Precise Extruder Steps Per MM

[Jimustanguitar]

If you need to calibrate your extruder's steps per mm still, try this trick. Cut off 2 or 3 feet of filament to work with and lay it out on top of something flat. You can put a book or something like that on each end to hold it straight. Use your calipers to measure out 100mm segments, and when you need to make a mark, use a razorblade and press a small nick in the filament. Then draw a line over the cut with a sharpie and wipe it off. The marker's ink will wick into the cut and stay there after wiping the ink off the surface. This will give you a very sharp and easy to identify mark to gauge your extruder's feed with.

Detach the bowden tube from the extruder and start feeding in the piece that you marked. Line up the first mark (make sure you are watching the filament before it goes through the extruder, not after) I aligned my mark with the clear plastic guide on the bottom. Extrude about 90mm. Then click it 1mm at a time (while counting) to see if the 100mm mark lines up exactly where the first one started. If not, feed it 1mm at a time until it does. Then do some division and apply the result to your steps per mm setting. Do this a few times until it is too close to tell anymore. Then you can feed 200mm or 300mm through it at once and see where that lines up to make a finer adjustment.

Note: several people have commented that they like to break up the 100mm feed into multiple varying lengths that equal 100. Feel free to do this if you think it will give you a more accurate result.

[wildideas1]

Ok I see that no one has ever asked this but are you extruding with hot end or extruder cold with tip off unit like calibrating the h1

[Jimustanguitar]

I've unhooked the bowden tube, so I'm not going through the hotend at all. The point of this is only to measure the amount being fed into the extruder. Kind of an infeed calibration.

The next step is tuning your extrusion multiplier, which is like your outfeed calibration.