.8mm Nozzle Settings PETG - COVID19 Prints  

RE: .8mm Nozzle Settings PETG - COVID19 Prints

Hi Shared, 

I have not used a 0.8mm nozzle, but one of our users, 'Bobstro' has written various notes on the subject of different nzzle sizes and also optimising printing for covid19 products. 

Please have a look at his page 

http://projects.ttlexceeded.com/3dprinting_techniques_covid_printing.html

regards Joan

RE: .8mm Nozzle Settings PETG - COVID19 Prints

Posted by: @shared

Hi guys, I've been printing face shields with the stock .4 nozzle but want to use a .8mm nozzle. 

I've been doing the same. For most of the shield frames, a 0.6 and 0.8mm nozzle offer similar performance. The biggest gain comes when printing PETG with a larger nozzle. You can achieve far higher speeds than the default PETG profiles permit.

Be sure to do a test print to verify fit. Features will be a bit rougher with the larger nozzle, but they work well. I recommend using variable layer height for optimal speed:fit results. More notes on the page Joan linked to.

Can you please share the settings or any profile.

I have a set of sample profiles including nozzles in a range of sizes. Be aware that I use the PINDA warming routine on startup, so there will be a long pause as the printer waits at the start of a print. On a cold day, this may take several minutes. You can monitor the PINDA temp as it warms to 35C by observing the Support->Temperature display on the printer menu.

If you'd care to DM me, I'd be happy to help you get going on Hangouts or similar.

RE: .8mm Nozzle Settings PETG - COVID19 Prints

Thank you for the support. I was able to get it running using Cura.

35 Munutes to print two

RE: .8mm Nozzle Settings PETG - COVID19 Prints

@bobstro

I'm trying to print the visor style face mask with .8mm and am have quite the time with the visor portion (see pic). Any suggestions? I slowed down, increased temp, and tried reducing extrusion width. It's definitely has to do with the small width of the visor portion. 

RE: .8mm Nozzle Settings PETG - COVID19 Prints

Posted by: @dave-b10

I'm trying to print the visor style face mask with .8mm and am have quite the time with the visor portion (see pic). Any suggestions? I slowed down, increased temp, and tried reducing extrusion width. It's definitely has to do with the small width of the visor portion. 

There is a simplified version of the NIH-approved print that we are using in the MA Masks for Docs group. One of the things they did was simplify the shield and make it smoother so it will print with unbroken lines. That may help.

What filament are you printing with? I found that as I push speeds and throughput up with PETG, inter-layer adhesion suffers. I've had a less dramatic version of that problem, usually with 5-6 strands coming loose across the inside of the outer band. That shield also has significant overhangs. The ways I've dealt with it on this specific print:

• Set extrusion width for perimeters and external perimeters to exactly nozzle size (e.g. 0.8mm). This is to improve the ratio of material supported to material overhanging on the inside of the visor.
• Decrease external perimeter speed. I'm using 100mm/s for all but external perimeters which are at 60mm/s.
• Disable printing external perimeters 1st. Our local group said enabling that feature improved prints, but I'm getting good prints without it and it makes overhangs more difficult to print.
• Increase PETG print temp 10C to improve inter-layer adhesion with the larger nozzle at speed. I'm using AmazonBasics/Overture PETG so am at 260C, 10C above their recommended numbers.
• This is counter-intuitive, because we increased heat above, but I've set Filament Settings->Filament->Cooling->Cooling threshold->Enable fan if layer print time is below to 45 seconds and a Fan speed range of 30-50%. This turns the cooling fan on at low speed for the visor part, improving external finish. 

I tested with a 0.8mm nozzle and found it made little improvement over print times compared to a 0.6mm nozzle. If you can't get good results, it might be worth knocking back to a smaller nozzle.

I'm trying to keep my COVID printing notes page up to date. There are some samples there you can check out.

Happy, healthy printing!