Polar kinematics type 3D printer software setup help

dc42 · 14 Dec 2019, 07:21

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.2 on Thu Nov 14 2019 21:46:59 GMT-0800 (Pacific Standard Time)
;home radius X first
G91 ; relative positioning
G1 H2 Z4 F6000 ; lift Z relative to current position
G1 H1 X111 F3000 ; move radius towards MAXIMUM until the endstop switch is triggered
G1 H2 X100 ; move radius IN by 11mm
G1 H1 X113 F600 ; move radius slowly to the endstop switch again

Your G1 H1 move homes to the endstop switch successfully. But you are still in relative mode when you execute the next 2 G1 commands, so it continues to try to move in the same direction.

iamthebest22 · 14 Dec 2019, 08:23

ah so should I change the homeall and homeradius (since they use the same gcode) part to:

;home radius X first
G91 ; relative positioning
G1 H2 Z4 F6000 ; lift Z relative to current position
G1 H1 X111 F3000 ; move radius towards MAXIMUM until the endstop switch is triggered
G1 H2 X-11 ; move radius IN by 11mm
G1 H1 X12 F600 ; move radius slowly to the endstop switch again

is this correct?

dc42 · 14 Dec 2019, 13:48

Yes, that looks better.

iamthebest22 · 14 Dec 2019, 18:30

Thank you very much, it works now, now the question since this is so much different than a cartesian or usual corexy, is there a gcode where I can test it "printing" (I forgot what the function is called, basically it's not actually printing just repeating the loop) a 20mm by 20mm cube to see if I got the Y axis right? (the X and Z has been fully calibrated since they are straight, just the Y since it's the a turntable now). Thanks.

iamthebest22 · 14 Dec 2019, 18:55

Also another question (sorry for so many question new at Polar kinematics), when I press to increase Y axis (say +10) the turntable turns counterclockwise, is that correct or should it be clockwise when I increase Y ?

JoergS5 · 14 Dec 2019, 20:20

A Y movement or a X movement is translated into a rotary plus linear movement of the polar printer.
X and Y are the coordinates which are used by the G-Code file and are the real word coordinations, perpendicular.
The polar printer on the other side has a rotation movement and a linear movement.

The X and Y coordinates are translated by firmware to the stepper commands for rotation and linear motion.

So your G-Code commands for X, Y, Z, are the same like for a cartesian, delta, corexy... printer. The firmware translates it, depending on the printer type.

For a test print, you need a model (often stl format) of the cube and create a gcode file in a program e.g. Cura. This g-code file can be uploaded to Duet and printed.

To see if your rotation is correct, I would look which line the nozzle draws (imaginary) on the print bed.

iamthebest22 · 14 Dec 2019, 23:30

@JoergS5 yeah that's what I mean, so I guess I'll just slice a 20mm cube in the slicer of my choice and upload it and Simulate file in the Duet and then see what it does? Thanks.

Danal · 15 Dec 2019, 01:25

@iamthebest22 said in Polar kinematics type 3D printer software setup help:

@JoergS5 yeah that's what I mean, so I guess I'll just slice a 20mm cube in the slicer of my choice and upload it and Simulate file in the Duet and then see what it does? Thanks.

Yep. Or even take the "heat" command out and print it with no filament, if you want to watch it move.

iamthebest22 · 15 Dec 2019, 02:14

@Danal oh yeah I need to take that out, that always bugged me how it still turns on heater for that. So what you mean is I edit the gcode to take out the temp right?

iamthebest22 · 15 Dec 2019, 02:20

Another question just came up, i haven't set which bed leveling system I should use, now according to https://duet3d.dozuki.com/Wiki/Using_mesh_bed_compensation there's two types, one for cartesian/corexy, and the other for a delta printer. I'm assuming since I'm using Polar type and it has a circular bed, I should use the Delta type? So my M557 should look something like this?

M557 R80 S20 ; probe within a radius of 80mm from the centre with a mesh spacing of 20mm

is this correct?

currently it's this:
; Z-Probe
M558 P9 H5 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-17 Y22.5 Z2.5 ; set Z probe trigger value, offset and trigger height
M557 X15:70 Y15:75 S20 ; define mesh grid

Should I change it to:
; Z-Probe
M558 P9 H5 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-17 Y22.5 Z2.5 ; set Z probe trigger value, offset and trigger height
M557 R80 S20 ; probe within a radius of 80mm from the centre with a mesh spacing of 20mm

Thanks.

dc42 · 15 Dec 2019, 11:21

@iamthebest22 said in Polar kinematics type 3D printer software setup help:

Also another question (sorry for so many question new at Polar kinematics), when I press to increase Y axis (say +10) the turntable turns counterclockwise, is that correct or should it be clockwise when I increase Y ?

That sounds wrong to me, I think it should be clockwise, otherwise your prints will come out mirrored. Use the M569 S parameter to change the direction of the Y driver.

iamthebest22 · 15 Dec 2019, 16:56

@dc42 good to know, btw should I change the mesh probe map setting to what I said above? from the current M557 X15:70 Y15:75 S20 ; define mesh grid to

M557 R80 S20 ; probe within a radius of 80mm from the centre with a mesh spacing of 20mm since it's a circular bed?

Danal · 15 Dec 2019, 17:23

@iamthebest22 said in Polar kinematics type 3D printer software setup help:

@Danal oh yeah I need to take that out, that always bugged me how it still turns on heater for that. So what you mean is I edit the gcode to take out the temp right?

Yep. If you wish to watch the printer a few times before you print, edit the temp commands (there will be three or four) out of the beginning of the G-Code file, unload filament, and print. Then you can observe.

Danal · 15 Dec 2019, 17:24

And I'm not 100% certain on probe... but, were it me, I'd start with Delta-style.

iamthebest22 · 16 Dec 2019, 04:04

@Danal I think Delta style worked, now since my furthest offset is 22.5 on the Y.... I'm really not sure if I have the offset correct to be honest. I took a video cause I don't think photos would make it easier, but here's what I got for the X and Y offset (ignore Z for now, that's easy for me)

G31 P500 X-17 Y22.5 Z2.5 ; set Z probe trigger value, offset and trigger height

and the video, https://www.dropbox.com/s/0nzm7cikaxfzp2z/2019-12-15 20.02.39.mp4?dl=0

dc42 · 16 Dec 2019, 20:14

@iamthebest22 said in Polar kinematics type 3D printer software setup help:

@dc42 good to know, btw should I change the mesh probe map setting to what I said above? from the current M557 X15:70 Y15:75 S20 ; define mesh grid to

M557 R80 S20 ; probe within a radius of 80mm from the centre with a mesh spacing of 20mm since it's a circular bed?

The only issue I can see with that is that it will try to probe at X0 Y0, which may be unreachable depending on your probe offset.

dc42 · 16 Dec 2019, 20:26

@iamthebest22 said in Polar kinematics type 3D printer software setup help:

@Danal I think Delta style worked, now since my furthest offset is 22.5 on the Y.... I'm really not sure if I have the offset correct to be honest. I took a video cause I don't think photos would make it easier, but here's what I got for the X and Y offset (ignore Z for now, that's easy for me)

G31 P500 X-17 Y22.5 Z2.5 ; set Z probe trigger value, offset and trigger height

and the video, https://www.dropbox.com/s/0nzm7cikaxfzp2z/2019-12-15 20.02.39.mp4?dl=0

In answer to the questions in your video:

Assuming that you haven't set a nozzle offset, the carriage is at X=0 when the nozzle is over the rotation axis of the turntable. It's up to you to decide which direction from that you want to be +X. If the nozzle can reach the edge of the bed when it moves in one direction, but not when it moves in the opposite direction, I suggest you make the first direction +X. RRF will only make use of positive X values.

Now orient yourself in relation to the printer with +X to the right. +Y will be away from you. If the Z probe is to the right of the nozzle, the probe X offset is positive, else it is negative. If it is further away from you than the nozzle, that's in the +Y direction so the probe Y offset is positive. If it is nearer you than the nozzle, that's a negative Y offset.

If the nozzle is printing at Y=0 and it needs to go to a positive Y point, that positive Y point is further away from you than the radius arm, so the turntable will need to rotate clockwise to bring that point under the radius arm. So clockwise turntable motion is positive.

I don't have a polar printer, so I can't guarantee that the above is 100% correct.

HTH David

iamthebest22 · 17 Dec 2019, 00:53

@dc42 Ah I think I got it, I was in the wrong orientation of the video, so I think I got it, I went to the other side as you can see in this new video, so +x is to the right, so the BLtouch is to the left of the nozzle, so that's -x for sure.

As for the Y I think I got it too, since it's closer to the nozzle to me, that means it's negative too, thanks.

new video: https://www.dropbox.com/s/tk43aqloukbb8m9/2019-12-16 16.42.25.mp4?dl=0

dc42 · 17 Dec 2019, 13:34

Yes that looks correct to me.

shadi · 22 Apr 2021, 21:25

@iamthebest22 just want to know if you have managed to run the machine output correctly, I have designed a machine that has polar coordinates where Y is turntable and X and Z are moving on the plate basically machine should move theta in Y and R on X , I would ask your help if you managed to resolve the issues you are facing on your machine for me the machine prints a skewed shapes with round edges and i am not able to come over this machine shape is flipped L where the base is Y , Z goes up and down and X moves by R value .