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[Solved] Benchy failing at 81% every time  

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Dai Wee Mike
(@dai-wee-mike)
Eminent Member
Benchy failing at 81% every time

Hello all.  Cannot get past 81% on my Benchy print. Until this point the rendering is perfect, but as the arches are formed on either side of the wheelhouse, it seems as if the extruder strikes the structure and it is toppled.  Any suggestions?  Thanks, Mike. 

Posted : 14/06/2021 9:34 pm
Dai Wee Mike
(@dai-wee-mike)
Eminent Member
Topic starter answered:
RE: Benchy failing at 81% every time

Guess this must be a tough one based on the flood of assistance 😂. Solved it myself by reducing print speed to 50% at point of fail. Now the proud owner of an almost perfect Benchy. 

Posted : 15/06/2021 7:09 am
Dan Rogers
(@dan-rogers)
Noble Member
RE: Benchy failing at 81% every time

Benchy will fail at the arches if you don't have the first layer adhesion working properly.  Do learn to do a live-z adjustment (post initial Z calibration).  The calibration step gets you ready to adjust Z - which you will have to do fairly often (filament brand change, material type change, color change, etc).

 

Posted : 15/06/2021 2:32 pm
Dai Wee Mike
(@dai-wee-mike)
Eminent Member
Topic starter answered:
RE: Benchy failing at 81% every time

Thanks Dan. This 3D printing is quite the black art. Reminds me of the precision and intuition required in reloading bullets. As I say, was able to get a full Benchy to print when I slowed the rate down to 50% around the arches. I also had the impression that if I reduce the temp of the extruder and or increase the fan speed it might help the plastic harden quicker allowing a more stable bridge to form… or am I on the wrong track here? Fairly confident that my first layer is adhering nicely after reducing it down to -1350 which gives me a solid squish on a clean base…

Posted : 15/06/2021 3:08 pm
Dan Rogers
(@dan-rogers)
Noble Member
RE: Benchy failing at 81% every time

@dai-wee-mike

Nice print.  Benchy is hard to print - after all it is a bench mark of printer and the person doing the printing.  The arch is famous for warping like you have observed - and elements of controlling that can include print chamber temp (depends on materials you are using) - PLA hardly warps at all it gets laid down quite cool in the first place. PETG will warp more - but temperature and fan cooling will help control that.  Slowing down the speed will actually increase the time the new layer has to bond to the old layer - which probably helped some with the arch not curling up.  Thorough investigation of what is the actual failure pattern helps.  Reducing fan (for PETG) might have accomplished a similar benefit.

Posted : 15/06/2021 3:19 pm
jt2oux
(@jt2oux)
New Member
RE: Benchy failing at 81% every time

First layer was the culprit to my benchy failing right around 80%.  Didn't realize there was such variance between filament brands also.  I'm finding myself doing a live Z adjustment after every filament swap out.  Kind of annoying but necessary I guess.  

Posted : 15/06/2021 8:02 pm
Technical Ted
(@technical-ted)
Trusted Member
RE: Benchy failing at 81% every time

If you search on this site you'll find my post where I was looking for answers to the same problem. I originally was using a textured sheet with PLA material. I ordered a smooth sheet and the problem disappeared. It was poor bed adhesion with the textured sheet that was my problem.

Which sheet are you using? The smooth sheet gives much better adhesion so the benchie won't pop off when the extruder starts hitting on the tops of the arches.

Ted

 

Posted : 15/06/2021 8:49 pm
Burpsnart 3D
(@burpsnart-3d)
New Member
RE: Benchy failing at 81% every time

Hi All,

I had similar experience with my first benchy after I put a mk3s+ kit together. it all looked great until the arch when the nozzle just span it loose on the bed. Luckily i was watching and stopped the print before spaghetti stage !

I went back to understanding the first layer calibration. I thought i had it dialled in but in fact i was some way off.

I recommend looking up this thread read it and print some squares 😀 - they certainly helped me understand what was going on.

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

 

Happy Printing 😀 

This post was modified 3 years ago by Burpsnart 3D
Posted : 22/06/2021 10:26 am
Dai Wee Mike
(@dai-wee-mike)
Eminent Member
Topic starter answered:
RE: Benchy failing at 81% every time

Hi Ted. Not sure if the ? was directed @me, but fwiw I use a smooth sheet and after dialing in my first layer height I’ve been off to the races since then with no liftoffs and a high print rate of success. I’m such a noob still -it’s kinda  sad - but haven’t printed with anything except the bundled PLA filament which is doing me just fine for now 😊. Btw I am meticulous about keeping the bed clean and use soap and water occasionally if I get prints on the surface but can usually avoid that by carefully snapping the prints off in place without removing the plate. 

Posted : 22/06/2021 3:05 pm
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