Hi guys,

I've done the very first print with my Mendel90 Sturdy yesterday. I thought the first try would be worse than that, so I am pretty happy with it

Yet, something weird happened, a few small black stains are visible on the printed object and I have no idea what it is or how it got there. Do you have any idea about what happened ? It can be remove with a sharp knife, but it is not great.



One more question, the "skirt" around the object was a bit messed up, the first half didn't stick to the bed. Hopefully the rest sticked pretty well. Should I increase bed temperature ?

Since I am very new to all that, I would be very interrested in any observation concerning this print and how it could be better

Print parameters :
- PLA 3mm
- 0.4mm nozzle
- 0.3mm layers
- Hotend temp : 190°C
- Hotbed temp : 70°C (55°C measured on top of the glass)

Thank you for reading !

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Blog construction Mendel90 Sturdy [In progress]

The black bits could be contamination in the filament, bits of plastic stuck to the outside of the nozzlethat subsequently burnt and fell off, or contamination in the hot end if it is new. Heat it to 80C and then rewind all the filament out. That should bring any crap with it. Cut that bit off and reload the extruder, make sure the nozzle is clean and try again.

The outline looks like the extruder was not primed when you started the print. The first time you load filament run some through the extruder, then turn the heater off and rewind 1mm. The print should then start correctly by extruding a thick line along the front of the bed. By the end of the line it should be fully primed and the skirt should start correctly. Measure the thickness of the skirt and adjust the Z home point if it is not 0.3mm. Subsequent prints should not need any more priming as the extruder should be left full at the end of the print.

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[www.hydraraptor.blogspot.com]

Hi Chris,

Yes, the hotend is brand new, I'll do some cleaning this week-end as you advised.

And yes again, I did not set priming instruction in the Start Gcode, I didn't know what it was meant for. I'll update my Start Gcode (or at leat run that instruction once).

Thanks