Getting a blob on top of Z where print finishes... where should I be looking

Hey, so having received some great advice on my fan adapter thread I though I’d look to get my sonic pad setup and tuned a bit before taking on anything bigger and so far its going well.

With a Calibration Cube print I’m getting +/- 0.05mm average between last 3 tries at x = 20.07mm, y = 20.03mm and z = 20.03mm which from what I’m reading seems to be good results and I’m pretty happy with the corner and wall print quality so all is good… except a blob!

I seem to be getting a blob where the print is finishing so I’m not sure if its related to the nozzle staying at that point for too long after the print or not retracting enough?

Any thought where I might start to look to fix this issue?

What do you have in your slicer for “End G-code” (assuming that it’s Cura)?

There should be an explicit command in the set of gcodes that are run when the print completes to move the toolhead to a corner of the printer - something like:

G1 X0 Y(machine_depth)

Do you have any macros running in your Klipper set up?

I think you’ve pointed me in the right place, I’ve copied the recommended end g-code as provided in the profiles for the Sonic Pad but some of it doesn’t copy right and in a few places it pasted in over two lines which split some of the commands and initially caused issues in the printing as it was seeing them as bad instructions.

I’ve just taken another look and there is a line:

G1 Z0.2 E2 F2400

which should be

G1 Z0.2 E-2 F2400

so I’m presuming that E-2 is tell it to retract -2 and the way I have it is its extruding 2 instead and giving me an extra blob of unwanted filament on the top. Looks like it just didnt copy the minus from the PDF correctly. The whole end g-code as it stands is so I’m thinking its just a case of updating to include the minus on the E2 and it will be happy.

M140 S0
M104 S0
M106 S0
G1 Z0.2 E2 F2400
G1 X5 Y5 F3000
G1 Z10
G1 X0 Y230

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That little correction to put the minus back in sorted it all out - Cheers for the nudge in the right direction :+1: