I’ve been printing for about 4 years now various functional parts to help out around the house when stuff breaks and when a niche is found. So I am not completely useless at creating functional parts but I have an issue.
I recently obtained an air conditioner from a company for free that was missing all its connectors so was just a heater. Adding some ducting and an adaptor and I would have a fully working air conditioner.
I created my model for my measurements and it fit perfectly. The problem was when i turned the air conditioner on. It is at this point i learnt of the glass transition (Tg) value of filament we use every time we print. This property (which i think needs to be boldly stated on packs and descriptions after this) is when the temperature at which the filament transitions from being solid to floppy (probably a better definition). Needless to say my print went floppy and failed. So I increased the thickness of the print wondering if it was because the adaptor was so thin. Nope that one failed too.
So i did some research on various forums from google talking about the same issues from other people. Two things were recommended to deal with high temperatures, colorFabb HT and PEEK filament.
I have replicated the thick wall variant in colorFabb HT and whilst better it is NOT high temperature enough for this application.
The air conditioner seems (thermocouple in vent) to be outputting 90°C hot air. So colorFabb HT apparently deals with <100°C which should work fine. It does not although it is very close.
I own a Lulzbot Taz 6 which allows <300°C which rules out PEEK.
Have you tried ABS? I am using a part I printed in ABS on the outlet of my espresso machine where the water exits at 91°C. The part has been in regular use for about 2 years now without issue.
generally polycarbonate should do well under 130°C, ABS under 100°C, but many filaments have lowered glass transition temperature for easier printing. Forget any PLA or PET(G) they will all fail at 90°C
In the meantime, try experimenting with different designs. Why not create some kind of double walled adapter with a thin-skinned inner component and ribs to a thicker, structural outer component - add venting around the outer component so it stays cool and provides the structural support to the inner part?
I have PLA printed pieces attached directly to my hot end that while being slightly warped, are quite functional.
This begs the question: where are the midrange plastics with higher performance than PLA, ABS, PETG? Our high temp hotend can do PEEK and ULTEM but they are so expensive. Does anyone see any “midrange” materials out there?
Brook
@Don_Moss I have not tried ABS as it is such a paint to work with. Your case gives me hope though as well as the Tg of 105°C although I heavily suspect that depends on supplier.
@Alex_Wiebe PETG has a Tg of 88°C so would be very floppy.
I have tried “designing” my way around it a bit with a double skin wall with vertical bracing between inner and outer. That was a particular disaster as both walls fail with the inner one basically just melting.
I cannot vent the design as that defeats its entire purpose of carrying hot gases outside of the cooling area.
@Josef_Jelinek Polycarbonatefrom E3D is doable but they don’t have Tg listed but other places seem to say 115°C which should be good enough. Really hate my heated bed in triple digits though.
Not a fan of allowing my heated bed to be near triple digits due to having my previous printers bed cause my house to burn down (design flaw by manufacturer). I don’t have that printer and this one is designed much better but still a bit sphincter clenching.
Just don’t do PEEK if you don’t know what are you doing. PEEK will release toxic smoke and its not home printer friendly!
Polymaker PCmax should do the job for you, its hard, strong with TG of 115C.
@Ritchie_Wilson I have done a lot of trial and error to get to a fairly easy and reliable printing process with ABS.
I use a glass surface with silicon pad heater, an E3D v6 hotend with a cooling fan but no filament cooling fan.
I apply some PVP (glue stick): 2 coats on a clean plate with time enough to dry between coats, or 1 coat on a ‘used’ surface.
Heat the bed to 75°C.
Heat the extruder to 235°C. (For my filament anyway).
Check the Z0 height with a sheet of paper: it should be able to be moved with gentle force.
Extrude some filament to get it flowing cleanly but don’t remove it from hanging from the hotend.
Start the print and as the hotend gets close to the bed remove the hanging extruded filament.
For small parts I arrange several on the plate to allow some cooling time between layers.
I will test greentec pro and pc max to see which is stronger. Then I’ll reach out to the manufacturer.
With our high temp hotend performing so well, I want to find the strongest filament at a reasonable price I can source that requires the high temp abilities of the high temp hotend.
I know this sounds like a scheme to sell filament, but’s it’s actually a pursuit to find or create a stronger filament that isn’t encumbered by the lower (less than 275C) temps of most hotends. I have to believe that a plastic with a higher melting temp enjoys a higher glass temp so it would perform better under high heat (not just sun, but heat from friction on nearby parts - like motors and electronics).
And ultem and perk are over the top due to price. We can print those but they are hard to print and so very expensive.
Anyone know of a plastic out there that hasn’t been tried in 3d printers because of the high temp requirements? We can go up to 450C.
We need a low melting temp metal that doesn’t pool, or go to dripping liquid when it hits a certain temp. Carl accidentally melted (softened) aluminum in a test once. We would be willing to design an even higher temp hotend as long as you stay below the temp where stainless steel gets soft. Our high temp is all metal- stainless steel. And we can use stainless steel in the tip as well as water cooled cold end. Just a thought.
Btw, the silicon on the fiberglass sleeves do break down after many hours of high temp printing… so that becomes a consumable if used.
Also interested in knowing if anyone has experience with fiber chop in plastics… large nozzles allow longer chop to be added without clogging the nozzle. Would longer chop produce stronger parts? We have 3mm tips coming… for use with 1.75 filament. You just bump up the extrusion flow and use it with spiral prints. I use a method in my model design that puts small gaps in the design that the slicer sees as gaps but in the real world, they fuse together as solid layers. So with much work, you end up with spiral-like paths (few or no travel moves) that keep the plastic from oozing like you will get with many travel moves in a layer prepared by conventional slicers. This results in strong parts w solid-like structure that you can print w really big nozzles.
Have any of you tried our NylonX? It’s remarkably strong and prints beautifully. Also, it’s got a 155C HDT, which is higher than PC or any filament I’ve printed with outside of PEEK.
