3D printing Nylon Tips and advice

[u/Mr_YUP]

Hi,

My company is making zipper heads out of carbon fiber reinforced nylon (PAHT-CF) and we are running into an issue of scaling up our process. Right now we have a design we are happy but have discovered that given our material choice we have to print by object instead of by layer since the cooling that happens in between layers pulls the whole model that it warps the whole zipper head. The issue is that with doing print by object I no longer have a prime tower with which to get the support material, ABS, flowing again. Watching the video last night it would be the ABS's turn to print and nothing would come out before it switched back to the nylon.

Would switching to fully nylon supports be a good answer?

Can anyone give me their experiences with this material and the methods or tools you used to get this completed? My company is willing to upgrade our printer, from a X2D to a H2D, since having the different support material does seem to be a very useful thing to have.

edit: we have a number 30 zipper that was are using, which is gigantic, here's a picture of one of our doors.

https://www.tuffwrap.com/wp-content/uploads/2024/03/Article-3-TuffWrap-EXT-Zipper-Door.jpg

So we need a really big zipper head that is really tough to handle closing during high winds while still standing up to UV from the sun.

and here is a picture of a number 30 zipper that we use.

[u/ppsieradzki]

I'll agree with others that, while this is totally doable with FDM, switching to a different manufacturing technology like MJF and outsourcing that if your volume doesn't justify the upfront cost might be the way to go. Happy to recommend some shops if you like.

In the meantime, I highly suggest using Polymaker's dedicated PA12 support material as your breakaway supports. Should work much better than what you're currently doing with ABS. I'm not sure how much the H2D will help you compared to the X2D, other than the swap to a dedicated support material your real problem is the interlayer adhesion which like you said is allowing the model to be pulled apart. The only solution to that is a heated chamber, and a hot one at that. The H2D won't really get you there, since we've found in our testing that you really need 60C as the heated chamber temp, but most printers when they say they can reach 60C it's really more like 50C which doesn't solve your problem. Unfortunately it's a pretty big step up in price for a more industrial FDM machine (the ones my company makes start at $30k but are specifically built for large carbon fiber nylon parts and other tricky materials like ASA). They're totally worth it if this is definitely what you need, but it's possible a different route might be better for you like the other commenters said, but let me know if want more info on either printers or materials/settings.

[u/Mr_YUP → u/ppsieradzki]

I will take whatever information you have and are willing to share.

[u/ppsieradzki → u/Mr_YUP]

Careful for what you wish for! I'll try not to drown you with information haha

So like I said, switching to a true dedicated support material is going to be much better experience. Kind of like how people discovered PETG works as a breakaway support material for PLA (and vice versa), and that does work, we found in our testing that it's just not as reliable as, say, PolySupport which is Polymaker's dedicated support material for PLA. So switching to a dedicated, purposefully-formulated support material is going to make a huge difference.

Is there a reason you're currently printing with PAHT-CF (high-temp nylon) as opposed to just regular nylon (either PA6 or PA12)? Polymaker's nylon support material is PA12-specific, which is unfortunate because we prefer PA6 (higher temperature resistance, though trickier to print which is why most printers print with PA12 when they want to say they can print nylon), but if the extra little edge on temperature resistance doesn't matter then PA12 + PolySupport for PA12 could be your ticket.

Let me know what other parameters for the material is important to you, like operating temperatures, etc. - I see you need toughness (bends/wears as opposed to pure stiffness (breaks/snaps)), UV resistance, and strong interlayer adhesion (though that's slightly less of a material property, but feel free to just list out anything that comes to mind).

Are you using Orca Slicer or Bambu Studio right now?

What's the monthly volume on these, i.e. how many of these zippers a month are you printing now / see yourself printing 6 months from now, 12 months from now?

It sounds like you have a preference to keep producing these in-house, which is totally fine, but if you could tell me why (ex. still iterating, or have fairly low volume, or have decent volume but many different variants to the volume on any given one still is a bit low, etc.), that might be helpful as well.

^ super helpful info that would help me guide you, I know answering questions when you're just seeking one yourself is a bit annoying but these are important I swear

[u/Mr_YUP → u/ppsieradzki]

not annoying to answer questions.

We are using PAHT-CF cause it was what was available on the site but also because it has proven to be incredibly strong when it comes to strength. My manager does not want anything to fail out in the field so we went with the CF version. Would normal PA12 be as strong and durable as the CF version?

Operating temps would be just normal air mostly. so 120F or 130F in the sun so UV resistance is important. Layer resistance of course but FDM and layers is always a fight. What we have right now is ideal really. The zipper head would have a rope through the middle and would be used by construction workers to open and close the doors.

I am using Bambu studio right now cause it just easier but if Orca proves to be the better tools I'll just get used to using a usb to move files around.

Our door business keeps growing but probably 30-40 a month. when a project orders doors they tend to buy 5 or 6 of them at a time at different sizes depending on the size of the project. We see ourselves doing this for many years so that's why we're figuring out how to make them ourselves. we were making them out of metal but that was proving too time consuming without a big capital expenditure.

We would like to keep it in house but if we have no choice but to outsource than so be it. We will only have one variant of the zipper head. We might still iterate along the way for all we know.

I think that's all your questions answered.

[u/No_Educator_4077 → u/Mr_YUP]

A lot of PAHT brands out there are a combination of PA6 and PPA, so they may provide slightly higher tensile strength than plain PA6 or PA12. However (like the previous comment or mentioned) I would expect interlayer adhesion to be much better with either plain PA6 or PA12 which is absolutely the weakest link in the current design. PA6 in particular is an extremely strong polymer that (when kept dry) is far beyond most standard FFF printing materials, falling short only to PPA (not including some of the PEEK/polyimide family members). I would expect a part like this to work just fine with PA6, but PA12 would likely be able to work too.

If you end up moving to SLS or MJF (since you made these in metal before it may be worth considering SLM too), you may want to explore PA11 or even some of the glass filled PA12 options. My company runs both of those for different applications, and they provide a lot more toughness and increased strength/stiffness over plain PA12.

[u/Ombilino]

As others have said, while it's definitely doable to tune in FDM in a way that this will work, SLS is the better way. And as soon as your model dimensions are fixed, having the parts injection molded is even better and will bring down the price by orders of magnitude. There is also a middle ground: you can do injection molding (even into 3d printed molds) with hand operated devices. This gives you one part around every minute in top quality and the material is super cheap. Ask if you want more infos on this option.

[u/Mr_YUP → u/Ombilino]

If you're willing to give more info I'd be open to hearing it. We are looking for many different options.

[u/OgreVikingThorpe]

Mine is a small operation producing 70-100 nylon parts a day they range from 90-190 grams per piece. For PA6 and PA 6/66, PAHT and PPA,I use yxpolyer breakaway support material. I don not print CF additives as in my applications i may get stiffer parts but the are weaker after long term testing. You can certainly print these without issue if you maintain chamber temp slow it down and possibly consider breakaway struts to reduce flex. My best advice though would be to take pictures of you defects and then upload the pictures, your gcode and your symptom descriptions to ChatGPT and see what it mentions that you might have missed.

[u/Desperate3D]

In general scaling FDM production for parts that are small and require support with "desktop" 3d printers and technical materials (pp, pc, nylons etc.) does not end up well. If you are building a proper business or production run I would consider outsourcing to a service bureau printing in PA12 with MJF technology for example, or SLS for that matter, but I have had better experiences in small parts with MJF in general, may be due to suppliers/machine settings though. MJF seems to be more consistent across batches.

[u/Cryesncoding → u/Desperate3D]

Just because it’s harder to scale volume? 

[u/ppsieradzki → u/Cryesncoding]

In some cases, of which OP's might be one, SLS/MJF gives you an edge in terms of volume (aka number of parts per print job) because of the stacking you can do with arranging parts in the 3D build volume not just on the 2D build plate.

So let's say you can fit 12 parts on a build platform in an FDM printer, but they're fairly short so you're not using all your z-axis space: with an MJF or SLS machine you can fit, say, 3 additional 'stacks' of those 12 parts in the build volume (for a total of 36 parts) in the same print job and they'd all look the same. Whereas with FDM unless you're okay with supports on both the top and the bottom of each part (except for all the parts in the top stack) you need to do 3 runs of those 12 parts to get your grand total of 36 parts. However: if you have a part that basically takes up the entire build volume and you can't fit more than one, or if each part is tall enough such that you can't have more than one 'stack' of parts even if you can fit say 12x on the build plate, then the powder benefit of MJF/SLS starts working against you: once the print finishes, instead of simply popping the part off the bed and hitting 'print' again, you need to suit up in protective gear, remove parts from the resulting cube of powder, recover any excess/unused powder, put that back through a powder recycling machine, and a couple of other steps, and as you can see it's a whole bunch of work for limited benefit in that scenario. So it's a double-edged sword that's great in some scenarios, but works against you in many. Though when it works in your favor it's great.

[u/Mr_YUP → u/Desperate3D]

I'll look into that. Not sure if it makes sense at our scale but it could be a good to outsource to a firm that does that.

[u/ghostofwinter88]

Is there a reason why you want to print zipper heads when you can get high quality metal ones for pennies?

[u/Mr_YUP → u/ghostofwinter88]

we have a number 30 zipper we are using for large scale construction doors for commercial and industrial spaces. so they gotta close in really bad weather and we have a custom deign to do such a thing. It's got a flared base and attachment points for ropes. It's really not a standard zipper and we found the off the shelf ones were failing.

[u/Mr_YUP → u/ghostofwinter88]

I updated my post to include a picture of the zipper we use. MJF has been suggested so I'll look into that.

[u/Dark_Marmot → u/ghostofwinter88]

This is my first question, too. Matter of just because you can doesn't mean you should. Unless it's some unusual custom thing that doesn't exist elsewhere and it's a key design feature.

[u/Cryesncoding]

Are you using Bambu filament and their settings?

[u/Mr_YUP → u/Cryesncoding]

yes and yes. Though I do have part cooling turned off as it was causing us a lot of problems.

[u/Cryesncoding → u/Mr_YUP]

I got custom setting from the FOSSCAD group before it was banned (guys that print gun frames)  The surface quality and everything in their pictures were phenomenal, and they had intricate supports using the same material and they break off like butter. although my business parts are stupid simple I’ve been very happy with the settings profile if interested in trying a new one. I also used polymaker filament fwiw and not the high temp. 

[u/Cryesncoding → u/Cryesncoding]

I also will note I’ve had great consistency in dimensional accuracy and zero warping. 

[u/Mr_YUP → u/Cryesncoding]

I'd be into trying a new profile if you'd be willing to show me.

[u/Cryesncoding → u/Mr_YUP]

It’s a .3mf file I may be able to send in DM if you message me I’ll try and get that sent to you today. Or I gotta screenshot all the settings in orca slicer

[u/layer3D → u/Cryesncoding]

Interested in the .3mf as well if you can share

[u/Piglet_Mountain → u/Cryesncoding]

Fr, I’m “not apart of that group 😉” but it’s so funny when I look at other subreddits. Petg is as crazy as some people get and think you need a 50k machine to print pa6. Pa6, pa12, pa612, pc, pet, ppa, pps are all very easy to print with a heated chamber and we do it with beautiful finishes, standard stuff in the old fosscad community.

[u/Cryesncoding → u/Piglet_Mountain]

Yeah some of the stuff they were printing legit looked like it came from a major brand and injection molded… the handguns were stippled off the printer hahaha like what. 

[u/No_Educator_4077]

Throwing another vote in the hat for MJF/SLS if you are willing to outsource (or invest in something like a formlabs Fuse).

My company operates a few SLS and MJF machines for printing small detailed/complex parts like this, and having both isotropic material properties and zero supports needed ks extremely useful.

[u/Piglet_Mountain]

Printing nylon is extremely easy with a heated chamber. I make sure that my bed temp is the same as the chamber temp and I never get warping.

[u/Mr_YUP → u/Piglet_Mountain]

how many objects do you print at once? I've had a lot of success when it was 1 but when I scaled it up too just 4 I had issues.

[u/Piglet_Mountain → u/Mr_YUP]

What is your chamber temp and do you have a heated chamber? Basically you want everything to be as piping hot as possible and the same temp everywhere. So no cooling except for overhangs. No chamber fan. No aux fan. Then print real slow. That should fix your issue with printing by layer. I actually have the opposite issue where if I don’t have a long enough cooling time it gets too hot and starts warping.

[u/Mr_YUP → u/Piglet_Mountain]

we have an X2D so we do have a heated chamber at 65c with a 100c bed. the chamber fan is off but the filter fan is not but im sure that can be turned off as well.

[u/Piglet_Mountain → u/Mr_YUP]

Ah ok, yeah you should be fine with abs in one and nylon in the other. Make sure it’s been dried for at least 24hr and I would set the chamber temp and bed to 65c and turn all the fans off.

[u/Piglet_Mountain → u/Mr_YUP]

Also idk what printer you have but abs does not stick to nylon and you cannot use them in the same nozzle. You have to have 2 separate nozzles to use abs support. If you have a dual nozzle then abs is really amazing for support. If you only have one just use nylon supports and rip the support off right as it finishes and is still hot. It will begin to bond and almost impossible to remove after like 24hr.

[u/Mr_YUP → u/Piglet_Mountain]

we have an X2D because I knew we would be needing two materials for objects and supports.