Posts made by rs4race

I was able to confirm this works as expected.

As always thanks for the quick reply. This is what I was hoping for, but just to double check if I were to add the following to my start script:

G10 L2 P2 X50 Y50 Z0 ; set offsets for coordinate system G55, sets G55 origin at X50Y50Z0
G55 ; Use coordinate system G55

I should expect the toolpaths to shift 50 in X and 50 in Y, but system macros will go to the same physical locations as if the G10 and G55 weren't present. So the G54 and G55 I added to system macros can be removed.

Does G28 also behave as expected? Using the offsets above, If I home in G55, then command G1 X0Y0, then command G54 the coordinates should display X50 Y50 and the physical location is the same as commanding G54 G28 G1 X50 Y50?

I'm curious how the G1 R1 works with pause, resume, and multiple work offsets. First a little background info. I am using a slicer for work that will only locate the part at the origin, but this is undesirable so I want to use work coordinate systems to offset the origin. I have to be able to switch back to machine coordinates when pausing and doing tool changes. I have been able to get this to work by using G10 L2 P2 X Y Z and then inserting G54 and G55 in my macros. For example, before the move to the tool change or pause position I put a G54, and on tpost or resume I put a G55. Is the G55 necessary? Will the G1 R1 return to the correct work coordinate system?
I'm not really sure I need to use more than one work coordinate system, but I am curious about the capabilities of this.

I want to share some of my experience tuning pressure advance. It was mentioned that you will need to recalibrate retraction.

I'm using a bowden tube setup and at higher speeds (100mm/s) I was missing material at the start of extrusion. Increasing prime amount would fix the higher speed problems but leave blobs at lower speeds (25mm/s). To resolve this I had to reduce the retraction distance. I ended up with retractions similar to a direct drive and no extra prime amount. I ended up with the following retract and pressure advance settings:

M207 S2.0 R0.0 F3600 T600
M572 D0 S0.3

This is with the following setup:
E3D Volcano, 0.4mm nozzle
550mm Capricorn XS Bowden tube
Bondtech QR Extruder
1.75mm Amazon Basics PETG

Extruder config settings per request: (these are not necessarily limits of the extruder)

M350 E32:32 ;microstepping
M92 E953:953 ;steps/mm
M906 E900:900 ;motor currents
M201 E1000:1000 ;accelerations
M203 E3600:3600 ;maximum speed
M566 E900:900 ;maximum jerk speed

Before Tuning these settings I was printing slower (50mm/s) with 6.5mm retraction distance.

@phaedrux I skimmed through that post, but was hoping there was something more user friendly like the linear advance gcode generator.

@deckingman Do you have any resources for tuning acceleration and jerk?

@gnydick said in Pressure advance calibration:

@Phaedrux the linear advance script does exactly the same thing as the pressure advance. The only difference is the layout.

The PA script stacks the layers so you look at the front of the model and look for the gradients to go away.

The LA script draws them side by side and you look for which line is most consistent in it's thickness.

That is the same test.

Is this script here somewhere?

I messed with pressure advance for a week and got nowhere. I tried that generator also, no luck. I noticed more change adjusting accel and jerk settings.
I noticed when increasing the pressure advance, when the line became more consistent the speed was slowed down. I used this speed to run a test with no pressure advance and got very similar results.. So I'm still at the start of pressure advance tuning..

@phaedrux I was wrong. They stay in the graph after reboot. Very useful. I'm using it to monitor my chamber heater, and control the heater with the chamber heater air temp.

Thanks, Will do! I noticed after adding the virtual heater it shows up under extras along with MCU. It seems as though I will need to add it to graph every time I connect to the interface. Is that true?

@dc42 Thanks! After reviewing M305 again I see virtual heaters numbered 100, 101, ....

I will add to my config

M305 P100 X154 T"K" ; Set thermocouple type K for heater 1

I love how versatile this is!

Thanks, I was able to remap 4 heater channels to drive the H-bridge. The only consequence I see, is that I seem to be maxed out on temperature readings now. I have two hotends, heated bed, and heated chamber. It seems that I should be able to read 4 more temperatures, but since I remapped the heaters to use PWM I can't monitor my extra thermocouples.

Is there a way to show these temperature readings on the temperature graph and keep the 4 pwm outputs? I don't have heaters for the extra thermocouples, they are just for science.

Hello. I have a Duet Wifi and Duex5 I am using for a new build. Aside from the stepper drivers I am using two hotends with thermocouples, heated build plate w/ thermistor, chamber heater with thermocouple and fan, 12V water pump, 24V power supply, and two 12v actuators with hbridge.

The hbridge is a l298n and requires 5v logic input, and looking for the best way to control it. On a similar build I remapped pins from the expansion header. I see that fan channels are selectable, but I'm not sure if I can use 5v and 12v at the same time. Also I'm not sure if I can use the servo connectors at the same time as 12V. I also saw there are 4 unused i/o pins, but not sure if those work while using the thermocouple boards.

Can anyone advise what the best route would be? I have everything hooked up and working except the hbridge logic pins. I would prefer to be able to pwm these pins if possible.

Thanks in advance!

I'm just guessing but are you reaching axis minimum before the axes stall out?

Check what you have for M208. I bet your stopping at the minimum and then setting that to your new home position.

Previously I used a h-bridge to control a dc motor forward and reverse. On a new machine I am planning to use the duetwifi with x5 expansion board to control everything. I'm interested in controlling these DC motors without the addition of an h-bridge. Is this possible? How can I accomplish this?

Thanks,
Jeff

I got this to work using heater channels 6 and 7 and the pins 1 and 2 on the header for GND and 5V. I setup the pins with
M307 H6 A-1 C-1 D-1
M307 H7 A-1 C-1 D-1

When I command M42 P6 S0 I read 3.3v to GND (pin 2) and when I command M42 P6 S255 they read 0V. Is this the expected behavior? Are pins 1 and 2 ok for 5V power?

I powered this with USB.

Thanks for the advice!

I picked up a H bridge, checked out the M42 command and the controlling IO pins link you provided.

What would be the prefered pins to use? I see heaters labeled pins 3-7 which look like 8, 13, 18, 23, and 28 on the expansion header. I don't see any labeled fan on the header though. I assume using a couple of the heater channels would be the way to go?

To implement this using heater 6 for direction and 7 for speed it would look something like this:
First disable the channels in config (I assume)
M307 H6 A-1 C-1 D-1
M307 H7 A-1 C-1 D-1

Then to extend the tool
M42 P6 S0
M42 P7 S255
G4 S1
M42 P7 S0

and to retract
M42 P6 S255
M42 P7 S255
G4 S1
M42 P7 S0

Am I on the right track?

I'm looking for some advice on using the duet to control a DC motor (6V 90mA). It's part of an actuator to raise and lower a second hotend, so it needs to reverse. My plan was to turn the motor on for a period and turn it off. Reverse motor direction to raise it. Both directions have hardstops.
Originally I planned to use a fan channel, which seemed simple to implement the gcode, but realized that they aren't bi-directional. Some research suggests to use a H-bridge. It looks like that would require two pins to control both directions.

I'm curious if there are any pins available other than the 3 fan channels. I'm also curious if an h bridge is the best option? If there are pins available are there any resources I can check out to see how to configure them?

Thanks!

@cbusillo:

What happens with an immediate move in the reverse direction? At 1000mm/s my printer would do a single move perfect. Back to back moves would cause it to skip steps.

hmm I will have to check. Here's a video I made 100 mm/s to 1000 mm/s. Each time around it increases speed 100 mm/s.

https://youtu.be/C9LVhPq3OWU

Quick update.

It seems that diagonal moves will be the most limited as they only use one motor. This is probably a torque limited speed rather than a processor speed limit.

After much testing and dropping my stepper currents to the rated 1500mA, I have reached a 1300mm/s max speed for diagonal moves. Interestingly enough it doesnt seem to care how high I set the acceleration. I've tested pure x moves, pure y moves and both diagonals at 1300mm/s with accelerations set up to 72000mm/s^2. I imagine compliance in the belts help out with this a bit.

This has been an interesting experiment!

Thanks after reducing to 32x I was able to hit 1000mm/s. Someone suggested using the 16x with interpolation. With this setting I have reached the maximum speeds for the travel and accelerations 2800mm/s for X and 2700mm/s for Y.

If I'm understanding it correctly when set to 16x it will use 256 and scale back as needed to keep step time above a certain value?