Tips for TPU?
Tips for TPU?
I just use my textured sheet and remove very carefully - but I tend to use harder TPUs which makes flexing the sheet more effective.
I have heard people say that TPU is the reason they still keep a glue stick handy and the Prusa material matrix says to use it on their smooth PEI sheet. And it suggests a polypropylene sheet is also applicable without glue stick.
This is the first time I’ve had this much issue removing a print.
I knew it would stick fairly well on the textured PEI, but this was a whole new level. A bit surprised I didn’t peel it, to be honest.
I’m leaning the same direction as those people: Buying a stick and keeping it around for those few times I do use TPU. PETG and PLA is still 98% of what I print, and they both come off easily on textured and PLA easily on smooth.
The question I’m stuck with though: Textured with glue or smooth with glue for TPU?
Smooth prusa powder coated works great.
Drying makes a gigantic difference. It only takes around an hour in the open before TPU changes significantly from any ambient moisture and become visible in the print.
If you can control the moisture to a minor degree, you can alter the mechanical properties significantly. Once you hear popping, you’ll likely start blowing holes in prints, but there is a stage before this where the bubbles of gases are present but are not coalescing into the larger audible voids of escaping steam. You will see this on long prints using dried TPU filament left out in the open. There will be a much tougher start to the print that gradually degrades into a slightly softer and more flexible texture. It will likely turn slightly foam-like spongy rubbery soft for a section and then it will start popping and dropping walls with holes in the structure.
If you write down the room temperature and humidity and note the time it takes to get to this moisture property, it becomes possible to alter the flexible properties or empirical hardness of a TPU to make it behave in off label ways. This is essentially creating your own rudimentary foaming or light weight filament. It works best for vase mode or other small single wall structures. I have used this based on intuition alone. I imagine with a bit of record keeping one could control the humidity of a box to do longer prints within this state of foaming softness. I don’t know of anyone using a humidifier like the ones for acoustic guitar cases or cigars in a filament box, but that would be an interesting thing to play with too.
Wait what?
The freezer trick I’ve heard of, but baby powder?
Applied before printing then, I guess?
My printer is enclosed and I’d wory about the aux fan blowing it everywhere.
Even with 0% fan for first layer, I’d never be able to perfectly distribute it under only the print…
I see many use glass still. Old school way of doing it, but if it works then I guess it’s good!
I’m mostly leaning towards smooth PEI with glue for my next print. Hopefully that will be better than textured with no release agent. Fingers crossed and thanks for the feedback!
Yeah you’re probably right. Different blends give different results.
Thanks for the filament advice. I try to purchase as locally as possible, but Geeetech is not etched into memory as a no-buy ABS!
Thanks for the advice!
I ran a cold bed this time, but I’ve seen some say warming it up for removal also works.
So many things to test in the future!
Turn off the heat on the hotbed. TPU doesn’t need it, and it makes removal much easier if you don’t heat the hotbed.
Also reduces the amount the printer heats your room by 90% or so.
You have my deepest condolances.
Come to the Nordics for a coolcation next year, but stay safe untill the heat wave passes my friend!
In my experience, TPU benefits from a higher first layer - it prefers being just “deposited” by the nozzle instead of slightly squished like for PLA and PETG. You can try raising your Z adjustment by 0.02 - 0.05mm and see if that makes it easier to remove.
If you work with transparent TPU and don’t want it to turn white, print slow and cold.
I don’t print TPU on a textured bed. I use the flat side of my build plate, which I also have coated with a giant sheet of Kapton/polyamide tape. Peeling the completed parts off of the smooth surface has never been an issue.
A word to the wise: Always run with a sheet of polyamide tape if you have a flat build plate. This will go a long way towards protecting the finish and flatness of your plate, and I have definitely saved myself a couple of times when having a Z offset that was too low and thusly crashing the nozzle only into the tape and not the surface of the expensive plate itself. You can apply adhesive and clean the tape’s surface just the same as the PEI surface of your plate, but once it gets worn out or chewed up or otherwise no longer produces parts with a pretty underside, you can just peel it off and reapply. If you’ve already fucked up the surface on your plate you can also paper over this with a layer of tape which will smooth out small scratches, pock marks, and other imperfections.
And if you really need to employ the nuclear option to get a stuck part off of your bed (i.e. if you’ve printed something with a sticky filament such as TPU or PETG and happened to have your Z offset way too low) you can peel the tape off along with the part. The tape is unlikely to survive this process, but a pack of 12 sheets is only $20 or so.
Appreciate the insight mate! Much appreciated!
Tape seems to be a cheap way some of the “older” guys run with, so I have to test it at some point.
I have been printing a lot of tpu the past few weeks. I’ve been using magigoo glue stick. I have no idea if it’s the best because it was a random YouTuber recommendation. But it’s been working.
I’ve been using Anycubic TPU 95, Esun foaming TPU, and Variosure foaming TPU on textured pei plate.
I’ve been trying to get a hold of Magigoo for TPU, but it’s chronically sold out locally.
Have you tested it on smooth PEI, or just textured?
Appreciate the feedback!
Still haven’t been able to find any Magigoo, so I gave it a crack and it worked like a charm!
Thanks for the advice!