Nozzle Temperature - PLA ABS Outgassing, smell, odor

[Greg C. @gcornell51987gmail-com My Robox is a Blue Commercial Version]

I’ve been using my Robox for a few weeks and it works great except for the bad smell when printing. When talking to a couple buddies who use PLA and ABS in their professional 3D printers, they were definitely concerned. They said they can print all day long without odors - even without use of fume hoods. I’ve just started playing around with decreasing nozzle temperature as they said I may be overheating the filament and causing it to outgas. I’m using the Robox smart reels, so I assumed they’d be programmed with the correct settings. I just completed a print with nozzle temperature 10C below default EEPROM settings - part came out fine and odor decreased, but still noticeable. Jumping down to 20C below default and trying again as I type this.

Anyone have any experience or insight on this?

[BHudson @bhudson I have several Robox units Kickstarter and Commercial Arizona, USA]

@gcornell51987gmail-com ABS will smell when printed. The Robox prints ABS at the same temperature or maybe a little lower than every other machine on the market. PLA will also have an odor, but it is not as pronounced as ABS and is not unpleasant.

https://www.matterhackers.com/articles/how-to-succeed-when-printing-with-abs

I have personally printed with Robox ABS and PLA and also with other brands of both PLA and ABS and the CEL PLA has the lowest print odor of any PLA I have used. Their ABS is about middle of the pack for odor.

Heating plastic will cause outgassing. It is part of what happens when you heat any plastic. Some chemicals in the plastic are vaporized and come out. It is unavoidable. ABS will start to smell and outgas if left in a car on a hot day. That film on the inside of your windshield on a car? ABS and vinyl outgassing byproducts.

Every 3D printer should be used in an area with good ventilation as there will always be some airborne byproduct released by the process of melting plastic.

I operate two Betas and one Production Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/ben

[Greg C. @gcornell51987gmail-com My Robox is a Blue Commercial Version]

Since my original post, I’ve ran a few basic experiments using the original PLA included with my printer:

Print 1: Nozzle temperature 195C (original setting)

- On a relative scale of 1 to 5 (5 being the strongest odor and 1 being zero odor) we’ll call this a 5 as the benchmark for odor and print quality a 5 (5 being the highest quality). Material came out of nozzle as smooth liquid and no other effects observed.

Print 2: Nozzle temperature 185C

- Odor was 3 out of 5. Noticeable decrease, but still obviously present. Quality still a 5 with no real quality change observable. Material came out of nozzle as smooth liquid and no other effects observed.

Print 3: Nozzle temperature 175C

- Odor was 2 out of 5. Again, a noticeable decrease and this time the odor could hardly be detected. Quality still seems to be a 5 with no real quality change observable. When the Robox did the initial nozzle wipe, the 0.3mm nozzle material did look to harden a bit quicker as it hardened in a bit more of a loopy pattern instead of the nice straight line it usually is.

Print 4: Nozzle temperature 165C

- Odor was again a 2 out of 5. Quality went down to a 4 as there are few very small noticeable defects in the surface. On the initial wipe, the 0.3mm nozzle material was even more loopy (almost globby).

Print 5: Nozzle temperature 180C

- Odor wen up to a 3 or 4 out of 5 and quality back up to a 5.

Print 6: Nozzle temperature 175C

- Confirmed odor decreased from 180C and quality did not decrease. Even had the wife come into the room and she said she could hardly notice an odor.

Based on this, it does seem there is a substantial amount of additional odor released between 175-180C. There also doesn’t seem to be a significant quality decrease. Note: I am using the Robox robot model included on the USB at 25% of it’s original size for quick, but detailed print samples. For quality, I am only commenting on surface appearance and have done no real tests on mechanical properties.

 

Interested to see if anyone else has done similar tests or has thoughts.

 

PS. From my 1st post, confirmed with my buddies (2 separate companies) that they are use Stratosys printers with no ventilation.

• This reply was modified 3 months, 2 weeks ago by  Greg C..

[BHudson @bhudson I have several Robox units Kickstarter and Commercial Arizona, USA]

@gcornell51987gmail-com You can’t compare a Robox with a Stratasys printer. They are in two completely different categories. The Stratasys printers have built-in filtration and use a customized material blend. The Robox is built for a consumer level printer that can use just about any material and is built to a much, much lower price point. This means that the customer needs to accept there are some differences from a professional grade printer.

I am glad you are able to get good results at a lower temperature and appeal to your sense of smell. Do note that once you start speeding up the prints you will not be able to continue that low print temperature.

Is the odor from PLA really that offensive? It smells kind of like popcorn to me. Not unpleasant in the least.

I operate two Betas and one Production Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/ben

[Greg C. @gcornell51987gmail-com My Robox is a Blue Commercial Version]

@bhudson Thanks for the feedback on the differences between the Stratasys and the consumer printers. I was wondering if that is the case, so that’s why I included that bit of information.

The odor from the PLA was definitely not popcorn or “organic” as others have said as well. That’s what had me concerned. It was definitely a burning plastic type of smell. Rather than a “kind of like popcorn” comparison, I would say “kind of like the smoldering electronics”.

[BHudson @bhudson I have several Robox units Kickstarter and Commercial Arizona, USA]

@gcornell51987gmail-com For the first several hours of using a new print head, there will be a chemical or burning smell from it as the excess sealant used on the gaskets burns off. This can smell like burning electronics and it can take anywhere from 2 to 20 hours of printing to totally dissipate depending on how much sealant was used and how hot you run the print head.

I operate two Betas and one Production Robox.
See my 3D Hub site at https://www.3dhubs.com/phoenix/hubs/ben

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