Speed and Strength - 0.75mm Nozzle?

Ask the MakerGear community for assistance...
Post Reply
CCRN
Posts: 180
Joined: Wed Jun 01, 2016 6:15 pm

Speed and Strength - 0.75mm Nozzle?

Post by CCRN » Sat Jul 01, 2017 4:06 am

I designed a model for work that broke too easy at lower infill. It needs a high amount of infill to have durability and to keep them from being broken accidentally. I decided on eSun PETG and I cranked up the infill and some border thickness until the prints became as strong as I felt they needed to survive general use. My initial nozzle is 0.35mm with Auto on the width. The issue I am running into is the print is taking around 24 hours to print even though S3D says 10. Print speed is 80mm/sec. I have to figure out how to speed it up, but also maintain strength and function.

My design is boxy and functional and has no real fine detail, so I was thinking a larger diameter nozzle say 0.75 mm would help to print it faster. I really haven't used one except for the 0.50 mm one for ninjaflex. I don't have any experience with settings for the larger 0.75 mm nozzle in S3D.

For models with no surface detail, would the 0.75 mm nozzle be a better choice for me and cut down my print time without sacrificing strength?

Thanks,
Jerold

User avatar
ednisley
Posts: 1155
Joined: Fri Apr 11, 2014 5:34 pm
Location: Halfway up the Hudson
Contact:

Re: Speed and Strength - 0.75mm Nozzle?

Post by ednisley » Sat Jul 01, 2017 1:01 pm

CCRN wrote:taking around 24 hours to print even though S3D says 10
That's typical: the time estimate doesn't include the acceleration limits imposed by the firmware.
would the 0.75 mm nozzle be a better choice for me and cut down my print time
Probably not as much as you'd expect.

A 0.35 mm nozzle can extrude about 10 mm³ of plastic per second, so a 0.75 mm nozzle should extrude 46 mm³/s, based just on the area ratio. Increasing the thread width from 0.4 mm to 0.9 mm and the thread thickness from 0.25 mm to 0.6 mm will just about soak up the additional volume.

Because the incoming filament diameter remains the same, the extruder motor must turn 4.6 times faster, moving the filament at 19 mm/s instead of 4 mm/s. You may need to reset the maximum motor speed and tweak the acceleration limits to make retraction work correctly. Adjusting the slicing parameters will surely improve the part's appearance, too.

However, the hot end must bring the plastic up to the proper temperature in 1/4.6 the time and that probably won't work, because the M4 hot end is barely 20 mm long: the melt time would be 1 second, instead of 5. There's a definite upper limit to how fast the hot end can transfer heat into the moving plastic and 19 mm/s will push it hard.

If that's the case, then you must reduce the maximum extrusion speed, perhaps by a factor of 2, which means the big nozzle cuts the print time down by only a factor of 2.3 (-ish).

If the larger thread dimensions improve the part's mechanical properties, the larger nozzle may be worthwhile, but it can't make the parts pop out of the printer in hours, rather than days.

Bratag
Posts: 438
Joined: Wed Jan 14, 2015 5:33 am

Re: Speed and Strength - 0.75mm Nozzle?

Post by Bratag » Sun Jul 02, 2017 7:22 am

I found a nice balance with a .6mm nozzle. I can still print relatively fast (though I need to bump the temp slightly) and parts are printed considerably faster than with my .4mm. It does take some time to dial in the print settings but it can be a nice way of cutting down some time.

Also for better time estimates of prints you might look at http://www.gcodeanalyser.com/

CCRN
Posts: 180
Joined: Wed Jun 01, 2016 6:15 pm

Re: Speed and Strength - 0.75mm Nozzle?

Post by CCRN » Sun Jul 02, 2017 5:14 pm

Thank you both for responding.

Jerold

User avatar
insta
Posts: 2006
Joined: Tue Sep 16, 2014 3:59 am

Re: Speed and Strength - 0.75mm Nozzle?

Post by insta » Mon Jul 03, 2017 6:53 am

The video is years old (and potato-quality), but here is a 0.66mm V3a running PLA @ 220C.

I was using 0.50mm layers at 120mm/sec print speeds. Nothing modern can touch it -- even a Volcano. Try it out -- there's occasionally folks selling V3a's in the FS section. It'll cost you $15 to get one, and I'm pretty sure the V4 nozzles will fit well enough, if you can figure out the jam-screws.

https://www.youtube.com/watch?v=BGJska4xnyw
Custom 3D printing for you or your business -- quote [at] pingring.org

User avatar
ednisley
Posts: 1155
Joined: Fri Apr 11, 2014 5:34 pm
Location: Halfway up the Hudson
Contact:

Re: Speed and Strength - 0.75mm Nozzle?

Post by ednisley » Mon Jul 03, 2017 4:47 pm

insta wrote:0.50mm layers at 120mm/sec
In round numbers, that's 0.8 x 0.5 x 120 = 48 mm³/s, five times faster than the 10 mm³/s I'm noodling along at.

Note the V3a has a long long <i>long<i> hot end, maybe 35 mm, with the heater wound all over it, for plenty of melt time while the filament travels along.

Maybe not quite enough capacity to print lawn furniture (*), but certainly good enough for a fat nozzle!

I'm pretty sure the nozzle threads aren't interchangeable, though.

(*) This is a hot end:
http://www.3ders.org/articles/20120213- ... idges.html
Last edited by ednisley on Fri Jul 07, 2017 1:28 am, edited 1 time in total.

User avatar
insta
Posts: 2006
Joined: Tue Sep 16, 2014 3:59 am

Re: Speed and Strength - 0.75mm Nozzle?

Post by insta » Thu Jul 06, 2017 7:22 pm

ednisley wrote:
insta wrote:0.50mm layers at 120mm/sec
In round numbers, that's 0.8 x 0.5 x 120 = 48 mm³/s, five times faster than the 10 mm³/s I'm noodling along at.

Note the V3a has a long long <i>long<i> hot end, maybe 35 mm, with the heater wound all over it, for plenty of melt time while the filament travels along.

Maybe not quite enough capacity to print lawn furniture (*), but certainly good enough for a fat nozzle!

I'm pretty sure the nozzle threads aren't interchangeable, though.

(*) <i>This</i> is a hot end:
http://www.3ders.org/articles/20120213- ... idges.html
The nozzle threads are interchangeable (both M6) but the internal sealing geometry might be different.

I also had to run it at 19v to keep up with the PLA soaking heat out.
Custom 3D printing for you or your business -- quote [at] pingring.org

Bratag
Posts: 438
Joined: Wed Jan 14, 2015 5:33 am

Re: Speed and Strength - 0.75mm Nozzle?

Post by Bratag » Thu Jul 06, 2017 9:33 pm

I was printing at 245c with my E3D for white PLA at 65mm/s using the 0.6mm with 0.45mm layer height. Its bizarre to see the spool moving that fast. It did however cut the print time on the object I was printing from 3+ hours, at .35mm layer height, to around 1hr 40m so definitely worth it for me. Because the M2 is such a beast as well the quality was still great.

Post Reply