Sharp top edges  

RE: Sharp top edges

was that after having multiple parts at that height on the plate?  There is a setting in the slicer (advanced) for specifying how much time can be spent on a layer.  That's what's happening here - the head is centered at high temp around this little area.

I have some lures that had that issue (sharp edges and cone shape tail sections) - and was able to tame the melting at the tip by 

Disabling linear advance (M900 K0)

Increasing fan speed.

Printing two at the same time.

Increasing extruder multiplier by .1 (gets the job done faster, makes a tougher part)

RE: Sharp top edges

Success!  I think.  I will post what I did after the print is complete.  

The cones are for fire and forget experimental rockets to test 18mm F motors.  Should reach Mach 2.  

RE: Sharp top edges

@charles

If you would care to post a .3MF I'd be willing to give it a go.

RE: Sharp top edges

@swiss_cheese

I go it to work near perfect.  

I was getting a little frustrated with the tips.  The incresed fan and slowing it down worked.  

Settings:

100% fan

after 30s per layer, I slowed it down to 8mm/s.  

I am only charging the guy $5 for 20 of these.  Hopefully it drums ups some buisness. 

RE: Sharp top edges

Not perfect - but it will do.

RE: Sharp top edges

Hey Chuck, missed your question. I would have suggested a 2nd part too. I do use some fan (30%) for PETG for finish on overhangs. That would apply here too. Sounds like you've done all that. A couple of thoughts:

Cura has a nice feature to physically move the nozzle away when layer print time is lower than the specified setting. This reduces the heat buildup from just slowing down.

Have you experimented with wider extrusion widths? That might reduce the amount of time on layers near the tip since there will be fewer perimeters.

What part of the tip is that pic showing?

RE: Sharp top edges

@charles

Good deal, glad you got it handled sorry I was late to the party 😎 

RE: Sharp top edges

@bobstro

The tip the the sharp end of the nose cone.  This nose cone is 17mm at the base and pure cone.  I have never printed a cone.  I think the tip so so small that it created an issue with the hot filament.  

RE: Sharp top edges

I'll try this one in PETG when I get a chance. What size nozzle are you using?

RE: Sharp top edges

Nozzle X 0.4mm

RE: Sharp top edges

Here's a quick comparison of my results:

• The full tower at top was sliced with PrusaSlicer and printed in AmazonBasics PETG with a 0.5mm nozzle and 0.9 extrusion multiplier with cooling from 30-75% for layers below 15 seconds at 230C.
• The tip at bottom was sliced with Cura with the same basic settings, but using Cura's "back off" cooling below 10s.

I think physically moving the nozzle away helps more than just slowing down.

RE: Sharp top edges

I am going to switch to ASA.  PETG might be the wrong filament.  

RE: Sharp top edges

Posted by: @cwbullet

I am going to switch to ASA.  PETG might be the wrong filament.  

That is exactly what I thought, when you first posted this.