Extrusion multiplier with bondtech

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3dlabs
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Joined: Sun Dec 17, 2017 6:10 pm

Extrusion multiplier with bondtech

Postby 3dlabs » Wed Feb 07, 2018 9:26 pm

Does anyone with the bondtech upgrade find that they still need an extrusion multiplier of 0.94 for Raise 3D premium PLA, or was that a compensation for the stock hardware?

Jetguy
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Re: Extrusion multiplier with bondtech

Postby Jetguy » Thu Feb 08, 2018 3:49 pm

Technically, it's a compensation for a series of values.
Filament diameter actual VS what is input into the slicer, flowrate multipliers throughout the profile, and then firmware based final modification of the value via flowrate (either LCD or in the gcode M221) all modify final extrusion volume.

Because filament diameter is often completely ignored or people just aren't even aware of measuring actual and entering it into the slicer and that value is also not directly in the slicing profile, we have a situation where the default 1.75mm that is in Ideamaker is highly unliikely to match typical industry real world values of around 1.82mm for many filaments (Esun is often around 1.82, 1.83).
The 94 is also a telltale number that is borrowed from old school makerbot. What happened there is ABS and PLA bite differently into the makerbot hobbed drive gear and resulted in different steps per mm even though the motor rotated the same distance. As such, ABS was kind of the first filament used back circa 2010, and PLA was new and experimental. So PLA was reduced filament flowrate to make up for the drive gear as you suggested (ABS would be 100% Flowrate as the baseline) Drive gears and mechanisms are slightly different between a 2010 makerBot and 2016 designed Raise3D, so using a canned default percentage assumed to be that classic ABS VS PLA and then borrowed and stuck into Ideamaker shows just a lack of understanding of the entire subject if we are honest. It's blatent copying without even understanding why or what it meant. What are the odds that 94% is dead on the money resulting in PLA being exactly 100mm moved per 100mm commanded in gcode, and ABS with 100% flowrate multipler being also dead on 100mm gets 100mm? See what i'm saying here?

But back to your question because you asked something very, very specific, "still need an extrusion multiplier of 0.94 for Raise 3D premium PLA". The one thing said by Raise 3D is that their Premium PLA is much higher tolerance and much closer and more accurate to 1.75mm actual.

So I know that may be muddying the answer but here's the why and logic.
"with the bondtech upgrade find that they still need an extrusion multiplier of 0.94 "
I would tell you know, the first thing is, I would start with 100%.
I would then measure actual filament diameter, enter that into the slicer, ensure the printer LCD is showing 100% flowrate.
I would also do a real world E-steps calibration using the filament you are most likely to use daily and using the control panel after a preheat, mark a line on the filament 100mm above the extruder, then command 10 times, the 10mm feed filament jog command and measure how far off from exactly 100mm was moved. Again, giant assumption here, you ensure before the test the LCD said 100% flowrate, you entered the Bondtech recommended steps per mm into the hardware section of the LCD screen.
Then again, that test, you can make a decision to either use flowrate and compensate, or use steps per mm and compensate/calibrate.

Then you print a couple of test cubes and other objects after getting the basic firmware doing what it's supposed to do (100mm commanded filament gets you real world 100mm on the nail extruded filament) you find the flowrate (also assuming you measured and entered the exact filament diameter.

I highly doubt you end up at a 94%.

Jetguy
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Location: In a van, down by the river

Re: Extrusion multiplier with bondtech

Postby Jetguy » Thu Feb 08, 2018 4:01 pm

Also, again, you said this "was that a compensation for the stock hardware?".
I'm not going to tell you that steps per mm on the stock feeder was dead on. I just cannot say or do that and my printers have all been upgraded so i cannot go back and 100% validate this.
I can say, Raise 3D makes all 3, software (thus default profiles and settings), the printer firmware default settings and the hardware, and last, the very filament in question. So yes, as a tuned set, Raise 3D premium PLA, a Raise 3D printer in totally stock configuration with stock settings, the default Raise 3D ideamaker profile prints well out of the box.

To define what error existed and how one of multiple values interacted (94% flowrate default in a profile) for hardware (steps per mm and also technically filament actual diameter vs slicer diameter) are hardware values. 94% could compensate for undersized slicer filament value and oversized steps per mm. The 3 factors all work together. I will say this, a 1% length value error (steps per mm) VS a diameter error are not the same end result. Diameter is area of the filament multiplied by length of a given segment to make a cylinder of volume. So a 1% error in diameter coupled with a 1% error in length can add up. 94% flowrate is saying somewhere else, we have 6% total error in volume between steps per mm and diameter vs what the slicer was told error.

Jetguy
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Location: In a van, down by the river

Re: Extrusion multiplier with bondtech

Postby Jetguy » Thu Feb 08, 2018 5:09 pm

Also, because you might want to use other slicers, Raise 3D gcode produced by Ideamaker leaving a 94% active current flowrate could then affect you printing from another slicer (say S3D) that assumed a firmware value of 100% normal flowrate, but because you previously printed with a 94% flowrate gcode profile from ideamaker that left the machine active memory state with a 94% gcode commanded flowrate, and your S3D profile and thus gcode did not include a gcode command to purposely set rather than assuming the flowrate was 100%

Again, what I'm saying is, a flowrate gcode command, it absolutely can backfire on you.
It also bucks the convention that gcode is faithfully to the letter followed by the machine firmware and hardware--- that's what interferes when we start talking other slicers.

So to be direct, no, I would intentionally change my Flowrate default to 100% in all my ideamaker profiles if I spent the time to upgrade and calibrate my printer with a brand new extruder. I would examine produced gcode and ensure it did not set a default 94% flowrate. I would go the extra step and edit my starting gcode to include an M221 S100 to ensure I had no assumptions on flowrate going into a print job from any slicer.

3dlabs
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Joined: Sun Dec 17, 2017 6:10 pm

Re: Extrusion multiplier with bondtech

Postby 3dlabs » Thu Feb 08, 2018 7:51 pm

So let me ask you what happens in this scenario:

- you set a global flow rate of 94% (for hypothetical example purposes) in ideamaker
- then you set the "Top solid fill flowrate" setting in the infill tab to say 102%

Is that 102% flowrate overriding the global 94% temporarily for those layers, or is that 102% of that 94% rendering it closer to 96% for those layers?

Jetguy
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Location: In a van, down by the river

Re: Extrusion multiplier with bondtech

Postby Jetguy » Thu Feb 08, 2018 8:45 pm

Global flowrate puts a command at the start of the print to set the firmware reading all gcode to 94%
When you edit a layer or feature specific item in the slicing profile, that edits the final length of E values in the code in the print file.

Again, what is going wrong here is that by setting a flowrate in firmware using M221, you are breaking gcode length = physical length actually extruded. For the purposes of tuning and especially printing from 2 different softwares and at least one of them expecting 100% normal flowrate. This just causes massive confusion and more problems than it's worth.

Jetguy
Posts: 2697
Joined: Tue Mar 22, 2016 1:40 am
Location: In a van, down by the river

Re: Extrusion multiplier with bondtech

Postby Jetguy » Thu Feb 08, 2018 8:56 pm

Again, solid top flowrate, those segments in the gcode print file will be modified before the file is written to 102% of the ideal volumetric value.
Then the 94% truly is "global" because of how and where it gets set. It adds the M221 S94 command to the start of the print file, and that in turn makes the firmware read every single line of E value in gcode and reduce it by 6% when sending the stepper driver step pulses.

That is the fundamental difference between Ideamaker and most other slicers.
Example is, Simplify 3D and others you absolutely also have a global flowrate and individual slicing specific ones. However, the gcode produced is very different. Again, normal slicers (AKA everyone else but ideamaker) they modify the final e values in the produced gcode and the assumption is firmware based flowrate modifier is always set to 100%.
Ideamaker in the case of the global flowrate- adds a gcode command and makes the firmware do it, but is really mixed in that individual layer and feature flowrates modify the gcode.

Further, as stated, if you print an ideamaker print file that just happens to have the default of 94% flowrate, the end commands do not set it back in firmware to 100% for the next print. At the same time, the default starting gcode in a typical Simplify 3D and other slicers does not inlcude the M221 command to set flowrate to 100% and yet the entire system is based on that assumption.

See how quickly this becomes a total disaster? If you start the printer from power off, it defaults to 100% flowrate in firmware. If you then print right now a default Ideamaker N series profile just as provided with no edits, it will set the printer firmware to 94% flowrate. If you then do not power cycle the printer to reset it to factory defaults or manually via the LCD set flowrate to 100% or fail to add this M221 S100 to the starting gcode of your other slicer other than ideamaker, all the sudden one print could under extrude because you printed an ideamaker file beforehand, or your cycle it overnight, and start the exact same Simplify 3D file the next day and it prints normally because again, it expected 100% firmware flowrate and because the printer started default and was not set by a file to 94% it prints 100% flowrate.

3dlabs
Posts: 17
Joined: Sun Dec 17, 2017 6:10 pm

Re: Extrusion multiplier with bondtech

Postby 3dlabs » Thu Feb 08, 2018 9:50 pm

My simplify 3d profile has the following in the startup script by default and I've never had a problem with going back and forth between slicers:

M221 T0 S100


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