Decided to see how fast I could print Polar Black PHA and I should have set the end higher than 25 I guess. Though the last filament ran off the spool as it finished so maybe not? Anyhow, to my eye I don't see anything amiss except maybe the tiniest set of blips on the long face about 4-5 layers down from the top and towards the right side? Anyone else spot any issues?
I swear I've gone through a bit over a roll just dialing things in but I think I've found what seems to work for my particular setup.
Printer: Bambu H2D
Build Plate: Bambu Supertack Pro(which apparently is not the same as the original supertack)
I tried the standard textured pei plate that came with the printer as well as the smooth PEI both with and without gluestick or liquid glue and a large(10mm+) brim. Textured PEI did not seem to provide enough first layer adhesion. The supertack initially gave so much that I abandoned it as incompatible and tried the smooth pei. Smooth is definitely better than textured but still not awesome IMO. My "to be composted" box must have a million of the little 4 pointed warp test stars in it I found on this forum while testing.
The supertack won me over once I gave it another shot, but this time with the modification of printing the first layer at a low temperature. I actually tried printing at less than 100% coverage too for easier removal but while removal was easier it also pulled part of the first layer off. What works a lot better is printing cold and at a low temp for the first layer. This lowers the stickyness enough so the PHA doesn't weld to the build plate and require a metal scraper to remove. I was using 183 C for a bit and am now using 184. For larger parts I'd consider bumping it up 1 degree at a time if the adhesion wasn't strong enough. However, I have never had a part pull itself off the supertack due to warp. Not once. This thing has a crazy grip, do not print a hot first layer!
The final thing I do is use isopropyl alcohol to aid in releasing the print. I just pour a little in the cap and dump it around the print perimeter and then drag it around the print with a finger to ensure its fully wet all around. Water does not work as it is repelled from the plate. Then remove the plate and bend to release or mostly release. This is a much stronger bend than your usual PLA or PETG removal from textured PEI but it will usually come almost all the way off. Stick the plate back in and wiggle the print gently to get the alcohol under any remaining stuck bits and try and get it to release gently. The more you peel it off vs pull it off the less cleanup you have to do once its off. Most times there is a little outline where it stuck the strongest. Use a fingernail and alcohol or a cloth and alcohol and rub it off.
As for the my printing settings I'm currently using a .4 high flow nozzle set to 184 first layer as mentioned above and 210 C for the rest of the print thanks to the advice of others here especially u/Hinagea. Flow rate is at 1.02 at the moment and fan at 25-45 without any use of the auxfan. I did try 0 fan but got a lot more PHA buildup on the nozzle than without so I'm keeping a little fan to keep that at bay. I have the chamber fan set to 50% and the door closed and things seem alright. I don't like printing with the door open due to my cats who are VERY interested in what's going on inside the printer. While I haven't done a flow test I think my prints have been doing alright with the max volumetric flow set to 15. Also I tend to lower the first layer and the top layer flow rate to about .95 as for the low temp of the first layer I think its too much and for the top layer the reduced flow gives a nicer finish.
Here are some of the items I've printed.
Ego battery wall mount. Under 100g and I think it came out ok. Note that it is a LOT smoother looking than it appears for the layer lines up the arch part. The lighting just killed it there.
A very specialized jig so I can use a center punch to mark pieces of 1/4" thick angle AL for punching holes. Just slide the piece in, put the center punch in each hole and hit with a hammer and its ready for the punch press.
Hi,
Been lurking for awhile scouring this forum for any bits of info that will help as I adjust to printing PHA. Seems the first kg or so is going to test models or sections of things I actually want as I try out different settings.
I was wondering what most people are using as there seems to be a rather wide range in the various posts ranging from below 190 in some cases to 215. After running out of black Ecogenesis I am now on the same in Polar Filament and as it seemed to print a smidge different I did a whole round of temp tests from 193 to 210 and flow rates from .94 to 1.03. Long story short my part seemed to print mostly fine on Ecogenesis at 193 and .94 flow but on Polar I noticed the return of a "wavyness" and loose outer layer in spots.
I now have good results using 210 and 1.03 flow with fan set to 25-45% and aux fan off. Volumetric flow is 15. While parts do have some warp once off the build plate I have found my Bambu Supertack Pro plate to have zero issues with parts popping off. Its so sticky I almost couldn't use it at first until I learned that I could get good release with the first layer at 184, which is a little odd but using a high temp for the first layer on that plate means the parts don't come off basically.
So my question: Is 210 an acceptable temperature for most things or no. I see it recommended here but mention of PHA degrading at anything above it here?
