@Mike-1 I've only read the abstract and glanced through the rest, but it seems the article is about using an "instrumented extruder" fitted with a filament monitor and load cell to measure hot end pressure. As Duet don't make extruders, I'm not sure of the relevance of asking for the technique to be added to the firmware wish list.
Posts made by deckingman
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RE: Automatic calibration
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RE: Auto-resume after power failure - any con's or comments?
@gtrider said in Auto-resume after power failure - any con's or comments?
.........A big UPS is probably the best method.............
There is an alternative worth considering if you have a decently thick bed with a mains powered heater. That is to use a DC UPS. On my printer, if power should fail, the UPS cuts in and a couple of 9Ah batteries wired in series will keep the 24V supply and hence the machine running for many hours (about 4 hrs to reach 50% discharge) Naturally the bed will gradually cool and after a couple of hours or so, the part will likely fall off (because the bed heater is mains powered). But invariably any power outages I've seen have been much less than an hour so I've never (yet) lost a print.
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RE: variable to objects are pointers or something like that
@Tinchus said in variable to objects are pointers or something like that:
set global.filament = {move.extruders[0].filament}
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M701 S{global.filament}.........................but when M701 S{global.filamento} is executed I get and error saying Error: in file macro line 5: M701: non-empty string expected
It might just be a typo in your post but in your macro you refer to "global.filament" but later on when you describe the problem, you refer to "global.filamento" (an extra "o"). Does your actual macro refer to the correct global name?
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RE: acquistare duet o n ?
@Phaedrux As near as I can make out, compass dhm projects looks like an online retailer which has the duet logo on its web site, as well as bondtech, slice engineering and host of others. So I guess this is just an advertising plug.
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RE: PA issues with max flow rate testing
@mrwizzard said in PA issues with max flow rate testing:
.................. my E is plenty high....................
Can you quantify this? What is the actual value of your extruder jerk setting? As per my previous post, you can set it to what might appear to be a "silly high" value with no adverse effects but too low can be detrimental to PA
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RE: PA issues with max flow rate testing
@mrwizzard Most likely extruder jerk setting too low. You can set it "silly high" with no adverse effects but too low can interfere with things like PA.
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RE: Is there a way to run a 24v heater on a 12v duet2?
@brian said in Is there a way to run a 24v heater on a 12v duet2?:
@engikeneer Really? I thought when i bought the board i had a choice 12v or 24v. Wow, that changes everything. So would i just get a 24v power supply and everything would run?
Yes. As @Phaedrux has said, your motors will run better in that you could drive them faster before torque drops. If you have 12v fans you will need to set vfan jumpers accordingly or use buck converters. On no account use 12V heaters because the stated wattage will be 4 times higher if you "feed" them 24V. Sensors such as thermistors, end stops etc are unaffected by whichever Vin you use.
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RE: Rep Rap vs. Klipper
@gtrider The reason you aren't having problems with motors getting out of sync when cycling power maybe due to printing smallish parts in the centre of the bed. I frequently print large parts almost edge to edge on the build plate so bed levelling is far more critical.
The thing that most people forget, or don't know, is that levelling a bed makes it a plane which is level with a plane described by the attachment points of the lead screws. However, the gantry's often run on frame members which form another plane, separate to the bed and lead screw planes. With the best will in the world, it's practically impossible to build a machine whereby a plane described by the gantries is parallel with a plane described by the lead screw attachment points within (say) 0.1mm by eye. So some adjustment of the frame is usually necessary to get the gantry plane parallel with the levelled bed. This process is called tramming and is often overlooked.
Usually what happens next is that people probe all 4 corners of the bed or attempt a print, after the bed has been levelled, only to find that one or more corners appear to be high or low. They then assume that the bed must be distorted and resort to some sort of software compensation when on fact all that is required is to do the tramming process.
Having extensively used machines which required software compensation and those that do not, I know which I prefer. As well as the time taken to run the software compensation, one must also take into account the time and filament wasted if the compensation is not regularly run and prints fail.
I agree with your comments about a separate SBC. -
RE: Rep Rap vs. Klipper
@oliof said in Rep Rap vs. Klipper:
and software always wins over hardware.
I agree with everything you say apart from that one final sentence.
Silk purses and Sow's ears come to mind
A couple of examples. Multi point bed leveling using multiple lead screws. It isn't difficult to build a bed that is level and stays that way without any adjustment, driven by 3 screws, a single motor and continuous belt. Yet on the basis that "software is always better than hardware" people continue to adopt and use multiple screws and let software take care of things. Then whenever power is cycled the motors jump in different directions by up to 4 whole steps, meaning that the bed leveling procedure has to be run every time the machine is turned on, which is just a waste of time.
It also isn't difficult to build a bed which is flat, tram, and stays that way. Yet people insist on using (software) mesh compensation instead. The real crazy ones buy expensive tooling plate then because they don't know how or are too lazy to adjust the gantries such that they are tram with the bed, still use mesh compensation. A quick glance at some of the forum posts will reveal a plethora of issues that people have getting the software to work. Even if they manage to get it working, it is seldom consistent because the mechanical issues that it's supposed to compensate for can be variable. So the mesh has to be redefined. Having to constantly adjust the Z height while printing a single layer, also leads to unnecessary wear on the lead screws.
It took my less that 2 hours to get my bed flat, level and tram within less than 0.03mm over the entire 400mm x 400mm area and I've never had cause to make any adjustments since I built the machine. From what I've seem from posts on this forum, the "software always wins over hardware approach" would take up much more time over the life of the machine.
IMO, if you build a machine that is mechanically crap, it'll always be a crap machine, regardless of the software (or indeed the computing power of the control boards).
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RE: Measuring PWM output and duty cycle
@3DPMicro The Duet MOSFETS usually switch the gnd side not the V+ side. So I'd guess your scope would see something if you connect it to the gnd on the connector that you use for the spindle rather than some other gnd.
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RE: `Duet 6HC Output 3 output always on
Having read your post again, I think you are misunderstanding how PWM works. The PWM value sets the on time between zero and either 1.0 or zero and 255. In either case, zero is fully off, and 1.0 or 255 ate fully on using a different scale. Think of the PWM value as being the on/off ratio. The frequency is the time between one complete on/off cycle and the next. So for the purpose of switching a solenoid between fully on and fully off, the PWM frequency is irrelevant. By way of illustration, if the frequency was set to 10 Hz, there would be 10 on/off cycles per second. But if the PWM value is set to 100% then the MOSFET will be fully on for each of those 10 cycles.
Having said all that, I suspect the firmware code might always expect the PWM frequency to be greater than zero. So it could just be that using a Q value of zero is causing the issue you are experiencing. I suggest you try again using a non zero Q value. -
RE: `Duet 6HC Output 3 output always on
@Duet_Science_Application The MOSFETs switch the negative (gnd) side so there will always be voltage present on the positive side. Are you measuring the voltage between positive and out3 gnd or some other gnd?
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RE: Moving several axes simultaneously - XYZ and UVW
......or another approach is to post process the sliced gcode file to add the additional axes moves. That's what I used to do when I ran a CoreXYUVAB.
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RE: A question for Deckingman (ian)
@tierod Yes, on a CNC machine, swarf or debris could be an issue so maybe not such a good idea.
Maybe the arrangement I used before changing to a slotted opto switch might work for you. This was a "normal" micro switch mounted on an arm that could pivot against a spring. So to get the bed somewhere close to the nozzle at high speed, I did a series of 100mm moves, and checked the state of the switch after each move. If the switch was open, I'd do another fast move. If the switch was closed, I'd do the slow homing using the nozzle as described earlier.
So effectively the carriage could continue to travel some distance after the switch triggered without anything crashing. The arm holding the micro switch would just pivot against it's spring -
RE: A question for Deckingman (ian)
@tierod I'm currently 10,000 miles away from my printer and PC so have limited access to files and images. However, I don't think my Z homing switch would suit your application. Essentially I use the nozzle as a probe. So the hot end is mounted on a kinematic pivot which allows some movement in Z but none in X or Y. It's held against the stop with springs and the stop itself is a brass plate which abuts a brass bolt. By connecting wires to the plate and bolt, this makes both an electrical switch as well as a physical stop. When homing Z , as soon as the bed touches the nozzle, the hot end pivots and the electrical contact is broken. In practice, the physical movement is immeasurably small.
What might suit your application better would be my fast homing switch which is a "flag" made from thin sheet aluminium which passes through a slotted opto switch. The idea is that the initial fast homing moves the bed in series of 100mm moves and repeats until the opto switch triggers. This gets the bed somewhere close to the nozzle before the slow homing using the brass plates. -
RE: re-naming tool change macros
@mikeabuilder Not sure if this answers your questions but it might help. When I was using a multi material hot end, I used variables and meta commands to create "universal" tool change macros named "toolFree","toolPre", and "toolPost". Then every tpre(n) had the same one and only command M98 P "toolPre", every tfree(n) called "toolFree" etc.
It worked fine and nothing got broken.
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RE: Proper gcode for multiple drives and extruders
@yoshimitsuspeed I do likewise with setting different values for each filament type by using the slicer custom gcode. I tend to use a separate line for each extruder even when a colon separator is permissable as it reduces the possibility of errors and ambiguity. I also find that using global variables and a macro is a great help.
I agree that the use of "E" and "D" can be confusing. But afaik, "E" is only used where a command has values for both axes and extruders whilst "D" is only used for commands that only apply to extruders, so that is a good way to remember.
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RE: Pressure Advance smooth time
@Kiolia If I understand correctly, this all hinges on the assumption that PA as implemented in RRF uses an instant extruder feed rate change. How sound is that assumption and does it respect or ignore the jerk value set by M566? If not an instantaneous feed rate change (which in practice is impossible) then does the extruder acceleration under PA conditions respect or ignore the maximum acceleration set by M201? Do we know for sure that RRF uses the same PA algorithm as Klipper?