Manual extrusion results in way too much material extruded



  • Hello...

    Is it normal for a manual extrusion (via the web interface) to extrude more material than requested? My Extruder is calibrated, by measuring the filament extruded at 100mm with the bowden detached from the hotend... as measured it is within .5mm when extruding 100mm. However, if extruding through the hotend at temp, I literally get 10x what is requested. If I tell it to extrude 1mm at 1mm/sec, I get nothing for a second or two, then 10mm will come out, at a nice steady pace. If I request 5mm, about 50mm will come out. At times the delay before it starts can be 3 or 4 seconds as well, but is usually a second or two, and very little delay if doing extrudes quickly one after another.

    It would be understandable if a little extra came out due to gravity and with a delay due to the bowden (I'm on a delta), but this seems a bit extreme to say the least, and the material extruded is not thinning out as if being stretched. While I have been fighting extrusion issues during prints, (I get symptoms of both under and over extrusion at the same time), but during a print, there is no way I am over extruding by 10x, so that is only happening on the manual extrude.

    So, normal or no? This is on a Rostock Max delta, using PLA at between 195 and 210c.

    Thanks

    -David



  • @kamacuras Are you sure that's what's happening. i.e when you request 100mm then 1,000mm goes into the extruder? Or are you looking at what comes out of the nozzle? 100mm of filament goes in to the extruder at 1.75mm diameter. So, if you extrude that 100mm out of your nozzle, the same volume comes out but because the nozzle is say 0.4mm diameter, then the length will be a lot more.



  • Slaps forehead.... yeah, more comes out of the nozzle, I was expecting the requested amount through the nozzle, but I completely ignored the fact that the filament is being squeezed, therefore stretched. So all good then.

    Thanks

    -David



  • @kamacuras That sounds like a "more caffeine required" moment.🙂 I get them now and again myself.


 

Looks like your connection to Duet3D was lost, please wait while we try to reconnect.