Posts made by ben_van

@deckingman said in New firmware 2.03RC2 available:

@ben_van Fascinating stuff. Out of curiosity, are you using "standard" 1.75mm diameter filament? I've always thought that to extrude tiny amounts of filament, the way forward is to use something that has a much smaller cross sectional area to start with.

I didn't mention that this machine doesn't use filaments. It uses a tightly focused laser (we can easily change the dot size) to solidify tissue-like gels that are synthesised with certain proteins etc. It is somewhat similar to a traditional SLA machine but with differences in the layering methods.
Extruding filaments to that size would be cool though, and i definitely agree with you there. Other than there not being much of a demand for printing such small things, maybe filaments with such small diameters would just be too fragile..

@jv43 said in New firmware 2.03RC2 available:

@ben_van looks interesting, but what the heck is that?

It is a generic 2D scaffold used for cell culture. Tissue engineering is not my field of expertise but for the people I am working with it is. This is just a test print to show we are working on a scale smaller than that of a stem cell, and about the size of a T-cell.
Cells are present while this structure is printed and are encapsulated inside the bio-compatible gel, where they then grow/multiply inside it, as it is like food for them. I like to think of it like bread crumbs, where we can coax the cells to grow and develop in a very controlled manner.
Whilst i can't dive into many specifics of how everything works until something is published, I can say that we have been getting some very good results
The benefit of using all open source software is once the groundwork is in place for this method, we can easily use readily available 3D printer slicers to make any micro 3D structure straight from a CAD model, and hopefully be able to provide this to people wanting to experiment without the $100k+ pricetag that comes with anything with the word 'bio' in it.

@dc42 said in New firmware 2.03RC2 available:

@ben_van said in New firmware 2.03RC2 available:

As for the M350 extruder microstepping, I will change to the following:
M350 X256 Y256 Z256 E256 I0

We don't recommend using native x256 microstepping. You will be limited to low speeds if you do, because generating the step pulses will use up too much processor time. It may be OK for a CNC machine, but not for a 3D printer.

I understand the computational expense of doing this.. going fast is the last thing i want Most of the stuff made with this machine is seldom larger than 1mm, at speeds less than 50mm/min, and we have never experienced speed issues being limited by the CPU. This doesn't solve the G0 problem though..
To give you an idea of why this matters, here is a sample pic of one of the things we can do with this machine + duet . It's too small to see properly with the naked eye.

@wilriker Ah thankyou for pointing this out. The G10 for tool 1 was a typo from copy/paste. I guess I never noticed since i don't have any heaters bound to the tool anyway. As for the M350 extruder microstepping, I will change to the following:
M350 X256 Y256 Z256 E256 I0
Not sure why I didn't have it written like that before..

@dc42
Just did a few tests..
Everything works as expected for G0 moves if the feedrate set in M203 is higher than 60mm/min. If I set the max feedrate lower than 60mm/min in M203 for any axes, G0 moves will still request a speed of 60mm/min.
Setup:

• Duet 2 Wifi
• Web control 2.0.0-RC6
• Wifi server 1.23
• PanelDue 7.0i 1.23.2

Config.g is as follows:

; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

; Network
M550 P ; Set machine name
M552 S1 ; Enable network
M587 S"" P"" ; Configure access point. You can delete this line once connected
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards

M350 X256 Y256 Z256 I0 ; Configure microstepping without interpolation
M350 E64 I1 ; Configure microstepping with interpolation
M92 X3769 Y2094 Z256000 E53 ; Set steps per mm //// XY:mm, Z:mm, E:ul

M566 X45 Y45 Z3 E200 ; Set maximum instantaneous speed changes (mm/min)
M203 X2500 Y2500 Z20 E10000 I1 ; Set maximum speeds (mm/min), and I (minimum speed)
M201 X2000 Y2000 Z10 E2000 ; Set accelerations (mm/s^2)
M906 X500 Y500 Z500 E500 I75 ; Set motor currents (mA) and motor idle factor in per cent
M84 S60 ; Set idle timeout

; Axis Limits
M208 X-75 Y-48 Z-30 S1 ; Set axis minima
M208 X0 Y0 Z0 S0 ;Set axis maxima

; Heaters
M140 H0 ; heater 0 is the bed
M305 P0 S"Vessel heater" T100000 B3950 R4700 C0;
M307 H0 A26.6 C73.9 D1.0 B0 S0.2 V12.6 ; set process parameters for heater 1, use PID, and limit heater 1 PWM to 20%
M143 H0 S45 ; Set temperature limit for heater 0 to 50C

; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S0.5 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S0.5 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

; Automatic saving after power loss is not enabled

; Custom settings

M106 P0 I-1 ; Disable the Fan
M106 P2 I-1 ; Disable the Fan
M452 P22 R255 F8000 ; Set the printer into Laser mode P(Fan) R(Max power value for S command with M3) F(PWM frequency used)
M564 S1 H1 ; H0 allow movement before homing, S1 limit motion between axis boundaries
M574 X2 Y1 Z2 S0 ; Set active low endstops (for some reason never set z properly in configuration

; Tools
M558 P0; disable the z probe
M563 P0 S"Laser"
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C
G10 P0 X0 Y0;

M563 P1 S"Camera"
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C
G10 P1 X-1 Y-0.6;

M563 P2 D0 S"Extruder" ; Define tool 2
G10 P2 R0 S0 ; Set initial tool 2 active and standby temperatures to 0C
G10 P2 X0 Y0 ; Set tool 2 axis offsets

T0 ; Select tool 0 (laser) on startup

@dc42 said in New firmware 2.03RC2 available:

@ben_van said in New firmware 2.03RC2 available:

Thank you for adding the option to set the minimum movement speed! Now i can work all axes in mm.. However it seems like there is also a minimum limit of 1mm/s applied to G0 moves as well? In my config file I set this:

M203 X2500 Y2500 Z20 E10000 I1

If I send G1 Z5 F20; the commanded speed is correct.
If I send G0 Z5; The max feedrate set in M203 is not honoured and it commands 1mm/s or F60.
This doesn't really bother me except that all of the motion buttons on the PanelDue and Webcontrol send a G0.. Or am I missing something??

Are you running the machine in CNC mode (using M453) or in the default FDM mode? In CNC mode, G0 should use the maximum feed rate. In FDM mode, it uses the same feed rate as G1 commands.

I am running the machine in laser mode (M452). Previously when i was using older firmware, and had the Z axis in steps per micron, G0 moves would take the max feedrate set in M203. They do also on this release, however only for the X and Y axis, not Z.

Thank you for adding the option to set the minimum movement speed! Now i can work all axes in mm.. However it seems like there is also a minimum limit of 1mm/s applied to G0 moves as well? In my config file I set this:

M203 X2500 Y2500 Z20 E10000 I1

If I send G1 Z5 F20; the commanded speed is correct.
If I send G0 Z5; The max feedrate set in M203 is not honoured and it commands 1mm/s or F60.
This doesn't really bother me except that all of the motion buttons on the PanelDue and Webcontrol send a G0.. Or am I missing something??

@dc42
Yes i completely understand your reasoning for having the limitations, and would be perfectly fine if my setup/needs were not so abnormal..
I need to go as slow as 1mm/min (0.0167mm/sec)

Thankyou!!

@fcwilt
Yes.. But coding is definitely not my strong point. I was hoping someone here could point me in the right direction if it comes to recompiling some custom code

Hi,

I just mean that large motions of the stepper motor produce very small motions of the Z platform, through planetary gears (1 rotation of stepper = 200micron)
I do not mean to say that the gears are heavy in mass, or that they are hard to turn...

Hey thanks for your suggestions
Yes, I'm simply just hitting the minimum speed floor. Anything less than an F30 the firmware will ignore..

I don't understand how switching the microstepping would change anything other than the number of step pulses required to achieve the same motion?..

I could change the gearing from the stepper motor to the focus on the Z axis however I can't change the gearing in the internals of the microscope whithout major work.. Which is the issue. Regardless of other gearing those internal gears will spin at the same speed to translate a 0.5mm/sec move to the microscope stage and spin too fast for comfort.

I have been able to achieve the slow speeds I need so I know the duet is definitely capable, it just makes writing gcode very non conventional.

Physically I have 16000steps/mm but I have set it up as 16steps/mm in the firmware. So now when I want to physically move 1mm in the z axis, my gcode would look like (G1 Z1000 F1000) as feeds and speeds are now in microns.
What I really want to do is simply say G1 Z1 F1, but the F1 command will be ignored and I'll get an F30 instead..

Re: Unable to get slow G1 + English/metric questions

Just wondering if anything to allow movements slower than 0.5mm/sec has been changed in the latest firmware release (2.02)?
I am currently running my duet 2 Wifi in laser mode on a modified microscope where very fine/precise movements are necessary. The main issue is the heavy gearing on the Z axis (~16000 steps/mm with 1/16th micro stepping) making even 0.5mm/sec movements way too fast for the system.

To solve this for the time i have converted the Z axis steps/mm to really be steps/micron, however this doesn't make previewing gcode very nice and requires fixing any gcode i didnt generate myself for all Z moves/feeds to also be in microns.

I would really like all the gcode to be in mm, and still allow moves as slow as 1mm/min, if this can easily be achieved?

Any help is appreciated.
Thanks!!