I’ve been printing PLA for over a year and have never printed any type of TPU. Recently I found a model which requires both PLA and TPU 95A (6mm of TPU is printed first and then the remaining is PLA).
So, my question is can I print both in same job and have them bond together OR do I need to print both individually and the glue them together?
This depends on how the model was designed.
Being able to print with two different materials at the same time and as easily as the H2D can (you indicated you have that model), is relatively new. As such, nit many models take the opportunity into account.
Assuming this one does and the designer understood the inherent issues, you should be good.
If they were not sure, it might work, if they have no idea, good luck.
As the owner of a H2D you are able to use things others are not, so you are leading the way.
You would use one nozzle for the PLA, and the other one using the appropriate inlet for the TPU 95.
These two materials do not bond well together naturally. If the designer knew what they were doing they would design in how the materials marry, using one of two techniques or a combination of both.
- Designed to fit together.
The designer models the PLA parts and TOU parts to fit snuggly together utilising joints that keep the two materials bonded by friction. Think woodworking interlocking joints for a reference you may already understand.
- Beam Interlocking
This is the name for a slicer option, that when enabled, creates a pattern of one material and the other starting before (lower layers and higher layers) than designed in the model itself. As the slicer knows where each material type is used it essentially builds a mesh of each together as the model is built up. Think interlocking your fingers, but there are thousands of tiny fingers grabbing both materials p.
@MalcTheOracle … first, much thanks for the detailed explanation. It was very educational. The specific print I am referencing is on MakerWorld: PinHoist
From what I can view after downloading the 3mf, there is not a joint or interlocking feature. So, I assume I would glue the PLA & TPU parts together (the designer did not provide much detail in this area).
You are welcome.
It looks like it is designed to be printed as two different parts, a traditional model that benefits from two materials used together rather than printed at the same time.
It looks like friction is used to keep the two parts together using the indents at the end to slot the TPU elements into and then when in use the TPU will be pressed to the PLA. Glue will not hurt, but may nit be needed.
Make sure you print the TPU using the TPU inlet in the back of the printer.
Use this wiki article for those instructions as you haven’t done it before. Be careful to focus on 95A as instructions for each type vary.
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Thanks again for explaining and recommendations… off to read the link before I get started printing the design.
@MalcTheOracle … quick question about the different TPU filaments offered by Bambu. Since I have an AMS HT & AMS Pro 2, would you recommend I use the TPU for AMS over the TPU 95A?
TPU for AMS is a more rigid, less flexible variant TPU. It is basically 68D.
So the choice depends upon your requirements for the TPU.
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Only thing I would worry about is, sometimes when using tpu as the base, it allows the upper portion of other material to warp.
If in the future, you decide to try them in one print
Ive never had an issue with them not bonding. It also likes petg and abs. I do know its a known issue with pla, just never experienced it. When using pla as support for tpu, you cant do zero gap because they will bond if you do.
Now that I think of it, we print them both at the same temp these days. Maybe why it works better now.
Apologies, I sleep occasionally.
TPU is a family of flexible materials based around a shore scale. This denotes the point between very flexible to rigid that it appears.
TPU 95A is the most common one 3D printers have had access to, it was been the easiest to print while still being flexible ^.
As noted above, TPU for AMS is shore 68D, thus is a harder material when printed and essentially designed to be able to be used with the AMS while still being in the flexible family.
Recently 85A and 90A were made available by Bambu Lab, although available by others before.
These are much softer and harder to print for novices. (See the guide I gave you the link above for).
Which you choose defends on your requirements.
I like TPU for AMS, it works well in the AMS, lets you easily mix colours within the same filament, but, it is stiffer. Works well for coasters as it can still be bent over than size.
Using TPU is all about how you design the flexibility in to the design. Wall counts and and infill percentage are key to having something bend or retain more rigidly.
TPU for AMS will be much more rigid to start with and be hard to get to something bendy if it is thick.
The key is experimenting until you are happy.
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That info was invaluable, can’t thank you enough…
I’m in the process of designing a object, for a friend, which will go on the bottom feet of a pinball machine. The first 6mm of it will be TPU to keep it from sliding on the floor. After reading your link, watching videos on TPU 95A and TPU for AMS, my first print will use TPU for AMS because of the effort & difficulty of TPU 95A. I hope it works because not very confident in my ability to print TPU 95A.
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We are all idiots until we try. I have tremors, thus makes handling different material even harder.
Yet, I have done it and use it a lot.
I have TPU for AMS, 95A, 90A & 85A (the most annoying for me to use).
I have made a lot of things in 95A, keychains, brackets, toilet seat bumpers (those rubber feet on the seat and lid), even more recently for CyberBrick models, particularly tyres (tires for Americans who don’t write English).
As long as you load it correctly, it will print easy enough. It sticks really well to the build plate and removing takes a little effort even when the build plate has dried, so no adhesive issues to be concerned about.
Experiment as you will open up a new world of possibilities.
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@MalcTheOracle … I have my AMS HT & AMS Pro 2 on a riser on top of my H2D. My biggest resistance to printing 95A is time/effort to remove everything above the printer in order to feed 95A in from the top. Curious if you feed 95A from the rear. If so, any advice on what to do & what not to do.
I do not have the H2D, but have read up on it lots, particularly related to TPU usage.
There is a dedicated port on the back, although it isn’t that easy. This inlet port is designed to make it easier to get the TPU into the print head easier, by changing the and shortening the travel path.
Unfortunately there is another task to achieve inside the printer. You must disconnect some PTFE and redirect it.
This solution is well documented in this article, just scroll down to it, it is where I “borrowed” the photo used above which I marked up.
https://www.fabbaloo.com/news/hands-on-with-the-bambu-lab-h2d-3d-printer-part-2
Ok thanks… I’ll check on using the port on the back
I have completed multiple prints with PLA/TPU in the same object. As long as you use proper beam interlocking, it will work just fine. Just make sure that the model is sturdy enough so it doesn’t wobble during the print phase, since that will ruin your experience.
I have tried as low as TPU 65A with PLA and it works just fine, but as always, make sure your filament is dried and calibrated correctly beforehand to maximize your success rate.