Doing a cold extrusion without the hotend installed is improper as it neglects the viscosity of the filament. There’s a reason the tutorial linked by @CNC-Maker above suggests using a feed rate of 50 - because that mimics the feedrate during actual use (without being terribly slow), for a comparable amount of backpressure in the nozzle.
Now that you have calibrated cold, when you go to use it it will extrude slightly less than expected due to the pressure in the nozzle causing a small amount of slippage on the drive gear. This effect will be less pronounced at slow print speeds, and more pronounced at high print speeds.
This effect is the same effect that linear advance calibration deals with, as filament is slightly springy, causing extrusion at the nozzle to be coupled with drive pressure at the gear through the ‘springiness’ of the filament.
Good call @sdj544; I ended up running my new calibration runs @ 75 mm/min with great results, admittedly it was pretty slow (1min15sec), so hopefully people have the patience for 50 mm/min (2min)
I appreciate the feedback from @brent113… totally understand your explanation regarding hotend removal neglecting viscosity of the filament, so of course once re-assembling I proceeded with the normal process of marking 120mm out and advancing it (100mm @ 75 mm/min).
First run was 1.5mm / 1.5% off.
After a couple runs I ended of spot on 100.0mm target, and my final E-value was 1.7% different than the E-value obtained with hotend removed. This shows the effect of removing the hotend is small, but not negligable… also certainly not as bad as the 15% inaccuracies some users are seeing out-of-the-box with default E-value of 212.21.
Thanks for the help getting to a successful calibration result!
Im attempting to evaluate/update my esteps. I followed the update guide above. Getting to the point where I type in M83 and then G1 E100 F300, with filament loaded, nothing happens. When I type commands into the send command box and hit enter, nothing. nothing is returned. any help?im missing something.
Yes, as I stated I followed the guide which states to heat up the filament with the handheld device. the part im having trouble with is entering the commands. I type them into the window and hit enter and nothing happens and no info is returned.
Can you push it through manually? If you open up the door on the front and you push down on the filament, does it come out? Maybe the cog wheel has been eating into the filament resulting in it not grabbing onto it anymore.
If you can easily push it through it should just work. (and if you execute the command with the door open you should see the cog wheel spinning).
When you are running the command, the touch screen is still on the nozzle temp screen? because when you move away from that it will stop heating immediately.
Yes still on temp screen and seconds after watching it flow from hitting the feed button. the issue is: the commands don"t work. nothing happens. I am typing into the little window on the bottom left of the LUBAN workspace. “Send Command” window.
Yes usb to Lap top, as the guide states. I have followed the guide to a “T”. The only command that returns any response is “help”, it returns: V: Version Information G: G-Command Line M: M-Command line. Any other thing I type in does nothing.
Hmm, the guide above is wrong I think. It should state G91 (marlin firmware) to put the printer in relative movement mode and not not M83 (klipper & reprap firmware). Snapmaker is Marlin.
I assume you were following the post from @jdubois that stated the M83? That’s wrong. Should be G91.
it might be safe to reboot your machine first if you try again.
Rebooted the laptop and power cycled the A350. Laptop is hooked up to the A350 via USB. Luban is open and Workspace is open. Im typing into the screen in the bottom left, labeled “Send command.” The handheld is on and open to the Control/nozzle screen and the filament is heated up. I send the M92 command, nothing. I send the V command , version 4.1.3 comes back. type in G91, nothing. type in G1 E100 F300, nothing. Type Help, helps commands come back. ANY OTHER command returns nothing and does nothing.
Yes, those are however handled locally in the console application locally and not transmitted to the controller. Those will even give feedback if you’re not connected to any device at all.
Ok I mark 100mm to the extruder, M92 to get the current e value, See that there is 20mm left after the test run of 100mm. Enter the current e value and the 20mm adjustment, get the new E value, from the formula, enter in the console with M92 E XXX.XX enter M500, test the 100mm again and it is still 20mm off. did it all again and powered on off the snap and still the same. It doesnt matter how much I set the Evalue to, it always has some sticking up above the extruder. I have Used G90 to “save” the value and also shut the Snapmaker off and on.
