Threaded Holes & Inserts | Design for Mass Production 3D Printing

[@idaner]

I'd love to see videos about lids, hinges and latches (basically boxes). Your videos are always very informative and I find that my own designs are often lacking in those regards.

[@slant3d]

Good Idea. Will do

[@ecsyntric]

never has a video made so much sense in under 7 minutes

[@terryevans1976]

I always learn something from these. Thanks for putting the effort into them.

[@AerialWaviator]

Great tips, particularly the thread cutouts design tip (5:40).

[@AbdurrahmanAllahem]

Thank you. I really enjoy your channel. I rarely watch an English video till the end. But with you, a piece of cake!

[@slant3d]

Wow, thank you!

[@GiulioVonKerman]

Just what I needed for my project! Thanks!

[@slant3d]

Glad we could help!

[@yayinternets]

Great entry to the series as always! An entry I’d like to see: how to design parts that are designed to be separated. An example: A small wall mount that is designed to have a removable bin attached to it. Like a bin that could hold a bunch of wood screws but removed to take to a work area. Another example: how to design parts that are too big to print on their own but can be broken out into several prints and then adhered together afterwards with epoxy. Like if you were trying to design a trunk lid spoiler for a car for example.

[@shaynegryba]

Awesome video! I’m going to try out that thread wedge removal technique. If you’re looking for future video suggestions, I would LOVE a video on joining parts together for both strength and precision. I’ve been going back and forth between adhesives, welding, and fasteners for a while now and would appreciate you guys weighing in!

[@mcdodge6679]

i find it very very nice to use what is effectively 2 parallel hinges that interlock with another 2 hinges of a printed part. That way when you secure both hinges no movement is possible. This works very well with the use of paper clips as the hinge axle as they can be easily secured and are quite durable. I like to use this quite often with Size #1 paperclips inside of 1.1mm to 1mm holes depending on tolerances. It's cheap, effective, durable, not hard to print, and only requires the straightening, cutting, and placement of paperclips. Probably not the best for making millions of a product but it works well for me.

[@patricktierney4392]

I would imagine that if you really wanted to make a lot of them, you would use a spool of some kind of wire, or get metal rods and cut them en masse.

[@mcdodge6679]

@@patricktierney4392 yeah probably, would definitely cut down on a majority of the post processing, would also let you be more specific with the actual diameter of the wire used and of your hinges for smaller or chunkier builds. for me though it's just easy enough and works well enough to grab a cheap box of paper clips and use them.

[@phasesecuritytechnology6573]

Is there a video on this?

[@mcdodge6679]

@@phasesecuritytechnology6573 not really as far as I know, it's just a simple solution I figured out one day and use often

[@mistaecco]

The most obvious solution that nobody seems to ever consider: self-tapping plastic screws! They're not optimal for something that needs frequent disassembly, but if you just need to join two parts, it's so much simpler!

[@slant3d]

Mentioned in the video in the first example. ;)

[@timbalandtimbo2190]

very helpful video, many thanks! You got it to the relevant points!

[@alaingrignon]

That threaded cut out idea is brilliant. I would have been afraid it might lose strength but glad to know it’s not the case. Always looking for ways to build more efficient prints, thanks for these videos. I would be curious to know though, from your perspective, to manufacture products with parts that need to be fastened together, what is your preferred option. Threaded holes, inserted nuts or simply snap fittings? That is for parts that just need fastening together, not necessarily high strength requirements.

[@slant3d]

Check out our Joining Video

[@josephpk4878]

A good tip from Slant 3d - one that I frequently use - is adding a taper to the top of my vertical holes (teardrop shape), to avoid sagging top layer sagging inside the hole. I generally end my hole sketch with 2 lines at 100° that create a peak on the hole - works great and thanks.

[@TheSupertecnology]

Stefan from CNC kitchen has a video in which he tested the strength of heated inserts against screwing into the part directly, and heated inserts are basically overkill for most screwing applications with 3D printed parts. Inserting a nut so as to have embedded threads is also a good idea, except for the part (no pun intended) in which one basically needs to be babysitting the print to pause and insert the nut.

[@deafengineer]

Very cool video. I can't believe Ive never considered that nifty "cut out the threads" trick you showed. I'm partial for the inserts/nuts depending, but for big stuff that opens alot of doors design wise

[@slant3d]

Glad it was helpful!

[@deafengineer]

@slant3d Thanks man! Hey, yall wouldn't need an Mechanical Engineer, would you?

[@goury]

I see you're getting better at this. I approve this one, good stuff. As for the snap approach, I myself some times do "double self-locking snaps", it's a snap with another snap that snaps into snap, locking it from ever unsnapping. Since the inner snap is hidden inside and the outer snap is locked from unsnapping from the inside, there's no way it can ever unsnap, creating a very easy to assemble and also reliable joint.

[@deandavies1462]

Ive recebtly been developing a product that has magnets imbeded into the printing process. Theres someting very satisfying when an item is intergrated into the printing process and is invisible once the print is complete.

[@slant3d]

Sure is.

[@bricoschmoo1897]

Hi! Been devouring your channel when I have time for a few weeks now. Love it ! Thanks a lot for all this knowledge you provide :D That embedded nut technique would be amazing for a project I have. Of course it's not really scalable, but that's not my goal here.

[@madetofit24]

We've learned that square nuts work better than hexagonal ones when embedding them. Moderate torque and the hexagonal ones can slip and turn even with a tight fit because plastic flexes. Square ones do not.

[@Davids3DProjects]

I love these tips,. They are very helpful. Thanks.

[@slant3d]

Glad you like them!

[@skaltura]

I have done routinely printed M3 / M4 threads, no issues there at all. Then again, since machine time is not so important for me, i tend to print LH of 0.05-0.12mm. These were done with mostly stock Ender-3 (Quality of life upgrades only; Filament guide + fan guard)

[@slant3d]

Vertical that is fine with high resolution. But nozzle size prevents it in the horizontal

[@nicholas_kujawa]

One method I've used for plastic threads in a printed part is this: Undersize the hole in the design process (eg. 3.75mm dia hope for an M4 screw). Get a length of threaded stock (M4) in my example), or cut the head off of screw, to use as a tap. Put the length of threaded stock into a drill set to low speed. Optionally, lubricate the threaded stock. Using a butane torch lighter, preheat the hole. Less is more. Then use the threaded stock in the drill as a tap. Gently apply pressure run the drill very slowly. If it binds up, back out, reheat, and repeat. This is a quick and dirty method that has worked well for me. Also if the hole is too big, snip a bit of filament and put it in the hole prior to preheating to resize the hole while threading.

[@jbradleyk]

I will sometimes print the hole undersize and use a tap to form the threads like with metal. It's much stronger than trying to print threads or letting the screw cut its own threads. For something more rugged I use heatset inserts but they of course require you to have a soldering iron handy and have a bigger keep out area around them.

[@slant3d]

That is also a good way. Tapping is great.

[@Vindolin]

I almost completely stopped using metal inserts and usually just use a thread cutter now. The force needed to rip out the threads is almost the same as for ripping out the inserts.

[@jbradleyk]

@@Vindolin Today I tried to rip a pillar with a M4 thread out of a PETG part that I'd tapped, the whole part was flexing and felt like it was going to break while the threads held strong, I stopped before breaking the thing.

[@tallAldiProduction]

I think it depends on the size of thread In my experience M5/M6 and upwards are usually strong enough to be cut into the plastic, for M4 it really depends on your sensitivity/experience when tapping and fastening your screws to not over tight, everything M3 and smaller I use heat set inserts as my failure rate with tapped hole became too high And it also depens on how often you will thighten/loosen your screw, if you just screw it once and never touch it again, tapped holes are probably fine, if you plan to disassemble your part often heat set inserts are far superior as the pratically don' wear

[@dekutree64]

@@tallAldiProduction Yeah, fine pitch tapped threads like m3 wear out pretty quickly in PLA. I use coarse threaded self-tapping screws, and haven't worn one out yet.

[@stuartandrews8161]

Can you do a video on the strongest glue up joints for parts that are too big to print on a build plate and have to be spilt up? Or maybe the various ways to split and reattach them where the joint will last long-term.

[@georgestone8099]

Always use square nuts if you're going to embed them. Much more resistant to torque, and way less likely to ever rip through the plastic and spin. Where I can, I don't bother pausing the print to insert them. I just use a cut out that goes to the face of the component if that makes sense. Then I just slot them in, and push them down until they're in line with the hole. I will design my products, so that the holes where they're inserted end up hidden.

[@heavyweather]

How would you go about that if you want to print a siphon...my Ikea Atlanta just broke because it's made of shitty plastics and the screw goes directly into that in the middle from the sink. The whole screwhole is raises in the middle but so weak that it breaks. I want to print a better version from ASA or ABS .

[@georgestone8099]

@@heavyweather I'm afraid I don't understand. I am not sure what an ikea atlanta even is. Sorry I can''t be of more help

[@dekutree64]

Great idea. I've used the nuts-in-slots technique before, but always struggled with tolerance. Square nuts would be much more forgiving. And better for embedding too, since the top will be flush with the print surface after dropping in, unlike the hex nut at 2:45

[@stevekay6895]

I would say that using a drill tap with a slow steady turn is the best. I've shown on my channel Caps that I've made for vape pen cartridges and they use super fine threads that FDM can't quite replicate. Great Video :)

[@molotilkin07]

Could do a video on practicality of non-planar fdm and the state of in 2023?

[@adamsvette]

How do you calibrate the printers when you are building a print farm? You must have a fast and accurate calibration method to use so many machines and filaments. Very interesting topic to me. What is the tolerance and dimensional accuracy you advertise/produce? +/- what?

[@YigalBZ]

This is a great video. I use inserts, yet the idea of embedded nut seems to be better. I need to try it out. How about hiding the screws from the top? Any idea how to make it look better?

[@Kopfballmagnus]

How does Slant do nuts inserted into the print? Robots or is it just a Person inserting them?

[@marshallb5210]

someone goes balls deep

[@raf_the_riffer]

@@marshallb5210 nuts deep, rather

[@anthonylaiferrario]

Nuts deep…

[@jaredupchurch7819]

On most slicers there are built in features that let you pause print at a set height or layer, allowing you to drop parts in. Then you can resume the print to let it print over the dropped in part.

[@AerialWaviator]

An option is a slit on the part where nut can be dropped into place post print. A good solution if the slot is on the bottom, or hidden area of a part. Another option is two parts that snap/twist together hiding the nut.

[@daliasprints9798]

I find threaded holes in horizontal orientation come out excellent without omitting top/bottom thread. It may be dependent on having adequate cooling; however, the thread structure tends to make the overhangs less challenging.

[@jowjor]

If I need a reliable threaded hole, I either use a heat set insert, or I print a round (or drop shaped) undersized hole with enough walls to be strong at the final size, then I drill to size and thread it with a tap. But I don't do high volumes. The other option is to direct thread into a smooth hole.

[@manuelmedels2624]

When printing holes on the side of a 5 started to add what is basically a triangle coming out from the top of the hole (like a teardrop). In order to eliminate the overhang. Just another solution

[@Enthcreations]

Useful 👍

[@brssnkl]

Is it theoretically possible to add plastic inserts into a 3D print like that metal nut? How would the adhesion work?

[@rolmie]

For embedded nuts, maybe take a look at square head nuts DIN 557, DIN 562. Rumor has it that are able to take more torque.

[@bangdollarsign]

I'll have to try the flange nut, I absolutely hate pullout

[@doodle4532]

Is there a rough time line for the Etsy integration to have other materials, specifically tpu?

[@Sembazuru]

Another way to embed nuts into a part is one of the ways that Prusa does it. Design a rectangular slot that intersects the machine screw hole for a square nut to be inserted into the part during assembly so you don't have to pause a print somewhere buried in your printfarm.

[@slant3d]

Also a reasonable way to do it

[@BlueThunder05]

What tolerance differences would you recommend when trying to use McMaster Carr faster models to create holes in parts?

[@adamuadamu5081]

2:55 Can confirm. Its effectively impossible to pull out of a good hole.

[@madelinemakes123]

Plastite screws are amazing for printed parts where you don't expect to disassemble it often

[@Toni5tark85]

How would Slant join box type parts that might be too big for print bed? Example, 10mm thick walled box that's a long rectangular in shape and needs to be printed in two halves. No lid

[@sixtysixstyx]

I reckon at @2:40 the print shouldn't be filling the interior of the nut no?

[@byroboy]

I'm surprised no one mentions using a coarse thread. If you have the opportunity to use a coarser version of the same bolt it will reduce tear-out and act almost like a wood screw but, when done right, I get way more reuses before it wears out. Not necessarily as good as metal on metal but much cheaper.

[@Etrehumain123]

Very smart !

[@slant3d]

Thank you

[@VictorGallagherCarvings]

I use both threaded inserts and nuts. But I can only use the nuts in the horizontal plane. In the video you are inserting the nut in the vertical plane. How do you keep the print head from colliding with the nut ? Am I missing something ?

[@dekutree64]

It looks like the pocket is deep enough that the top point is below the surface, so there will be some small voids in the final part. A square nut would be better. Or you could add some custom gcode to squirt plastic into the voids.

[@walid4337]

Well to be clear Over molding is a thing Where nuts are inserted into an injection mold And plastic flows around it We made quite a few of them and they work perfectly 3d printing is one way of doing it ,but isnt the only way

[@3sotErik]

@2:41 I don't think that example is quite what you meant. 😜 Not quite the slot/pocket you were going for.

[@PhilippBlum]

I just create small holes and push a heated screw into it. Once you screw it out, there is your screw hole. Pretty much the same as heated inserts, just with a screw.

[@benkeller3]

I would like to see something on multi materials. How can i add a TPU surface to a PLA base. Something like a soft face on a bolt used as a clamp. Can you figure out how to do this with a single nozzle machine. Thanks... Like your channel.

[@AerialWaviator]

One way is to print the two different materials as different parts, as they require different print temperatures. Designing the parts so they snap, or fasten together would be the easiest solution. Note: it's not often that a material change occurs at a single layer height boundary across a full part, so this would require multiple filament changes (and purges of the print head), or a printer that can print with multiple filaments unattended.

[@benkeller3]

@@AerialWaviator I agree with exactly what you are saying. I was thinking about a mechanical ways to do it. The only good way would be to use a multihead machine like Prusa XL. That way nozzle temps and all the other issues would not be present.

[@jeepxj]

I have really good luck with small machine screws that has a type F tip. it cuts in as you assemble.

[@larrybud]

2:50 was this a real design? How is it possible to put a nut in this orientation without the printhead crashing into it?

[@3sotErik]

What about PLA Goop?

[@mv2woods]

I don't understand why more people aren't talking about using screws designed for thread forming plastic. Works great and you see them in just about every injection molded part. Why fiddle with threaded inserts and captive nuts when we have a great solution right in front of us?

[@donald1792]

threaded inserts are obsolete to embedded nuts? thanks!

[@yayinternets]

Not obsolete, they have their place. Just not as durable, more likely to cam out.

[@aware2action]

You missed the helicoil inserts for ability to add tiny screws, with almost the durability of metal threads.❤👍

[@christianbureau6732]

Thanks

[@slant3d]

No problem

[@arnoldmarcus3634]

A wood screw into an smooth hole will cover most needs.

[@jameslmorehead]

I prefer 30 degree trapezoidal threads. With a minimum diameter of 6mm, I can print both the male and female threads no problem on an Ender 3 V2 Neo

[@slant3d]

Yes. The design of the threads is absolutely also important when they are necessary

[@sethjones5250]

So exactly how should I design a hole for a heat set insert? You didn't really cover that. The application I have in mind isn't really high stress, it's for a retaining screw for a cover.

[@treborrrrr]

Today i learned that overmolding and insert molding are technologies that do not exist. Who knew!

[@BTom16]

Snap fits allow me to extrude plastic parts and end up with wood.

[@seelyw.4818]

1/8 inch = 3,175 mm

[@slant3d]

You can round to 3mm

[@seelyw.4818]

@@slant3d thank you for your valuable content I learned a lot! Greetings from Germany!

[@TS_Mind_Swept]

"Pullout is impossible" oh I dont know about that..6.6

[@tjstrongbone5373]

Drop the nut in and around 2:42, the printer magically prints thru the nut. That is some custom printers you have there. Or wait 3 seconds for the real print and no magic 🤭