Duet WiFi firmware new feature priorities

mhackney

Wow, that's a long and great list!

1 C Predictive temperature control
2 O Support for restore points
3 L Faster file upload speed
4 M Babystepping - if implanted with a usable UI
5 B Multi-threaded web server,

and some comments:

re: config_override.g - smoothieware uses this and it did nothing but drive me crazy! I frequently had unexpected results that turned out to be override settings. If you do go down this path, making it editable in DWC like the config.g is would go a long way to help.

SSH would be ideal over telnet but telnet is fine for me. I only run on my internal network so security is not a huge concern. But I can see it being important in an educational and industrial situation.

ROBUST DWC connections - I know huge progress has been made on this this year but it can still improve.

mhackney

Here's a new request: an option to perform both the auto calibration (G30 Sx) AND return the results the way S-1 does.

franknitty69

1 - predictive temp control
2 - grid based bed comp
3 - restore points
4 - dynamically varying microstepping
5 - Support for three independently-controlled Z motors

CodonExe

My vote is:

C. Predictive temperature control
J. Dynamically-varying microstepping
I. Faster microstepping
M. Babystepping
E. Support for an external SD card socket

deckingman

Just thought of a "anything else".

Some sort of running total of print time to date. A sort of "hour meter", or "mileometer". It would be useful for setting up maintenance schedules\reminders. Like "lubricate guides" every x number of hours or "change belts" every y hundred hours". I guess this is more a web interface thing, as it would need to be running total of when the printer is actually printing rather than power on time. Just a thought…....

bot

Oh yes, the hourmeter would be a very very nice feature. It could be nice to know individual axes' travel distances, as well as print hours, total powered up hours (for motors) etc.

RichRap3D

Very nice list, choices, choices…

My vote would be -

- F. Support for multiple independent X carriages.
- A. Higher stepper motor current (above 2A)
- P. Control over which access point
- N. Support for driving RC servos - But do the HW on the expansion header (shield) with a +5V reg + I/O etc.
- R. Support to compensate for axis hysteresis

In my first week of using DuetWifi I would have voted for E. Support for an external SD card socket, but now it's almost not even something I would think about, and it's annoying that other 3D printers are still using a slow external card…

Best Regards,

Rich.

Pumlux

I think this is my preference of order.

C. Predictive temperature control.
H. Grid-based bed compensation,
J. Dynamically-varying microstepping
O. Support for restore points.
G. Support for three independently-controlled Z motors

I read DC42 start post that way, the other topics will
not be dropped, just come later.

One suggestion from my side ( I believe the topic
was already discussed in some thread(s) on the RepRap forum)

What about having a dedicated button (pin) for pausing
the print (similar the pause Web Button) ?

Sometimes I have see someting strange during the print
and would like to pause. The Webbutton is to slow to reach
and a power off (like an emergency stop button)
ruins the print.

bot

The PanelDue offers exactly this pause button. I personally would never run a duet printer without a paneldue. It's a much more reliable and fast means of controlling the printer than the web interface. Keep in mind, the pause command does wait for the last gcode command to finish executing (or maybe even the whole queue).

BMMal

I just pre-ordered a board. One feature I want to request (if it doesn't exist already) is an extruder advance (aka JKN, Linear Advance, etc) to help compensate for hysteresis in bowden systems. My machine has some very long bowden tubes and enabling this (unfinished) feature in Marlin's RC Bug fix branch made a noticeable difference on corners and top infill quality.

dc42

@BMMal:

I just pre-ordered a board. One feature I want to request (if it doesn't exist already) is an extruder advance (aka JKN, Linear Advance, etc) to help compensate for hysteresis in bowden systems. My machine has some very long bowden tubes and enabling this (unfinished) feature in Marlin's RC Bug fix branch made a noticeable difference on corners and top infill quality.

Good news for you. RepRapFirmware has supported extruder pressure advance for around 18 months. See
http://reprap.org/wiki/Gcodes#M572:_Set_or_report_extruder_pressure_advance

BMMal

@dc42:

@BMMal:

I just pre-ordered a board. One feature I want to request (if it doesn't exist already) is an extruder advance (aka JKN, Linear Advance, etc) to help compensate for hysteresis in bowden systems. My machine has some very long bowden tubes and enabling this (unfinished) feature in Marlin's RC Bug fix branch made a noticeable difference on corners and top infill quality.

Good news for you. RepRapFirmware has supported extruder pressure advance for around 18 months. See
http://reprap.org/wiki/Gcodes#M572:_Set_or_report_extruder_pressure_advance

Excellent news! And it's per extruder, even better! Can't wait to get my hands on it!

PRZ

My own list for a printer:
1/ H grid-compensation
2/ C temp control with auto-tune
3/ D Simple panel
There was on forum someone asking for an odometer (recording filament consumption) and printing hour counter. That shall not be high priority, but that may be a nice to have.
The Duet WiFi having higher current capability, it can be possible to handle a CNC, but there is need to implement a few more G-Code

M0/M1 stop/start for tool change
M3/M5 start/stop spindle
M8/M9 Coolant on/off
M10/M11 : Vacuum (for part maintaining) - lower priority
Sn : spindle speed
Heaters output can be used to command SSR or to make a PWM for spindle speed control.
A 'standard' mapping shall be decided, e.g. E0 heater -> spindle on/off E1 heater -> coolant on/off , Bed heater -> Vacuum pump, Fan0 for spindle speed control.

Shapeoko is listing the G-code it is using here http://www.shapeoko.com/wiki/index.php/G-Code

Aussiephil

@PRZ:

There was on forum someone asking for an odometer (recording filament consumption) and printing hour counter. That shall not be high priority, but that may be a nice to have.

Hey that was me :), sort of forgotten about it but yes it would be good to have but low on the list

Second the CNC stuff….. that will be my next big project.

dc42

It's time to summarize which firmware features you want most. I allocated 5 points to your first choices, 4 points to your second choices usw. and added them up.

By far the most wanted feature is predictive temperature control with auto tuning (51 points). After that comes dynamic microstep generation (30), grid-based bed compensation (27), restore points (24), faster microstepping (23), and higher motor current (21) and babystepping (18).

I already implemented faster microstep generation and released it in firmware 1.14.

Dynamic microstepping and higher motor current are related, because they both involve the SPI interface ti the stepper drivers. So I plan to implement them together. This leads me to the following provisional plan:

#1 Predictive temperature control with auto calibration

#2 Higher motor current and dynamic microstepping

#3 Grid-based bed compensation

#4 Restore points

We also expect to have OEM customers for the Duet WiFi so I will be taking their views into account too.

bgkdavis

Really have to ask, but what on earth is 'predictive temperature control' are you talking about Feed forward or heuristic control?… both I would consider to be a poor replacement for PID.

The problem with PID control is tuning and most people who talk about tuning of PID rarely explain that the tuning methodology changes with the form of the PID algorithms (and there are many forms)

How about replacing the existing PID algorithm with an auto tune algorithm?

dc42

It's feedforward control. Why would you consider it to be a poor replacement for PID? PID is OK at correcting for small changes in the status quo, but it's fairly useless at achieving the target temperature in the first place.

bot

What exactly about it are you trying to improve? I don't think I've ever been unable to tune a PID adequately enough for it to have no ill-effect on prints.

One thing that would be nice for an alternate to PID, is for it to be able to set temperatures for times in the future. For example, have an idle heater heated up at the precise moment it is needed, rather than having to wait. It would account for the heatup (and cooldown) times and time the signals appropriately to have the heater ready or not when it is needed or not. This would be useful in the case of a stationary idle extruder.

Great_Thark

b c j o h in no particular order

RCarlyle

Feed-forward temp control (or more accurately "model-based" control) doesn't really get the average user anything (except maybe 10-20 second faster stabilized preheat time) but it is very valuable for two extreme usage cases:
1) Very high-speed printing. Large changes in filament melt power (and I do mean LARGE, like with a Volcano changing from slow perimeters to fast infill)) cause massive temp fluctuation that can trigger firmware heater safety cutoffs and affect print quality.
2) Very light-weight hot ends. When the temp sensing time lag and/or heater power are large relative to the heat capacity of the hot end, feedback control algorithms like PID can become mathematically incapable of outputting a stable temperature with acceptable settling time. Basically if your process gain or sensor time constant is too large, PID is a bad control scheme.

The PID autotune technique used by all the other 3d printer firmwares (specifically, the relay method with old-school Ziegler Nichols parameters in Marlin, Repetier, Smoothie, etc) really is NOT very effective. It outputs mediocre tuning values. The fact that hot ends heat up much faster than they cool down violates the mathematical assumptions going into the relay autotuning method. You can improve the auto-tune algorithm with some tweaks, which Redeem has recently implemented, but at a certain point you have to ask why you're using increasingly complex implementations of PID – a super-generic control scheme that is ideal for un-modeled processes with unknown disturbance inputs -- rather than making a bespoke control algorithm that takes advantage of the well-known physics we're dealing with here.

3D printer hot end control is a VERY good candidate for a feed-forward model. Almost all heat flux can be accounted for with three terms: heater power, heat losses due to temp difference between the hot end and ambient, and heat leaving the hot end in the melted filament. All of these can be auto-calibrated without too much difficulty. Then you add in a minimal PID-style "I" feedback loop to correct any residual model error, and bob's your uncle -- super stable temp control for a wider range of hardware and print conditions.