exceed max feed rate warning

[jimc]

with all these new settings that increase flowrate like infill width etc. it would be nice if there was an area where you could plug in your max feed rate then if you get within say 10-20% of that s3d would give a warning. sort of similar to the 1.2 height to width ratio warning. everyones extruder is different in how fast it can extrude a plastic before you end up with a jam. i have never had this happen with a standard .4 nozzle but when i jumped up to a .6 and try to do 175% infill width on a .35 layer height, thats a sure fire jam right there. there is just no way my hot end is gonna melt plastic that fast. the extruder gear is cookin at that point. it would save alot of failed prints if you got a warning during slicing that you were nearing the max mm/min or sec that your extruder will be pushing filament. this can be easily figured out as well by heating up the machine with the plastic of choice in it then in machine control panel keep bumping up the extruder feed rate and extrude 30-40 mm until you finally jam or get clicking. plug that value into your process and your done.

[dennisjm]

+1.
Exact same issue. First printer was a .4 nozzle. 2nd printer is .5 nozzle and on the 2nd I've had lots of problems needing to slow prints down because filament wasn't extruding up to the current speed settings.

On a very related note... how do you measure your max rate? Just use the control panel and try to extrude at different speeds until it doesn't work? I've tried to monitor the speed I could extrude without any clicking etc but then it's difficult to associate that speed with how fast the print will be extruding material.

[jimc]

+1.

I've tried to monitor the speed I could extrude without any clicking etc but then it's difficult to associate that speed with how fast the print will be extruding material.

yes thats exactly what im talkin about and why this warning would be great. we can use the jog panel to extrude until you get clicks or failures so you know your max. the problem is you dont know from your settings how fast that actually will be during a print. im sure the software could slice and find any point where that max feed rate would be exceeded. we could then go back, adjust print speed, infill width or whatever until you are within extrusion speeds that your printer can handle. right now after enough failed prints you just get a "feel" for where you should be. sometimes that works and sometimes it doesnt.

[JoeJ]

how many people actually know what their max extrusion rate is? I would have to do a lot of experimenting to figure that out, and I could use those results to summarize max flow multiplier and speed anyways, which is all you really need right now

[jimc]

very true. no one knows but i dont think it would take alot of experimenting other than to just heat it up and jog the extruder faster and faster until you find that out. its just hard to guess how fast your extruder is going to feed by just looking at your settings. its just and educated guess at this point which is fine but a little more fool proof if we knew. heck it wouldnt even need to be a warning. in the preview page near the build time or something just have it give a stat on the peak feed rate produced in the gcode. this would also be especially useful for flex filaments like ninjaflex.

[moraesgyn]

+1 today we limit the extruder speed on the firmware, but that affects the retract, we could have a advanced setting for extruder max extrusion speed and max retract. This way we would get rid of those zits when slow retracting.