector ? I think I have a problem with this (play between them ).

If there is play between the hot end and the effector, you definitely need to get rid of it.]]>

Quote

**shofman**

Ok I will do this.

Do you have a checklist of the typical geometrical errors in a delta build ?

Ok I will do this.

Do you have a checklist of the typical geometrical errors in a delta build ?

Rods not all the same length between bearings

Bearing spacing not quite the same at the top of a pair of rods as at the bottom

Carriage rotated about its face so that the two bearings on it are not at the same height (bearings on the effector being at different heights will have the same effect)

Carriage rotated about the Z axis so that the rods attached to it are trying to twist the effector a different amount than the other carriages

Play in the joints, which is taken up in different directions depending on effector XY position, due to the Bowden tube exerting sideways forces in different directions]]>

Before (3 tries before that)

M665 R169.24 L349.00 H487.08 B150.00 X-0.47 Y-0.69 Z0.00

M666 X-0.50 Y0.42 Z0.08

G1 X0 Y150 Z30 F5000

G1 X129.9 Y75 Z30 F5000

G1 X129.9 Y-75 Z30 F5000

G1 X0 Y-150 Z30 F5000

G1 X-129.9 Y-75 Z30 F5000

G1 X-129.9 Y75 Z30 F5000

G1 X0 Y75 Z30 F5000

G1 X64.95 Y-37.50 Z30 F5000

G1 X-64.95 Y-37.50 Z30 F5000

G1 X0 Y0 Z30 F5000

Measures :

-0.07 (Z tower)

-0.01

-0.12 (in front of Y tower... strange ?)

-0.01

0.03 (X tower)

0.07

-0.07

0.14

0.10

-0.10 (Center)

deviation before 0.08 after 0.07

Propostion :

6 factors :

M665 R169.19 L349.00 H487.07 B150.00 X-0.51 Y-0.64 Z0.00

M666 X-0.59 Y0.44 Z0.15

7 factors (after 0.07 too)

M665 R168.82 L347.83 H487.06 B150.00 X-0.51 Y-0.64 Z0.00

M666 X-0.59 Y0.44 Z0.15

I have a great difference between the 3 center points (the 3 last)... So the first layer is not good at all. Brim is awfull.

What do you think about this results ?]]>