Do sharper nozzles handle overhangs better?

This might be one of those things where everyone but me just knows this, but...

I have a deltaprintr mini hot end on one printer, which has a quite sharp nozzle and printing ABS with no part fan, I get really good overhangs, no issues at all. Where as my other printers which are all e3d type nozzles often print much less precise overhangs.

Anyone else see this effect or is something else going on?

Edited 1 time(s). Last edit at 12/27/2016 08:01PM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

From my experience it is a clear yes. Also Bridges are printed much better.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

My diamond hotend curls as hell, I wish I could mill a recess into to the nozzle tip.

Does the flat tip of the nozzle impart more heat and allow for less cooling? Got any pictures of the prints?

Not the prints are messy, but extruding in free air curls the filament. That's a big problem with bridging. I have an 0.4mm nozzle cleaner ordered, maybe the whole channel is bad?

I'd say there is something to the idea that a wider flanged nozzle imparts more heat (and friction?).

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I don't know about nozzles, but the tip of an solder iron is the hottest, where it has the smallest diameter. But at the same time, it has the lowest thermal mass and cools down faster, than a thicker tip.

My filament will occasionally curl out of the nozzle when extruding in mid-air, thought it was just a thing, never considered the shape of the nozzle (using an E3D) to be a factor. However when bridging, I assume you want to "stretch" the filament out over the bridge, pulling it into a straight line. So I would assume if it is curling on you, perhaps you need to speed up your bridges?

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Kurzaa
My filament will occasionally curl out of the nozzle when extruding in mid-air, thought it was just a thing, never considered the shape of the nozzle (using an E3D) to be a factor. However when bridging, I assume you want to "stretch" the filament out over the bridge, pulling it into a straight line. So I would assume if it is curling on you, perhaps you need to speed up your bridges?

If the filament stretches you get unconnected strands. Curling filament is an indicator for an uneven or damaged nozzle opening.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]

Perhaps, but the effect I observed with my quite sharp nozzle on the mini hotend was that when printing an overhang there was none of the usual tendency for the filament to curl upwards creating a slight ledge onto which the next layer doesn't sit very well. It might be more to do with the mini hotend having a very small heater not the usual (in comparison) fairly large heater block of an E3D i.e. far less radiated heat.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I use very pointy airbrush nozzles with the Merlin and it is pretty easy to see that the filament only realy curls when the nozzle is damaged. A very light curl might still occur, but nothing serious. Since i used the Merlin with and without shielding the heater block i can say that from my experience the curl is not connected to heat radiation.
From my pov the biggest difference is that a flat nozzle (like the E3D uses) will stay in contact with extrudes filament while moving over it (ironing). While this makes it easy to create smooth surfaces it wreaks havoc with bridges and from my experience is detriminal to overhang as well. To be fair, the original nozzles from the E3D are sharper than most, they are only flat compared to airbrush nozzles. On the downside pointy nozzles require more precise calibration to deliver smooth surfaces than flatter nozzles.

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[www.bonkers.de]
[merlin-hotend.de]
[www.hackerspace-ffm.de]