2. Let’s make sure everything is reliable with the motion system.

Let’s go over the Klipper configuration checks.

https://www.klipper3d.org/Config_checks.html

I’ll assume you’ve already done the emergency stop M112 and thermal ones. If not definitely do them. Always good to be sure that Klipper can safely read temps, and reliably shut things down when it can’t.

Wait for things to cool down if anything’s been heated (such as the bed) and then

• Use M84 in the console.

Can you move the bed freely (but slowly) back and forth?

Can you rotate the Z Lead screw coupler and move the X gantry up and down!

Can you move the X carriage left and right?

• Check the end stops

Move the bed back to its switch. Then use QUERY_ENDSTOPS in the console and check what if reports for Y. Triggered, for example.

Now move it away from the switch. And do QUERY_ENDSTOPS again. Is the switch showing the right state now? Not triggered?

Do the same for X and, if you’re still using the Z limit switch then Z. Let’s make sure the endstops are triggering correctly. These are the means that Klipper has to get a sense of the physical world. After homing everything else is just keeping track of how it’s moved relative to what it knows is the home position (like a submarine navigator using charts and known direction and movement to plot a course)

• Check the steppers.

Home the printer and then move the nozzle so it’s over the center of the bed and move it up to about z100

Then run the following in the console. STEPPER_BUZZ STEPPER=stepper_y

The bed should move 1 mm towards you, then 1 mm towards the back.

Now run

STEPPER_BUZZ STEPPER=stepper_x

The X carriage should move 1mm to the right and then 1mm to the left.

And finally

STEPPER_BUZZ STEPPER=stepper_z

The X gantry should raise 1mm, then lower 1mm

If not then check the configs for changing the pins on the particular stepper. I’d be surprised if this was an issue as I can’t imagine it even homing correctly but we’re doing sanity checks. Assuming nothing so we can rule out things that will affect down stream problem solving.

• Validate the probe is reliable

Home the printer and then run the following

PROBE_ACCURACY

This should cause the probe to be deployed and tested repeatedly. What we’re looking for is the general same value as noted here

https://www.klipper3d.org/Probe_Calibrate.html

There will be some variation but if the results aren’t reliable then it can’t reliably be used for a mesh or homing, etc. of course sometimes it’s a matter of adjusting the speed. Sometimes it’s physical (for example a very loose X carriage which is why we made sure the V roller wheels are right)

Note the Klipper docs on what you’re looking for. It explains how to find the acceptable range based on your actual Z stepper micro steps). Can’t accurately measure something with a tool that gives results larger than the thing you want. E.g. baseball height with a yard stick.

Of course sometimes it’s just a matter of finding the right speed or fixing the carriage (which we covered). Or verifying the connection to the board is good (powered off, obviously) And if that doesn’t work then it may warrant getting a replacement but since it’s worked for you in Marlin it shouldn’t be an issue.

• Verify the extruder.

Disconnect the filament Bowden before it goes into the extruder. And let’s also make sure that any tensioner for the filament is tightened. Not looking for it to be super tight, again just snug enough that the filament will be engaged by the extruder gear and pushed.

Home the printer, then move the Z up to about 150 or so. And turn the hot end on to the proper temp for your filament. Go to the highest temp recommended for the filament if you can since we want to make sure we have the right rotation for the given extrusion amount and so we want to extrude hot and extrude very slowly so we aren’t “fighting” to push the plastic.

Now take a ruler and place one end against where the Bowden goes into the extruder. Then, keeping the filament in line as straight as possible with the ruler, find a spot that marks 150mm and use a marker or piece of tape.

Once the hot end is up to temp issue the following

G91
G1 E100 F60

What this does is set the movement to relative (G91) and the move G1 the E(extruder)100mm at a F(federate) of 60.

So move the extruder 100mm very slowly.

Wait for it to finish and then use your ruler to measure the distance between your mark or tape and the Bowden connection. We asked it to push 100mm, now we’re seeing how much is left of our 150mm. If it’s spot on it’ll be 50. But if it’s over or under then we can use that to adjust the rotation distance (how much to rotate a stepper to move a distance) for the extruder. E.g. this is the same as figuring out the Esteps in Marlin.

So we do a little math (or use excel or any number of online calculators) to calculate our new rotation distance.

Let’s hypothetically say your current rotation distance is 40

And we had 150mm filament and extruded 100. But we end up with 55mm left over (e.g. we under extruded)

Here’s the formula used in Klipper reference rotation_distance = rotation_distance = previous_rotation_distance * actual_extrude_distance / requested_extrude_distance

And we, hypothetically, had 51 mm left between our mark and the Bowden So that’s actual_extrude_distance =150-51 Or actual_extrude_distance =99

rotation_distance = 40 * (99 / 100)

Or rotation_distance = 39.6

And so you’d set rotation_distance under your extruder to 39.6. Then save and restart Klipper so it uses the new value.

Then repeat the test. If you don’t end up with 50mm left over your calculate the new rotation_distance again being sure to use the value that was used (in the config) as of the time you ran it. E.g. in our hypothetical the second time would be with 39.6 instead of 40

Once it’s right connect your Bowden back

• Clean the build plate

After we’ve got all the bases covered let’s take the build plate off and give it a good wash in warm soapy water.

Give it a really good scrub and then dry it. Ideally using something like a shop towel to reduce any towel or napkin fibers getting on the plate. So many times this was the one thing causing me issues with first layer adhesion. It just needed a good wash.

Continued next comment (after I get some sleep. Check back in 10 hours or so) where we’ll do our Z offset with the actual filament until it flows right with our fancy overpowered glue gun like plastic extruder

Edit: Added build plate cleaning