3D Printing Materials to Motivate the Mad Maker Inside
Performance Matters; when you receive your spool, using it on your 3D Printer, all the way to how satisfied you are with your 3D Printed part. Like baking or cooking, the ingredients chosen for a 3D Filament formula along with their precise method of preparation has a big impact on the finished product. Smelly outgassing from degraded polymer, dimensional inconsistencies in printed parts, mechanical properties and more are all affected. I've been astonished at how many manufacturers take for granted that the filament they produce will be melted once again in the users 3D Printer and that the resin, colorants, carriers, modifiers and additives have a dramatic role in giving high quality results. Making great PLA Filament is more than pointing your finger at the first 'Extrusion Grade PLA' on a supplier's index and using your old PVC based colorants (I've seriously seen PVC based carriers in PLA from American Manufacturers).
This is Purpose Driven Filament. I make and use these materials around my family, house, and pets; performance and safety are nonnegotiable.
- 3D870 HTPLA+ is a strong, Impact Modified High Temperature PLA. A great choice for easy, precise 3D Printing in engineering, industrial, or hobby applications.
- 3D850 HTPLA is an economical work horse High Temp PLA that can withstand boiling water and is dishwasher safe.
- Mad Maker PLA+ is strong and flexible, with excellent bed adhesion and layer strength. Capable of very high detail with small nozzles at low temperatures and high throughput with large nozzles at high temperatures in situations where other PLA would fail.
Is Other Filament Better? - Well I haven't tried everybody's filament so I can't say. But if you find some you like better you should let me know because that's the one I'll work to beat.
Getting the Best Results - can still take time and patience to dial in the proper settings. Every manufacturers 'PLA' flows, contracts and sets differently and does so uniquely on each 3D Printer. Broadly speaking I've found that the temperature of the hotend, the speed of the printhead, and the flow rate of plastic out of the nozzle have the most profound effect on print quality aesthetically, dimensionally, and mechanically.
Temperature - While it may seem like a great idea to just print hot and fast and use a lot of cooling. Parts can suffer from inbound stresses, reduced layer strength, and effected fluid behavior messes up infill, walls and surface finish. Now, printing at fast head speeds or high flow rates DOES require higher temperatures and is a completely valid way to print if you are aware of the effects and limits. But...
For every given combination of head speed and flow rate (that is your layer height and trace width) you will find a bound of workable temperatures of which the lower end is likely to give substantially better results. Personally, I've noticed huge improvements dialing in the last two or three degrees. Especially on overhang and bridging performance. (I'll get some pictures up, it's really interesting.
Head Speed - Plastic sticks to other plastics, metal, fabric, lots of things. How it sticks, curls, contracts, etc. has a lot to do with the residence time your print head has over where it is printing. The plastic needs to be more inclined to stick to the layer or bed beneath it rather than the nozzle it's coming out of, and the layer beneath it needs to have had enough time to properly cool (read slow) beneath its glass transition temperature (see above). I'm still surprised how many different issues are solved by slowing down. Yes, I want that part made, but I'd rather it be made how I want it than finish 30 minutes sooner and end up in the composter.
Flow Rate - Yikes, this one is where most of your problems and (consequently) solutions reside. Determined by the cross sectional area of a printed trace as defined by layer height and width then multiplied by the head speed; this is a measure of how much actual plastic is being forced through the nozzle. The basic idea is to roughly scale your temperature with your flow rate. Narrower trace width, smaller layers, slower head speed, turn that temp down to match. Now many Slicers will try and help this along by automatically adjusting wall widths to keep a consistent trace area or adjust temperature to match flowrate but you still have to feed in those starting numbers to match your plastic and remember you're dealing with factors like temperature change times at the hotted or sudden flow rate changes when switching between infill, inner, and outer walls. But it doesn't have to be hard, or complicated, or make you feel like your banging your head against a brick wall.
My Advice for Settings that balance Appearance, Performance, and Print Time are:
- Low Temp and Slow Head Speed, at least at first with a new material.
- As best as you are able match your flow rate across all your different trace types like infill, top, bottom and walls.
- Use big, wide traces for infill. Say, double your nozzle width at half your normal head speed.
- Print out walls with your most narrow trace width to keep fine detail.
- Slow head speeds and narrow walls give better detail and finish but reduce your flow rate. Experiment to find the head speed and trace width that gives you the vertical wall cornering and detail you want then; then build your other settings off the associated flow rate and temperature.
- Ironically, this can lead to settings that look reverse to their defaults. With the Infill being the slowest and your Outer wall being your fastest. BUT, that's only because we've slowed down the head speed of our infill. The rate at which plastic is being printed remains relatively unchanged if not increased. And in doing so we have stronger infill with better bonding to the previous layer along with fewer inbound stresses leading to less warping and greater strength and dimensional accuracy.
Starting from absolute ground zero, or annoyed with your results?
- Nearly every PLA will print at 190, punch that in along with 0.20mm layer height, 20-30mm/s and hit print.
- Part didn't stick? Slow that baby down to < 10mm/s. What's the hurry? Turn it down and get a good look at what's happening on that bed.
- Surfaces look watery and not smooth? You're too hot for your flow rate, turn that temp down by 5C and try again.
- Layers creak, corners curl up on even slight overhangs or off the bed without looking mushy? Might be too cold for your flow rate (you're are going slow right?). Up it by 5C and try again.
- It's up! My curling is WORSE! The layer beneath it hasn't had time to cool. Go lower. No improvement? Go lower and slower.
- Get a simple model you can print with sharp corners and a good looking top then start ratcheting up your settings scaling temperature and flowrate as affected by head speed, layer height, and trace width.