Nozzle's hole shape... Hi, I wonder if changing the shape of the nozzle's hole could help to reduce the visible step between two layers without need to reduce the height of the layers (I know that some of you are printing at 0.02mm by layers but it is too tricky to reach for a newby). The aim is to change the section of the extruded plastic from : www.flickr.com mod_embed_images_loadimage('16ea1822b274dab03a7d424cde8154e0', '/forum/thumbcache/d3c/cfc/fd8/f43/c3b/c0d/59a/1ea/da2/e84/5c_800x400.jpg', 'http://farm8.staticflickr.com/7172/6683591059_46091294fe.jpg', 'https://reprap.org/forum/addon.php?70,module=embed_images,check_scaling=1,url=http%3A%2F%2Ffarm8.staticflickr.com%2F7172%2F6683591059_46091294fe.jpg', 'http://www.flickr.com/photos/71799976@N08/6683591059/', 113454, 800, 400, 'Loading image ...', false); TO www.flickr.com mod_embed_images_loadimage('b2bfcba0ab77e2f476704584025ba0ea', '/forum/thumbcache/6ee/7fa/742/2e5/681/8f4/3c5/26a/9d6/551/69_800x400.jpg', 'http://farm8.staticflickr.com/7005/6683591137_9b00f5b68e.jpg', 'https://reprap.org/forum/addon.php?70,module=embed_images,check_scaling=1,url=http%3A%2F%2Ffarm8.staticflickr.com%2F7005%2F6683591137_9b00f5b68e.jpg', 'http://www.flickr.com/photos/71799976@N08/6683591137/', 113454, 800, 400, 'Loading image ...', false); To control the angle of the layer, it could be possible to use a square hole nozzle (or some shape with edges, triangle for exemple) which rotate around the hotend axis. I just do some experimentation with a mastic gun (so don't be affraid by the extrusion quality) : First with the round nozzle (top extrusion): www.flickr.com mod_embed_images_loadimage('d028e50e1ea1e9c56e06e7e31ba645d6', '/forum/thumbcache/9d8/970/8be/d76/2da/282/737/147/1ae/30b/74_800x400.jpg', 'http://farm8.staticflickr.com/7002/6683714963_a39d50b65d.jpg', 'https://reprap.org/forum/addon.php?70,module=embed_images,check_scaling=1,url=http%3A%2F%2Ffarm8.staticflickr.com%2F7002%2F6683714963_a39d50b65d.jpg', 'http://www.flickr.com/photos/71799976@N08/6683714963/', 113454, 800, 400, 'Loading image ...', false); Then with the square nozzle : www.flickr.com mod_embed_images_loadimage('ab977bfcfd6fe3b5b424a00ef943a4cb', '/forum/thumbcache/0a0/5bb/f69/729/4ac/9d9/f76/afe/48e/768/4a_800x400.jpg', 'http://farm8.staticflickr.com/7023/6683715383_38e942e3f5.jpg', 'https://reprap.org/forum/addon.php?70,module=embed_images,check_scaling=1,url=http%3A%2F%2Ffarm8.staticflickr.com%2F7023%2F6683715383_38e942e3f5.jpg', 'http://www.flickr.com/photos/71799976@N08/6683715383/', 113454, 800, 400, 'Loading image ...', false); This pictures are to be well understood more than a reliable experimentation. Guillaume https://reprap.org/forum/read.php?70,113454,113454#msg-113454 Sun, 06 Sep 2026 20:28:36 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?70,113454,120076#msg-120076 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,120076#msg-120076 Andrew Diehl Plastic Extruder Working Group Tue, 21 Feb 2012 10:47:39 -0500 https://reprap.org/forum/read.php?70,113454,119755#msg-119755 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,119755#msg-119755
maybe i'll make one and see what it does.]]> aplavins Plastic Extruder Working Group Sun, 19 Feb 2012 16:45:14 -0500 https://reprap.org/forum/read.php?70,113454,119753#msg-119753 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,119753#msg-119753 -------------------------------------------------------
> Great idea! How would one make a 0.5mm star shaped
> hole?

... make a thin walled hole with 1mm and hammer or squeese it to a square and further to a star shape ...]]> VDX Plastic Extruder Working Group Sun, 19 Feb 2012 16:32:07 -0500 https://reprap.org/forum/read.php?70,113454,119420#msg-119420 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,119420#msg-119420
A water cut die perhaps?]]> aplavins Plastic Extruder Working Group Sat, 18 Feb 2012 02:19:39 -0500 https://reprap.org/forum/read.php?70,113454,113494#msg-113494 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,113494#msg-113494
Quote
nophead
> This all assumes the plastic will come out square
> from a square hole. While this may be true for a
> paste it may not be for molten plastic. Die swell
> might make it rounded anyway.

In fact, even with the mastic, to extrude a square you have to use a kind of 4 branches star like that .

We have to take into account the release of stress due to extrusion. But IMHO, in the same conditions, paste and molten plastic should have the same behaviour.
]]> MyMaker Plastic Extruder Working Group Thu, 12 Jan 2012 10:07:04 -0500 https://reprap.org/forum/read.php?70,113454,113470#msg-113470 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,113470#msg-113470
This all assumes the plastic will come out square from a square hole. While this may be true for a paste it may not be for molten plastic. Die swell might make it rounded anyway.]]> nophead Plastic Extruder Working Group Thu, 12 Jan 2012 07:53:51 -0500 https://reprap.org/forum/read.php?70,113454,113463#msg-113463 Re: Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,113463#msg-113463
It's an interesting idea to use a different shaped nozzle hole. Presuming your sketches are looking at the model from the side I can see how it could improve the look of layers on vertical walls, but I think you will still get "steps" between layers when there is overhang or underhang.

Regarding moving the nozzle around the hotend axis I would imaging that introducing any mechanisms to the actual hot-end could lead to leaks. I'd be interested in seeing your designs on this.

Cheers,
Gary]]> garyhodgson Plastic Extruder Working Group Thu, 12 Jan 2012 06:48:55 -0500 https://reprap.org/forum/read.php?70,113454,113454#msg-113454 Nozzle's hole shape... https://reprap.org/forum/read.php?70,113454,113454#msg-113454 I wonder if changing the shape of the nozzle's hole could help to reduce the visible step between two layers without need to reduce the height of the layers (I know that some of you are printing at 0.02mm by layers but it is too tricky to reach for a newby).

The aim is to change the section of the extruded plastic from :

TO



To control the angle of the layer, it could be possible to use a square hole nozzle (or some shape with edges, triangle for exemple) which rotate around the hotend axis.

I just do some experimentation with a mastic gun (so don't be affraid by the extrusion quality) :
First with the round nozzle (top extrusion):


Then with the square nozzle :


This pictures are to be well understood more than a reliable experimentation.

Guillaume
]]> MyMaker Plastic Extruder Working Group Thu, 12 Jan 2012 06:02:57 -0500