Posts made by jstevewhite

@dc42
Can you clarify the bit I quoted? That's from the duet docs and is very confusing.

Also, any advice since I made this thing left handed?

Ultimately, I've been unable to come up with any combination of reported angles in M669 that result in 0,0 being at the proximal axis. The only even remotely functional settings I've come up with result in 0,0. being way up top and no moves being rectilinear. I made a law of cosines spreadsheet and calculated the angles but there's clearly some rotation here that I don't understand.

@JoergS5

Image of robot (drawbot, not printer):

Please disregard the marked angles as other than an indication of the range of motion.

I do not understand this bit:

The crosstalk factors define how much the motors interfere with each other. If they are all zero then it is assumed that the X motor affects only the angle between the proximal arm and the X axis, the Y motor affects only the angle between the distal arm and the X axis (not the proximal-to-distal arm angle as you might expect), and the Z motor affects only the nozzle height. If this is true for your printer, you can omit the C parameter. Otherwise, if the parameter is of the form Caaa:bbb:ccc, then:

aaa is the amount by which the X motor (whose primary function is to control the proximal arm) affects the angle between the distal arm and the proximal arm. For example, if movement of the proximal motor affects the proximal-to-distal joint angle in reverse (so that an X motor movement that causes one degree of proximal arm movement also changes the angle between the distal arm and the X axis by one degree in the opposite direction) then this crosstalk factor is 1.

They seem to contradict one another.

G92 does not seem to set the angle the machine believes the arms are at, but instead appear to affect cartesian co-ordinates:

10/18/2020, 11:37:13 AM	M114
X:16.886 Y:150.000 Z:0.000 E:0.000 E0:0.0 Count 1391 22457 0 Machine 16.886 150.000 0.000 Bed comp 0.000
10/18/2020, 11:37:08 AM	G92 Y150
10/18/2020, 11:37:00 AM	M114
X:16.886 Y:95.766 Z:0.000 E:0.000 E0:0.0 Count 0 24915 0 Machine 16.886 95.766 0.000 Bed comp 0.000

As you can see, G92 Y150 resulted in Y being set to 150 and X being unchanged, but the reported angles change to something else entirely.

@JoergS5

I'll sure try that tomorrow, but at one point I had it set with the angles correct in M208 for the endstops and it still didn't have 0,0 in the appropriate location.

I'll report back tomorrow

There is clearly a problem with the angles I'm using here because no combination I have tried puts 0,0 at the Proximal axis.

@JoergS5

Here's homedistal.g

G91 ; relative movement
G1 H1 Y-200 F2000 ; move distal joint counter-clockwise until triggers
G1 H2 Y10 ; back off 10 degrees
G1 H1 Y-20 F1200
;G1 H2 Y20
G90

and homeproximal.g

G91 ; relative movement
G1 H1 X200 F1200 ; move distal joint counter-clockwise until triggers
G1 H2 X-10 ; back off 10 degrees
G1 H1 X40 F300
;G1 H2 X20
G90

I do not use homeall.g because I can't make it stop throwing an error trying to home z, even though I have no Z axis configured.

@JoergS5 said in Duet 3 SCARA questions:

A-89.9:90.1 B-130.9:20.0. < this one results in "Intermediate position outside machine limits" for any move at any point in the machine's actual rotational ability.

So I've tried both of those configurations after (once again) correcting the rotation direction (had the distal arm rotating the wrong direction). The first one is similar to a config I've tried. It allows me to do small moves in X and Y, but the co-ordinates are nonsensical - they look right at homing, but 0,0 is maybe 300mm from the Proximal axis and once you cross it any relative move results in a long move that goes out of the working area. E.g. G91; G1 X1 results in a 90º rotation of the proximal axis.

If I read the docs (and dc42) right, 0,0 should be at the proximal axis pivot. Meaning X and Y should be decreasing as the effector moves away from the axis. I'm wondering if I should be using angles in the lower quadrant (negative going on both axes) because the bot is left handed. e.g. 180-360 instead of 0-180.

@JoergS5

So this config line:

M669 K4 P280 D270 A0:180 B25:160 C0:0:0 ; set to SCARA and set params

results in this:

X:-26.283 Y:-92.346 Z:0.000 E:0.000 E0:0.0 Count 16200 14400 0 Machine -26.283 -92.346 0.000 Bed comp 0.000

Which is sorta right ( -26, -92 is "kinda" sane ) but any motion fails with "Target Position not reachable from current position".

I had created macros to move each motor individually some time ago, and the motion direction is appropriate as described by the section you linked (that's where I got my information above) and without them I mostly can't move the motors because any G1 (any number) is met with "Target position not reachable from current position". When I move the motors individually, the x/y co-ordinates don't make any sense in this configuration.

@JoergS5

I've tried this:
M669 K4 P280 D270 A0:180 B160:25 C0:0:0 ; set to SCARA and set params

The proximal arm homes all the way counterclockwise, and the distal arm homes all the way clockwise. I'm not at all certain which way it SHOULD be here. I've tried all four permutations:

M669 K4 P280 D270 A0:180 B160:25 C0:0:0 ; set to SCARA and set params
M669 K4 P280 D270 A0:180 B25:160 C0:0:0 ; set to SCARA and set params
M669 K4 P280 D270 A180:0 B160:25 C0:0:0 ; set to SCARA and set params
M669 K4 P280 D270 A180:0 B25:160 C0:0:0 ; set to SCARA and set params

Any permutation that doesn't have them opposite says X is at 520mm, which would be with the distal arm fully extended.

It's my understanding the angle should be increasing in the counter-clockwise direction, so A0:180 B160:25 should be correct... I think? It's not straightforward at all

M114 still says:

X:-26.283 Y:-92.346 Z:0.000 E:0.000 E0:0.0 Count 16200 14400 0 Machine -26.283 -92.346 0.000 Bed comp 0.000

Config:

; Drives
M569 P0 S1 ; physical drive 0 goes forwards
M569 P1 S0 ; physical drive 1 goes forwards
M584 X0 Y1 ; set drive mapping
M669 K4 P280 D270 A180:0 B25:160 C0:0:0 ; set to SCARA and set params
M350 X16 Y16 I1 ; configure microstepping with interpolation
M92 X90.00 Y90.00 ; set steps per mm
M566 X900.00 Y900.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 ; set accelerations (mm/s^2)
M906 X800 Y800 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Axis Limits
M208 X-1000 Y-1000 S1 ; set axis minima
M208 X1000 Y1000 S0 ; set axis maxima

; Endstops
M574 X1 S1 P"^io0.in" ; configure active-high endstop for low end on X via pin io0.in
M574 Y2 S1 P"!^io1.in" ; configure active-high endstop for low end on Y via pin io1.in

After Homing, M114:

X:-26.283 Y:-92.346 Z:0.000 E:0.000 E0:0.0 Count 16200 14400 0 Machine -26.283 -92.346 0.000 Bed comp 0.000

So 180º and 160º.

Moving each arm -20º ( counterclockwise ) results in:

X:-128.114 Y:-138.061 Z:0.000 E:0.000 E0:0.0 Count 14400 12600 0 Machine -128.114 -138.061 0.000 Bed comp 0.000

So 160 and 140º, as expected.

But a +10 X (any move, actually) move with Dashboard jog controls gets "intermediate positions outside machine limits".

The X and Y locations when homed match measured distances - that is, roughly 92mm from the proximal axis and 26mm offset. But moving the axis with G91; G1 H2 X-20; G90 (a macro) and the x/y co-ordinates are dramatically off.

What am I getting wrong here?

So I decided to build a SCARA drawbot just to learn more about kinematics and for something "cool" to design and build. I'm using 3.2-beta on a beta Duet board.

I built the SCARA left handed due to lack of thought on my part:

I'm currently homing the proximal arm to the top vertical position, and the distal arm to the max extension (about 160 degrees or so)

My kinematic config is:
M669 K4 P267 D267 A0:180 B20:140 C1:0:0 ; set to SCARA and set params

Current config:

M208 X0 Y20 S1 ; set axis minima in degrees
M208 X180 Y140 S0 ; set axis maxima in degrees

; Endstops
M574 X2 S1 P"^io0.in" ; configure active-high endstop for low end on X via pin io0.in
M574 Y1 S1 P"!^io1.in" ; configure active-high endstop for low end on Y via pin io1.in

C1: because the angle between the proximal and distal arm increases as the proximal arm moves clockwise. Proximal goes from 0 at the vertical position in the picture to nearly 180, though I'm actually only moving it to, say, 110 degrees.

G91
G1 H2 X10
G1 H2 Y10
G90

Results in both arms moving 10 degrees (roughly) clockwise.

When I home the arms DWC reports X-517.9 Y-91.3. Any attempt to move gets

Error: G0/G1: target position not reachable from current position

Three questions:

1)Is there anything there that's obviously wrong (ie, "don't make it left handed"); any config suggestions are welcome

2. Is there a way to get the angle of the arms rather than cartesian co-ordinates?

3. Where does it think X=0 Y=0 are, and how do I control that?

Thanks in advance!

@dc42

Ah, ok, that makes sense. Add it to the config-override.g manually. I just wanted to make sure that was an appropriate way to achieve the behavior I'm looking for.

Thanks!

@dc42

Is this intentional behavior? I ask because it seems to leave out anyone who might manually configure multiple tools. I see why mine is working (because i tested touch-off G10 settings for our eventual implementation of the E3D toolchanger on RailCore 2), and it's worked ever since (because it was already there, I suppose).

So in order to make this work manually, you have to manually enter it into config-override.g once, reboot, and then changes will be written?

@phaedrux

Tool offsets are critical to the eventual application of the tool changer to the RailCore chassis. G31 is for PROBE offset - which is fine if you have only one tool, but if you have multiple tools, it's insufficient for configuration.

That's what got me testing it. While testing it, it became clear that the tool offset is MUCH more user friendly. You'll note that bmveee had the same issue prior to switching to the G10 tool offset process, and the issue in the other post that you mention occurred with G31 and G10 tool offset as well.

If G10 doesn't function properly, it's still broken, even if you can work around it with G31. I don't think that's related to this issue, though, but there's certainly something strange going on. The M500 wasn't saving the tool offset like it's supposed to. Specifically, in my gcode console I can issue:

G10 L1 P0

and get:

G10 L1 P0
Tool 0 offsets: X0.00 Y0.00 Z1.70, active/standby temperature(s): 0.0/0.0

This is mirrored in my config-override.g:

; config-override.g file generated in response to M500 at 2019-06-27 16:10
; This is a system-generated file - do not edit
; Heater model parameters
M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B0
M307 H1 A618.9 C194.1 D4.1 S1.00 V24.3 B0
M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0
; Probed tool offsets
G10 P0 Z1.70
G10 L2 P1 X0.00 Y0.00 Z0.00
G10 L2 P2 X0.00 Y0.00 Z0.00
G10 L2 P3 X0.00 Y0.00 Z0.00
G10 L2 P4 X0.00 Y0.00 Z0.00
G10 L2 P5 X0.00 Y0.00 Z0.00
G10 L2 P6 X0.00 Y0.00 Z0.00
G10 L2 P7 X0.00 Y0.00 Z0.00
G10 L2 P8 X0.00 Y0.00 Z0.00
G10 L2 P9 X0.00 Y0.00 Z0.00

while troubleshooting with bmveee or duetal (I think that's mspal from our discord ) I noted that M500 never wrote their tool offset to the config-override.g. This is unexpected behavior, and is sufficient in and of itself to result in unpredictable behavior. That's when I recommended they post in the duet forums.

Specifically, I had one of them put M501 at the end of their config.g (This should load config override). Then issue:

G10 L1 P0 Znnn.n (insert number here)
then
M500
and the entry does not appear in config-override.g as it should. This is clearly a problem, but I can't seem to figure out why. Mine works as expected.

@dc42

We'll have to get @natewalck to provide that data. Somehow, mine suddenly stopped doing this. I repeated it fifteen or twenty times when Nate told me about it, and then for the last repetition you asked for. But somehow running M122 seems to have fixed it permanently. LOL. Not sure how that's even possible.

Changes: I took out the M401/M402 and the dwell. Nothing else except M122.

Now I power cycle, G28, G32, G32, G29 and get the proper map.

@veng1 said in Weird Bed Mesh Behavior after Z-Leveling:

In the first height map, all locations are less than 0.0. What setting would move the center up to Z = 0.0?

That's the $64,000 question, eh? No setting changes between the first picture and the second.

@dc42 -

power on
G28
G32
G32
G28 Z
G29

Ok, reproduction is easy. Every time I follow that procedure I get this map:

It turned out to take more than a few G32/G28 Z/G29 cycles to return to the normal map, which is:

But now, no matter how many times I run G28 Z, G32, or G29, I get the same ( good ) result.

Note that our leveling probe and our mesh probe use the same bed points. Our general assumption is that the 1/4" MIC6 tooling plate is flat (which is born out by actually printing).

Also, I have not tried a print with this map as I'm afraid of a nozzle crash.

@dc42

The G4 P500 is in the wrong place there. I needed it for the servo I was using and it got inadvertently moved. I'll pull the M401 and M402, thanks. I should probably audit my configuration monthly because of all the experimentation I do

natewalk can reproduce it repeatedly. I only did it twice (the whole cycle, power on to bed 0.1mm low ) but it did do it both times. When the print that's currently running is done, I'll try it again and update.

@paulhew

Note that with TR8*8 screws, your "magic number" (Full step height) will be 0.02. All this means is that for best print quality, your layer height should be a multiple of 0.02. So rather than printing at 0.15, you'll want to do 0.16 or 0.14 instead.

I ran the original non-ZL RailCore 2 with this configuration for quite some time (until December of last year) and was quite happy with the prints.

Just remember you'll need to change the configuration for Z steps per mm from the default.

@dc42 - I just want you to remember, as you look through my crufty, constantly-noodled, experimental config.g, that you asked for this pain >:) hehehe

config.g:

; Configuration file for My Printer
; Communication and general
M111 S0 ; Debug off
M550 PRailCore2 ; Machine name and Netbios name (can be anything you like)
;M551 Pmyrap ; Machine password (used for FTP)
;*** If you have more than one Duet on your network, they must all have different MAC addresses, so change the last digits
M540 P0xBE:0xEF:0xDE:0xAD:0xFE:0xEE ; MAC Address
;*** Wifi Networking
M552 S1 ; Enable WiFi
M555 P2 ; Set output to look like Marlin
M575 P1 B57600 S1 ; Comms parameters for PanelDue

G21 ; Work in millimetres
G90 ; Send absolute coordinates...
;M83 ; ...but relative extruder moves

; Axis and motor configuration
M584 X0 Y1 Z5:6:7 E3:4:8:9 ; Map Z to drivers 5, 6, 7 ; Define unused drivers 3,4,8 and 9 as extruders
;M584 X11 Y10 Z5:6:7 E3:4:8:9 ; Map Z to drivers 5, 6, 7 ; Define unused drivers 3,4,8 and 9 as extruders (servos)

; M584 X11 Y10 ; (smartsteppers)
M667 S1
M569 P0 S0 ; Drive 0 goes forwards (change to S0 to reverse it)
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S0 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M569 P5 S1 ; Drive 5 goes backwards
M569 P6 S1 ; Drive 6 goes backwards
M569 P7 S0 ; Drive 7 goes backwards
;M569 P10 S1
;M569 P11 S0

;Leadscrew Locations:
M671 X-10:-10:273 Y24:228:122 S7.5 ; Calibrated Front left, Rear Left, Right S7.5 is the max correction

M92 X160 Y160 Z1600 ; set steps/mm for 1/16; later changes in M350 will be adjust0d
M92 E800:800 ; set steps/mm for 1/16; later changes in M350 will be adjusted.
;M350 X32 Y32 Z32 E16 I1 ; set 16x microstepping with interpolation
;M350 X64 Y64 Z128 E16 I1 ; set 128 microstepping for axes, 64 for extruder "with interpolation
M350 X16 Y16 Z16 E16:16 I1 ; set everything to 1/16, with interpolation.
M574 X1 Z0 S0 ; set homing switch configuration (x,y at min, z at max)
M574 Y1 S1
M906 X1500 Y1500 Z800 E1000:800 ; Set motor currents (mA)
;M906 X1200 Y1200 Z1000 E1200:1200 ; old NEMA23
;M906 X580 Y580 Z1000 E1200 ; new 0.9 NEMA23
M201 X2500 Y2500 Z60 E1000:1000 ; Accelerations (mm/s^2)
M203 X24000 Y24000 Z1200 E3600:3600 ; Maximum speeds (mm/min)
M566 X500 Y500 Z120 E600:600 ; Maximum jerk speeds mm/minute
M208 X242 Y240 Z245 ; set axis maxima and high homing switch positions (adjust to suit your machine)
M208 X0 Y0 Z-0.5 S1 ; set axis minima and low homing switch positions (adjust to make X=0 and Y=0 the edges of the bed)

G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

; Thermistors
M305 P0 T100000 B3950 R4700 H0 L0 ; Put your own H and/or L values here to set the bed thermistor ADC correction
;M305 P1 T100000 B3950 R4700 H0 L0 ; Put your own H and/or L values here to set the first nozzle thermistor ADC correction
;M305 P2 T100000 B4240 R4700 H0 L0
M305 P1 T500000 B4723 C1.196220e-7 R4700; Set thermistor + ADC parameters for heater 1 (Slice Engineering)
;M305 P2 T100000 B4240 R4700 H0 L0
M305 P103 X6 S"Chamber" ; virtual heater to show chamber temp

;M301 H1 P26.5370 I1.4191 D124.0605 T0.50 S1.0
;M307 H1 A587 C47.9 D3.1 B0 S1.0 ; auto-tune values from M303 H1 P0.4 S265 with fan on S200 for deltaprintr.mini
;M307 H1 A516 C180 D12.4 B0 S1.0 ; auto-tune values from M303 for fake B3
;M307 H1 A468 C150.1 D6.5 B0 S1.0 ; fake B3 also
;M307 H1 A479.0 C108.6 D5.6 B0 S1.0 ; stubby
;M307 H1 A270.7 C90.4 D6.7 B0 S1.0 ;Heater 1 model: gain 270.7, time constant 68.4, dead time 6.7, max PWM 1.00, in use: yes, mode: PID
M307 H1 A569.0 C285 D4.5 B0 S1.0 ;Heater 1 model: gain 559.4, time constant 283.4, dead time 4.5, max PWM 1.00, calibration voltage 24.4, mode PID, inverted no, frequency default
M307 H0 A90 C700 D10 B0 S1.0
M307 H2 A270.7 C90.4 D6.7 B0 S1.0
;M307 H1 A388.8 C168.7 D12.0 S1.00 B0 ;
M307 H3 A-1 C-1 D-1 ; set duex4 "heater 3" to control the BLTouch
M570 S360 ; Hot end may be a little slow to heat up so allow it 180 seconds
M143 S285

; Fans
M106 P0 H-1 ; disable thermostatic mode for fan 0
M106 P1 T45 H1 ; Turns on fan 45C
M106 P0 S0 ; turn off fans
;M106 P1 S0
M106 P2 S0

; Tool definitions
M563 P0 D0 H1 ; Define tool 0
G10 P0 S0 R0 ; Set tool 0 operating and standby temperatures

;M563 P1 D1 H2
;G10 P0 S0 R0
;*** If you have a single-nozzle build, comment the next 2 lines
;M563 P1 D1 H2 ; Define tool 1
;G10 P1 S0 R0 X0 Y17 ; Set tool 1 operating and standby temperatures
;M92 E837 ;titan steps/mm
;M92 E663:663 ; Set extruder steps per mm

; Z probe and compensation definition
;*** If you have a switch instead of an IR probe, change P1 to P4 in the following M558 command
;M558 P1 X0 Y0 Z1 F900 ; Z probe is an IR probe and is used for homing Z
;M558 P4 X0 Y0 Z1 I1 F900 ; inductive Z probe, inverted
;M558 P9 X0 Y0 Z1 H5 F400 T6000 ; bl-touch
M558 P4 C8 I1 ; OptiCon
M307 H4 A-1 C-1 D-1 ; reserve heater 4 for BLTOUCH
M307 H5 A-1 C-1 D-1
M557 X30:210 Y30:210 S180 ; set mesh size

;*** If you are using axis compensation, put the figures in the following command
;M556 S78 X0 Y0 Z0 ; Axis compensation here

M208 S1 Z-5 ; set minimum Z
;
T0 ; select first hot end
;G31 X0 Y30 Z0.0 P1 ; Set the zprobe height and threshold (put your own values here)
G31 X-4 Y30 Z0 P1 ; set Z offset for use with tool offset
M564 H0
M501 ; load config-override

homez.g:

G91 ; Relative coordinates
G1 Z8 F200 ; Lower bed.
G4 P500 ; Dwell for 500ms - to ensure bed is down
G90 ; Absolute positioning
G1 X125 Y125 F3000 ; Go to center of bed and probe Z height
M401 ; Lower Z probe (BLTouch)
G30 ; Calibrate Z-axis
M402 ; Retract Probe
;G1 Z1 F200 ; Raise bed to 1mm.

homeall.g:;

homeall by executing individual axes homing macros
M98 Phomex.g
M98 Phomey.g
M98 Phomez.g

For 0.01mm full step layer height ( "Magic Number" ) you need either 0.9º steppers with 4mm lead (2-start T8) leadscrew or 1.8º steppers with 2mm lead (1 start T8). That said, 0.9º steppers work fine with 2-start T8; you get lower vertical speed but a full step height of 0.005mm. You can find this information here:

https://railcore.github.io/hardware/leadscrews.html

As far as motors go, the Z axis is heavily reduced (in the sense of mechanical advantage), so torque is almost irrelevant. If you need high jerk or accel on Z - like if you want high speed moves on Z in the case of a ZLT - you'll want beefier motors. But be careful; a failed probe can break stuff!