@breed I find CAMBAM works well for me:
There’s a decent free evaluation period. If you are only doing small jobs (<1000 lines of gcode) I believe you can continue to use it for free. If you find it suits your needs then it’s not too expensive (£93 one off charge).
I’ve found the documentation clear and the forum helpful.
@roiki11 Thanks very much for the explanation - helps me to understand better!
@rjenkinsgb Apologies for a NOOB question but as many CAM programs seem capable of generating effective tool paths without requiring the G40,G41,G42 tool path offsets, what benefit does having them bring?
@jvp79 Hmmmh...
Your measurements indicate the converter is connected and being powered correctly so what else would stop it working?
Perhaps the PWM frequency is outside of the range of the converter? Looking at the Ooznest instructions I see the following command is used to configure the PWM:
M950 R0 C"e0heat" L0:25000 Q100
This sets the PWM frequency to 100Hz, whereas the quoted minimum frequency for the converter is 1KHz, so perhaps try adding an extra zero to set the PWM frequency to 1KHz like so:
M950 R0 C"e0heat" L0:25000 Q1000
Otherwise, it sounds as though the converter might be faulty...
@jvp79 Just as a sanity check, you're seeing + (positive) 24V and not - (negative) 24V?
@jvp79 It’s probably worth using your multimeter to check the voltage between pin 3 (multimeter red lead) and pin 4 (multimeter black lead) of the PWM module.
With the power on, this should read +24V.
@dc42 Thanks for clarifying the M669 reporting of S and T.
There has been some discussion of setting S and T to small values, so that the time delay and distance moved after a pause command can be reduced.
I wondered whether you be able to explain a little more about any trade offs as S and T are reduced ?
@droftarts It appears that M669 doesn’t report the S and T values? This is my console output:
26/11/2021, 21:11:46: Connected to 192.168.0.9
26/11/2021, 21:12:19: M669 S0.001
26/11/2021, 21:12:32: M669: Kinematics is Cartesian, matrix:
1.00 0 0
0 1.00 0
0 0 1.00
26/11/2021, 21:12:46: M669 S1.0
26/11/2021, 21:12:52: M669: Kinematics is Cartesian, matrix:
1.00 0 0
0 1.00 0
0 0 1.00
26/11/2021, 21:14:17: M669 S1.0 T1.0
26/11/2021, 21:14:27: M669: Kinematics is Cartesian, matrix:
1.00 0 0
0 1.00 0
0 0 1.00
@droftarts Thanks, Ian. Will have a go this weekend…
I have a few questions regarding the M669 S and T parameters which I’d be grateful for any help with:
What are the minimum allowable values for the S and T parameters?
If I set S0.1 does this mean I can be confident my CNC will pause within 0.1 seconds?
Similarly, if I set T0.1, does this mean the CNC will pause within 0.1mm?
@cncmodeller
I think it’s definitely worth trying and I’d be interested to hear the outcome as it would give a direct measurement of spindle RPM.
However, from what I’ve seen, I believe the Duet fan rpm input expects two pulses per revolution, so perhaps try a two pulse encoder wheel?
A point to check is whether the optical end stop has any electrical filtering, as this might need to be adjusted to avoid limiting the maximum rpm that can be measured.
@dc42 The board looks to be double sided so one would have to desolder the terminal and cut both sides of the PCB - might be doable but not straightforward.
I agree that having a common Duet-VFD ground is not optimal, but this board has used by others successfully using the pull-up resistor approach.
A properly opto-isolated VFD interface board that provides a 0-10v analogue control signal and RUN, FWD/REV control signals (and ideally rpm feedback) would be a useful add-on for the growing Duet eco-system and make life simpler for many CNC users.
@dc42 From the image of the PCB, I believe this is another of those converter boards with an opto-isolator whose purpose is negated by being connected to ground on the board.
Hence the @alankilian connection with a pull up resistor is needed.
@jack_kelley OK, then I’d suggest using a multimeter to check:
a) that you have the correct DC input voltage on your Duet VIN (12V or 24V?)
b) that the output from the Duet E0 heater pin is behaving as expected by disconnecting the PWM converter board but leaving the 4.7K resistor in circuit and then measuring the DC voltage on the E0 heater pin for each of the following commands:
Command Should give
M3 0 Duet VIN
M3 6000 Duet VIN/2
M3 12000 0V
If both a) and b) check out, then your PWM board is probably dead.
@jack_kelley
This connection for the pull up resistor should work:
As this connection inverts the polarity of the PWM signal I think you will probably need to add an exclamation mark in front of the "e0heat" pin reference in your M950 config command, along the lines of:
; CNC Mode (NB for Firmware 3.3+)
M453 ; CNC Mode
; Configure Tool 0 as the CNC Spindle
M950 R0 C"!e0heat" Q2000 L0:12000 ; Create spindle index 0 with
; inverted PWM output on E0 heater pin
; and spindle speed of 12000 rpm at maximum PWM
M563 P0 R0 S"Spindle" ; Create Tool 0 with Spindle 0 and call it Spindle
G10 P0 X0 Y0 Z0 ; Set Tool 0 axis offsets
M568 P0 F0 ; Set Tool 0 to default RPM of 0
T0 ; Select Tool 0
To get the necessary 5V signal for this converter board you’ll need to add a pull up resistor.
@alankilian described a way of doing this here:
https://forum.duet3d.com/post/242329
The OP on this topic found @alankilian’s method worked with a 4.7K resistor value.
@thekm Here you go….
; Configuration file for Duet WiFi (firmware version 3.3)
; executed by the firmware on start-up
; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"AlphaCNC" ; set printer name
; Network
;M551 ; set password
M552 P192.168.0.9 S1 ; enable network and set IP address
M553 P255.255.255.0 ; set netmask
M554 P192.168.0.1 ; set gateway
M586 P0 S1 ; enable HTTP
;M586 P1 S1 ; enable FTP
;M586 P2 S1 ; enable Telnet
; Drives
M569 P0 S0 ; physical drive 0 goes backwards
M569 P1 S0 ; physical drive 1 goes backwards
M569 P2 S0 ; physical drive 2 goes backwards
M584 X0 Y1 Z2 ; set drive mapping
M350 X256 Y256 Z256 I0 ; configure microstepping without interpolation
;M92 X6400.00 Y6400.00 Z6400.00 ; set steps per mm (Nominal)
M92 X6372.34 Y6380.86 Z6376.35 ; set steps per mm (After calibration)
M566 X900.00 Y900.00 Z12.00 ; set maximum instantaneous speed changes (mm/min)
M203 X2400.00 Y2400.00 Z240.00 ; set maximum speeds (mm/min)
M201 X200.00 Y200.00 Z20.00 ; set accelerations (mm/s^2)
M906 X1200 Y1200 Z1200 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
; Axis Limits
M208 S1 X-102 Y-85 Z-100 ; set axis minima (S1)
M208 S0 X102 Y85 Z80 ; set axis maxima (S0)
; Endstops
M574 X1 S1 P"!xstop" ; configure active-low endstop for low end on X via pin !xstop
M574 Y1 S1 P"!ystop" ; configure active-low endstop for low end on Y via pin !ystop
M574 Z2 S1 P"!zstop" ; configure active-low endstop for high end on Z via pin !zstop
; Z-Probe
M558 P5 C"^!e0stop" H10 F120 T1800 ; set Z probe on e0stop, pull up, normally open, type=switch, dive speeds = 120mm/min
G31 P25 X0 Y0 Z19.2 ; set Z probe trigger value, offset and trigger height
;M557 X15:205 Y15:170 S40 ; define mesh grid
; Heaters
M140 H-1 ; disable heated bed (overrides default heater mapping)
M950 H3 C"nil" ; disable heater3 (pin exp.8 on the expansion connector)
M950 H4 C"nil" ; disable heater4 (pin exp.13 on the expansion connector)
; Fans
;M950 F0 C"nil" ; disable fan 0
M950 F0 C"!fan0+^exp.pb6" Q1000 ; Fan 0 uses the Fan0 output. inverted for PWM, and PB6 as a tacho input with pullup resistor enabled for VFD speed feedback
M950 F1 C"nil" ; disable fan 1
M950 F2 C"nil" ; disable fan 2
; Custom settings
; M591 D0 C3 P2 E6.0 ;This is the command for filament monitoring using an optical on/off switch
; PanelDue
M575 P1 B57600 S0 ; allow commands without checksums to be sent
;Scale cartesian axes
M579 X1.000 Y1.000
; CNC Mode (Firmware 3.3)
M453 ; CNC Mode
;Configure Tool 0 as the CNC Spindle
M950 R0 C"exp.13+exp.8+exp.9" Q2000 L0:25400 ; Create spindle index 0, PWM frequency 2KHz, max rpm = 25.4K ( tweaked to yield 24K)
; and the following connections:
; spindle speed PWM pin : exp.13 pin
; spindle run pin : exp.8
; spindle direction pin : exp.9
M563 P0 R0 S"Spindle" ; Create Tool 0 with Spindle 0 and call it Spindle
G10 P0 X0 Y0 Z0 ; Set Tool 0 axis offsets
M568 P0 F0 ; Set Tool 0 to default RPM of 0
T0 ; Select Tool 0
; CNC Emergency Stop
M950 J0 C"exp.4" ; Define exp.4 as input pin 0 (P0) for use as an emergency stop input
M581 T0 P0 S1 R0 ; Trigger an emergency stop (T0) when input pin 0 (P0) edge occurs
; Miscellaneous
M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss
@redvernon Happy to help and thanks for sharing the solution.
@redvernon Understood. Perhaps it would be worth trying to install the CNC version of DWC directly?
I believe the latest version (CNC-08) is here:-
https://github.com/Duet3D/DWC-CNC/releases/tag/3.3.0-CNC08
After doing this you can check the correct version is installed by selecting Settings/General which should show the version of DWC like this:
.