Being a mechanical engineering researcher myself, I absolutely love how accurate your experiments are. Not only do you try changing one variable at once, but you tell us where errors may come from. However, I'd really be even more impressed if you could formulate your experiments mathimatically so that, given any set of variables, you could find the maximum allowable stress.
The ratio of time needed to end up with an 11 minute video must be at least 100:1. Just to do the engineering and get the raw footage. Even more after editing. I'm certain there are very few Creators who have so much hard work behind each minute of video.
@@dmail00 Actually, a beam type torque wrench can be very accurate for this kind of thing. Typically better and more repeatable then a click type or electronic.
@@rotorblade9508 Not if you use a proper screw with threads designed for plastic. I don't get why people use machine bolts in 3d-printed objects as they are designed for metal threads. There exists such a thing as screw designed for plastic. You can get these for free from any broken appliance with plastic enclosure. Easier to use, better grip, and no need for threads, just a suitably sized hole.
@@ilkkavierula6664 The screws designed for plastic work great in applications where you screw it together and then never take it apart. Since these screws are designed to cut threads, if you remove them and put them back in, it's very easy to accidentally cut a new set of threads instead of screwing into the existing threads. That is a recipe for stripped threads. On commercial products, you often see thread-cutting screws holding most things together, but then a threaded insert and machine screw on things like battery doors that get repeated use. If you are able, you should have both thread-cutting and machine screws on hand and use the best screw for any given job. If your screw variety is limited by space, budget, or other factors however, I would consider machine screws to be more versatile.
@@jcon6734 Most of the time they settle on the existing threads. Especially if you start screwing with light force without forcing it (as you are supposed to do with any screw). Even if the screw cuts multiple threads it doesn't significantly weaken the holding power of the screw. This is due to the mechanics of how to screw works. The factor determining the holding power of screw in material is the shear strength of the material and screw threads. The variable determining the shear strength is the shear surface area and shear strength of the material. The amount of material removed by the thin thread of a plastic screw is so little it hardly has an effect on the shear surface area, thus the effect on pullout strength is very small. It can be a bit counterintuitive, but you can try it yourself by screwing a piece of wood to a phone catalog or old book. It will hold there very firmly even though there are hudreds of "threads " between pages. To pull out the threads would have to punch through hundreds of sheets of paper, which anyone who has tried to hole punch through a thick stack of paper knows takes a lot of force. Most of the times when screws fail in plastic it's caused by poor tolerances of screws and holes. If the hole is too big for the screw's cylindrical body, the screw can move sideways under cyclic loads, slowly chipping away the plastic holding the screw. Overtightening and sideways loads during tightening will also cause this. If a screw needs to withstand huge amount assembly/disassembly cycles (more than a few dozen) best option is a self-tapping threaded insert. These are stronger than mold-in ones (especially when used incorrectly as melt-in with) or helical coil inserts (which are not intended for this purpose at all, they are for thread repair). Mold-in inserts will not bond properly when installed using melt-in technique with soldering iron or similar. They require either ultrasonic welding device, or proper heat press if they are not injection molded in place. Hole tolerance is also critical for them to work. Edit: If you want to study more, may I recommend: www.stanleyengineeredfastening.com/-/media/web/sef/resources/docs/other/threaded_fasteners_for_plastics.ashx techcenter.lanxess.com/scp/americas/en/docguard/Joining_Guide.pdf?docId=77016 www.celofasteners.cn/img/cms/Cat%C3%A1logos%20industria/Screws%20for%20plastic%20CELO.pdf www.spirol.com/library/main_catalogs/SPIROL-Inserts-for-Plastics-us.pdf As some good starting points.
@@ilkkavierula6664 It seems like you know your stuff. Since the screws aren't actually removing material, it makes sense that cutting a new set of threads wouldn't weaken it too much. That said, it sure seems like I constantly strip threads out when I'm not careful to catch the original threads. Any thoughts on the actual problem? Am I just particularly ham-fisted? I will say that I disagree with you on the heat-setting threaded inserts. While they might not bond "properly," if the plastic is breaking before that bond fails, I'd say it's good enough. The self-tapping inserts might technically be better, but they're also an order of magnitude more expensive and I'm not sure you'd see much real-world benefit.
Two things I would love to see a follow up on: - Like most of the comments here I use primarily m3 threads. I'd like to see how comparisons change at that size - My preferred way of adding threads is to create a square hole with the same minor diameter as the screw and then threading it in. It seems like the material pushes into the corners and reduces the amount of cracking I see. I'd be great to see this experimentally confirmed
Used max layer height of 1.5 mm and changed to PETG, I am now using these parts in our industrial machines. Works great for brackets and guides. Great work like always. By the way, I have subscribed over two years ago. One of the few that I really appreciate your experiments and comments.
Seeing that you uploaded a video has been the highlight of my day. Honestly. I love your videos and hard work and I love sharing them with teachers and students I work with at a makerspace.
Yea it's really simple to do nowadays, too. For additional strength an easier insertion I can only recommend getting some square nuts (as others already suggested), as that basically removes any chance they'll start turning inside their cavities. For the same reason you also gain some leeway since the fit doesn't have to be as precise. You can also insert them in a vertical orientation without needing 'filler' parts to plug the cavities at the top a hex nut leaves. Try getting the thin version, as they don't have a more 'rounded' side and are completely flat on both sides. In Germany those are the DIN 562 variant (the thicker ones are DIN 557).
I’ve trained my brain to ignore youtubers asking for subs, but seeing people in the comments talk about subscribing and forgetting to sub, this made me realize that I’m not subscribed either. I usually don’t subscribe to 3d printing channels because I only need printing channels when I have a problem with my machine, but I decided to subscribe to this one because your content is so interesting, thank you!
The added benefit of not having to adjust the thread, model the thread etc is great but the results here are fantastic. I hadn't thought of inserts before. Brilliant video!!
Like others M 2, 2.5 and 3 are my most commonly used sizes for electronic enclosures and projects. I do use 4, 5 & 6 but not as many. Excellent as always :)
Very well done ! Thanks for sharing. As a CNC machinist for 20 yrs, I'll share some tips for too. To find the hole dia for a screw reciprocate the thread pitch then subtract that sum from your screw dia ( 1/thread pitch - screw dia = hole dia for American screws ) ( thread pitch - screw dia = hole dia for metric ) , threaded inserts are good but if a really strong thread is needed, use the Heli-coil product. Heli-coil in aluminum engine blocks is almost a standard in racing engines. When pressing in threaded inserts use a drill press. Use threaded stock in the drill chuck to press the insert into the part, heat can be apply by torch to the threaded stock. Also, the M4 is the most commonly used screw in mechanical design.
As a suggestion: Try some of the threaded repair inserts, which have a larger thread on the outside. Or some “helicoil” style to reinforce printed threads by increasing the effective diameter in the plastic.
Someone else may have already mentioned this, but you should do a 100% infill print and see if you can get the failure to occur at the actual theads and not the material around the hole. You're seeing similar strength because the failure is the same. It's the material outside of the hole where infill is weak.
I don't have a 3D printer, but I have found myself consuming plenty of media related to the technology. I am just fascinated with 3D printing, and hope to own a 3D printer one day (for little more than hobby use, probably). That said, I have found myself watching many of your videos. So many, in fact, that whenever I find myself reading large bodies of text on the subject now, I slip into reading it in your accent! As someone who is merely curious about 3D printing, but who appreciates the effort that you have put into your videos, I would like to express my gratitude. Thank you! ( subbed :) )
I'm a retired Electronics Technician. Worked in the field of military, radio and satellite Communication and consumer electronics. Although I have a hobby of Woodworking, can't get away from the tech bug. Once bitten forever changed. One day I would like to build my own CNC setup. There are so many industries that use it. Whatever my interests are at any moment, it seems that there's a CNC machine in the background. Was watching a different video of yours last night at dinner. Since I didn't want to miss out on what you were saying. I had to stop playback and explain it to my Wife before continuing. I love learning. Thank you.
one pro trick to reinforce critical areas without using very high infill percentages: strategically place a few 0,5mm holes. it's surprisingly effective for being so simple.
Awesome video. Thank you for taking the time to do this. As of now (I am too new to know when it was added) Prusa Slicer allows you to modify the part by adding a "Part modifier, Cylinder" You can then overlay that around your threads, and change the infill locally to 100%. I've done this with threads in the past, and seems to work. Since it's not adding an actual part, it doesn't do the doubling you mentioned in the video. Hope this helps!
I’ve used hexagonal shaped m3 inserts, which I’ve gently tapped with a hammer into the part, which give very good resistance to pullout (generally you have to destroy the part to get them out). Sadly, they aren’t cheap, but for a really neat and strong connection are the best I’ve found (and my uncle thinks they are really neat too)...
You could consider to test also the influence of duration of heating up the inserts. Keeping them hot without pushing further could lead to more molten environment and a better fixation.
Was thinking about using threaded inserts for a project and needed a refresher on this info. Thank you for creating this and and in depth testing. You've helped steer me in a better direction. Going to use molded threads.
as an American: metric is great for small things and precision. but you cant beat inches when it comes to rough construction like framing. it's easier/faster to say and cut 96 and a half inches rather than 2.4511 meters
Something I'll do in Fusion to add strength, which is based on your advice (I think) is to add cuts into the body, tiny cylinders, around structural parts. That way the the slicer prints extra walls where it needs support, without adding more infill.
Hi, I have used threaded inserts for a couple of projects before. I find it a very elegant solution for assembling bigger parts that need to be disassembled again. I have exclusively used inserts that have a thread on the outside so you screw them into the piece (for M4 you make a 6mm hole in which the insert perfectly screws into). I like the solution very much because it is clean and very fast (you can use a powerdrill to screw them into the hole - just takes a couple of seconds and will never come lose again) Through some tests i have made with PETG i came to the conclusion that with the correct print-settings the thread of the screw or threaded rod will break before the insert comes lose from its hole. (which kind of amazed me).
This is awesome! Seriously, this is some of the best 3DP content I've seen in a long while. I recently had to do a vehicle design project for an engineering design course and the question of how to fasten the the various components came up. Threading the PLA directly with a tap or by modelling the threads was quickly ruled as one of the design criteria was that the vehicle needed to transform and would need to be easily disassembled and reassembled multiple times without fear of the threads getting worn out or cross threading occurring. Initially everything was held together using M5 brass inserts, but after about a month of destruction testing they were eventually replaced with steel M5 nuts snugly pressed into an inset on the opposite face.
We were just having a conversation on this at work this week. We just purchased a Formlabs Form 3L. We were going to set up a number of similar variations. Thanks for saving us the time. There are Inserts for Plastic and they give the recommended hole Ø. The hole's diameter will have an effect on overall performance.
Great video! My experience using both modeled, tapped, and threaded inserts exactly matches your results. In each case where I've had a failure it has been in another location of the part, never in the threaded connectors.
Yes, doubly so if the inserts are brass. Brass is too soft to give a strong joint with the normal pitch of metric threads. That is why he stripped out the threads when he tightened too far. #316 or $304 stainless inserts are better for strength but not as good for repeated use because they tend to gall.
@Roderick storey Self tapping is also a cheap option. Even if the cover needs to be removed once a month, so long as the self tappers work for about a year, they may be used in a cheap product.
I am using M3, M2.5 & M2 for RC Airplane and UAV repairs. For my foamy Tundra bush plane, I repaired the landing gear by dremeling a hole, that after cleaning I added CA-Super Glue then the Brass insert. Worked great.
Currently, I'm using small bolts (M3 & M4) with nuts embedded into hexagon shaped recesses. Now, I'm feeling that inserts might be stronger. Could you test this?
Old video and comment, but I 100% agree, the "nut pocket" (as used significantly in the Prusa MK3S) is another great method and I think simpler overall.
As an engineer I like that you give actual figures and test in different layer directions. I generally use M3 and M4 (less so) bolts for my work and personal projects and PCB designs. When I've designed enclosures for electronics boards, I've used self-tapping screws for plastic as used in RC cars. In some cases I've seen the self-tapping screws shear the plastic inside the posts when over tightened as there are too few walls around the hole. Your local modifier mesh trick will definitely help, thank you. I have used the inserts in IP rated ABS enclosures so as to not drill holes in the box and ruin the IP rating, they had short mounting posts. A trick with the inserts in blind holes is to have a bolt screwed into the insert when melting into the part. This stops molten plastic pushing back up into the thread and blocking it. Once cooled the bolt can be unscrewed from the insert.
In plastic part design, I always teach that if the part is not intended to be assembled multiple times then screwing directly to the plastic will be the cheapest straight forward method. This is very true of automotive part design. In automotive they use thread cutting plastic screws. Rarely or never is a machine screw used in plastic for the reasons you stated. Additionally, in plastic parts, at least mass produced injection molded ones, the walls are not solid and the screw boss is it's own wall. The screw head is also important, never use a countersunk screw in plastic. That's how you get cracking from hoop stress, use a flat head or flanged screw to distribute the load. In most manufacturing scenarios the metal part receives screw threads and the plastic part tends to be a through hole that's sandwiched between the two. Great video as always!
I often use rivets to connect 3d printed parts that will never (or rarely) need to be separated. They are cheap and quick and never loosen when twisted. I've often wondered why rivets aren't used with 3d printed parts. A rivet gun is cheap, try it out!
Very unexpected that the insert did not pull free of the plastic. This solves many problems where 3D prints would normally be eliminated due to the inability to connect the parts, and alternative milled aluminum or wooden construction would have to be used. Excellent video, thank you!
I prefer to pause the print and drop a nut into a hexagon shaped hole then resume printing and capture the nut inside my print. Thought I was subbed, checked, wasn't, now subbed.
Great video! An easier way to get localized reinforcement regardless of your slicer is to make very thin (0.1mm or less) cuts in the area, forcing a double perimeter. For example: you have a 0.4mm nozzle and you want 0.8mm outside walls with 1.6mm walls around 3mm holes. Cut an extremely thin 4.6mm cylinder around the 3mm holes forcing the slicer to put two walls at the holes.
I bought 200 M3 inserts in bulk, worth every penny and have used about half of them over the last year, the only thing missing from this video is any mention of the weight gain, a few inserts and your parts can easily double in weight, I've never had a problem with this, but 'flying' parts may well suffer. also note I found a soldering iron of around 70W is best, my 15W just took too long.
Awesome video. I've been using these type of inserts in 3d prints for a while and I love them. I still use modeled threads at times, and I will sometimes use nuts where I don't have clearance to "solder" the inserts into place, but more often than not, I use the inserts. Another way to make these connections much stronger, is to put them on the opposite side, so that there is several mm of plastic between the insert and the pulling force of the screw. I mention this because there seems to be more of a tendency to torque out the parts when using PETG. At least in my experience.
Wow, I'm impressed how much all of those could handle. Although I also like the idea of making hexagonal holes in which you can precisely fit a nut. Probably more or less comparable to the inserts, but my guess would be that it may handle a bit more torque.
@@JoshuaLotion I usually put the nut in on the other side, yes. In my experience it's rare that the design doesn't allow that. And with the right tolerances I have to pull the nut into the hole using a screw, which holds tight enough afterwards that I had to destroy some printed parts to get the nut out again. It's good enough for my purposes and I can get nuts in every hardware store.
@@SaHaRaSquad Yea that does sound pretty effective and considering i have a whole box of various sized nuts. this is probably gonna be a method im gonna start using. thanks for the tip
I use threaded inserts quite often. A lot of parts I make for use at the university are fixtures, etc. that will be taken apart and put together many times so plastic threads would not hold up. I like to use expanding inserts designed to be pulled into the hole (not heat set.) I print the hole to the size needed by the insert, then ream with a drill bit to make it exact and sue a screw to pull the insert into the part. It works very well and I can even press the inserts back out to use them again (often do this while making design iterations.) I am working on a part now that holds two small wheels and needed some bearings in the plastic. I got some aluminum tubing, reamed the ID to match the bearings and then knurled the exterior, making a sleeve to hold the bearings. The corresponding hole in the 3D printed part was reamed to size and then the bearing sleeve heat set. Reaming the hole in the 3D printed part first makes the heat setting process easier, eliminates the flashing problem and make getting the sleeves square to the part much easier. I have also experimented with capturing nuts inside a part during a print. I did a few small novelty items with magnets captured inside too.
My point was that Slic3r has the functionality, in contrast to what is said in this video. But the update is indeed a huge improvement. Though the old system was good enough to make a print succeed that would have failed without it.
Great little experiment, I enjoyed watching it, just worth mentioning that oil does affect 3D prints after a while, softening PLA slightly but hardly going to bother this test. And I would probably grab yourself a nice genuine Torque Wrench that will give you more accurate results for a test like this where you are showing Torque results, but a good indication, well done.
Great video as usual, with a very good subject. I would be interested to see that with PETG as it is my main filament for mechanical parts. I usually use, non molded for M2.5 and M3
I’ve been looking for some inserts this morning for my prints but didn’t know that I needed knurled ones (I didn’t get any because I was only finding wood screwed ones) I have purchased a set on you link thank you so much, exactly what I need.
In my prints I add a small hexagonal pocket at the end of the hole to insert a nut. My biggest concern is compression of the plastic when the screw is tightened. I address this problem by simply printing 6 small holes that go through the plastic. These holes actually make that area stronger, particularly for compression, because of the added material inside around the screw hole. I have attached 1/4" screws (to hold ball bearings) with this method and have never had a failure (but this was at a lower load than in your tests). I use ABS. It would be interesting if you could measure this approach in future tests.
I've been using these lately and i am impressed how well they stick. I made a temperature controller for cheap soldering iron that i use to heat them, it was real nice to use inserts on that box too, it came out looking quite nice with hidden threaded inserts instead of bolts.. I did post about this quite recently in one facebook 3D printer group.. my results were the same, the brass inserts were superior and even partially bonded inserts held really well but that is a lot about what temps you melt them. Too cold and they can be literally pulled out by hand but once you get the temp just right, they will stick to brass permanently. The key is to use using high temps and use as little force as possible, they should sink in almost under their own weight. But the all that time you are also heating everything around them. Put the part to a freezer and then do the inserts with quite high temps and fast worked by far the best. So.. i'm making a press for this using two 8mm rails and linear bearings, the whole procedure really needs a straight push. Soldering iron and eyeballing it is way, way too inaccurate specially for longer bolts. edit: here is the temp control box, it has just basic eBay dimmer circuit inside. imgur.com/a/6z0KATA edit2: funny, i talked about inserting new walls using curas "support blocker" too in the same group to enforce holes for inserts and for drilling.. :) it almost looks like you have been following the same groups.. That is just great :)
Thank you! I have also tried it different ways and my method of choice is to embed the nut into the printed part. It could be fully embedded or inserted sideways, or from the back. M3 is probably the most common size, followed by M4.
I watched your last 5 videos without even noticing I wasn't subscribed because yt kept recommending me more, definitely deserved a sub tho, really nicely made test
The annoying background music ruins the video???? why did you even bother adding music that 99% of people will not enjoy and about 20% will just stop watching?
I don't model threads for one-time use connections. Directly screwing screws or bolts into appropriately sized holes have been working fine without any splitting. For threads that get lots of screwing in and out, I just use inserts like you and they work just fine - both PLA and PETG.
Great video. There are tapered inserts specifically for heat or ultrasonic insertion. I use inserts primarily for high use or when a design would benefit from a shallow thread.
The problem with M3 is that the head of the bolt and the nut are quite small and can't take any load. Using a washer and a brass insert will make them way better. I use M5 and M6 otherwise, it is not about the strength the bolt&nut can take but the area that the bold head and nut will cover to get just a bit more torque and to prevent creep.
You are right. People watching without subscribing. I was one of them till one minute ago. You should put in this test the version of embedded nut or the hexagonal hole for the nut. I think this version will be more resistant because you will have more material around the hexagonal hole due to more complicated geometry. Also, I didn't test but I think the gradual infill will help in this case even if is done only on vertical. As you can see, a massive damage is present at the top surface also. So a gradual infill and increasing layers for the surfaces (wall thickness) will help.
At work we use tons and tons of M2,M2.5, and M3 heat set inserts from McMaster Carr. They are great for parts you want to be able to remove easily, but still tighten securely and maybe use some loctite if necessary. The disadvantage is that if you don’t get the insertion perfect, you end up with scrapped prints.
We use metal inserts in our 3d printed grow lights, BUT we use push in expansion type rather than melting them in which is a bit tedious and also prone to being crooked. The best type for resisting pull out are the reverse headed type where they push in from the BACK side and have a rim which means they cant be pulled through. these will give you by far the strongest threads if you are screwing all the way through a piece. We use them and have never had a problem, even when the courier manage to seriously damage the unit (throwing one over a 3 meter/9 foot wall for example) the inserts were unaffected.)
yes, PETG, ABS, ASA and perhaps Nylon would be great. Threads are usually to be used in straonger (constructional) material so it would be great to know how to do threads for mentioned materials :)
Considering many tripod camera bases are made from plastic, you'd probably be fine.
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I use M4 and M3. Around 90% of my printing is in ABS. I don't model or cut threads or embed nuts in the design. I found out that on a correctly sized hole, using the bolt directly produces a thread that is less likely to split or break the plastic than using a nut. I tried tapping, but I like the tighter feel of the "self tapped" threads more. Nice to know that their strength is good compared to the amount of effort that you have to put. Also, in my experience, it's very unlikely to split the part, if something needs a little more torque I make sure to design it so it prints horizontally or I make the hole (and bolt) longer. I will also experiment with the threaded inserts, thank you for showing that. Always nice to have other options! Thanks for the informative video, hope you do the same with ABS and PET.
Nylon sucks for such uses. It is not stiff enough. Nylon is tough so it is good for applications where giving a bit but not failing is the best option.
@@stalawina Inserts will do better. They spread the same force over more area. I suggest stainless ones for high loads. Brass avoids galling but is too soft for the standard metric tread sizes. Most folks don't want to have to use special screws. #304 stainless is almost hard enough to get the full rating out of standard screws.
Hey Stefan, Great tests, I was surprised how well the threaded inserts performed. I have used them before, but not for any significant stress situations. Now I know they are far more capable than I thought.
I would say that that 75% unsubbed might be skewed As there is probably a group like me; people who also watch your stuff on a different device that they’re not logged into Such as me on my computer
For working molded product at Emarena Corporation I use threaded self tapping wood inserts for multi piece 3D prints. I over size the holes, a 3mm minimum thickness and plastic epoxy glue the product in to fill. Soldering in the fittings or tapping result in early failure rates due to high torsion. Use of SS machine socket bolts with black (rough) carbon steel fittings provide grip for a few hundred uses prior to expected failure. Polished ss to ss typically require over tightening.
I've been happily subbed for a more than a year to Stephan's channel and I've gone back and viewed many of the first videos that I missed! He does interesting stuff, digs deep, and makes it understandable. On top of that, he seems like a very nice young man. All it takes is a mouse click to subscribe to this great resource and it helps him expand to even more interesting subjects. Please click that button....
For threads I've been using modifiers in Cura to ensure that the area of the thread is %100 infill. I then drill a hole 1/16'th smaller than the recommended for a standard metalworking tap on my drill press (because the material is soft) and then tap as I would a piece of aluminum. No lubrication required. This has worked well on PETG and ABS.
In case you revisit this theme: May I suggest also testing the self-cutting threaded inserts from Boellhoff Type: "56000000079/01" ? Strength-wise they should perform like a thread directly cut into the plastic but with a relatively huge diameter. They are easy to use and you don't need to mess with a soldering iron to get the insert into the plastic part. These might be even stronger than the brass inserts (that got stripped), since these self cutting threaded inserts are made of steel. There is an expensive tool to insert them, but you can also just use a screw with some hex-nuts on them as an insertion tool. Anyway, very cool video, keep up the good work!
As always, a well thought out set of tests. I have been using inserts in my prints for a couple of years now, but get lazy sometimes and just print the threads. Seeing the difference, you have cured me of this. Thank you!! 👍
Being a mechanical engineering researcher myself, I absolutely love how accurate your experiments are. Not only do you try changing one variable at once, but you tell us where errors may come from. However, I'd really be even more impressed if you could formulate your experiments mathimatically so that, given any set of variables, you could find the maximum allowable stress.
It was a major pity that the torque wrench was out of a Kinder Egg!
The ratio of time needed to end up with an 11 minute video must be at least 100:1. Just to do the engineering and get the raw footage. Even more after editing.
I'm certain there are very few Creators who have so much hard work behind each minute of video.
The machine deflects before the part yields. Not very accurate
@@sheet-son Well I don't expect him to buy a super expensive tensile testing machine. So given his tools and budget, it is pretty accurate.
@@dmail00 Actually, a beam type torque wrench can be very accurate for this kind of thing. Typically better and more repeatable then a click type or electronic.
The primary benefit of the inserts is that you can screw and unscrew many times without the threads wearing out.
Matthew Humphrey exactly, plastic threads are sensitive to torque as he said and wear out quickly even with the right torque tightening
@@rotorblade9508 Not if you use a proper screw with threads designed for plastic. I don't get why people use machine bolts in 3d-printed objects as they are designed for metal threads. There exists such a thing as screw designed for plastic. You can get these for free from any broken appliance with plastic enclosure. Easier to use, better grip, and no need for threads, just a suitably sized hole.
@@ilkkavierula6664 The screws designed for plastic work great in applications where you screw it together and then never take it apart. Since these screws are designed to cut threads, if you remove them and put them back in, it's very easy to accidentally cut a new set of threads instead of screwing into the existing threads. That is a recipe for stripped threads.
On commercial products, you often see thread-cutting screws holding most things together, but then a threaded insert and machine screw on things like battery doors that get repeated use.
If you are able, you should have both thread-cutting and machine screws on hand and use the best screw for any given job. If your screw variety is limited by space, budget, or other factors however, I would consider machine screws to be more versatile.
@@jcon6734 Most of the time they settle on the existing threads. Especially if you start screwing with light force without forcing it (as you are supposed to do with any screw). Even if the screw cuts multiple threads it doesn't significantly weaken the holding power of the screw. This is due to the mechanics of how to screw works. The factor determining the holding power of screw in material is the shear strength of the material and screw threads. The variable determining the shear strength is the shear surface area and shear strength of the material. The amount of material removed by the thin thread of a plastic screw is so little it hardly has an effect on the shear surface area, thus the effect on pullout strength is very small.
It can be a bit counterintuitive, but you can try it yourself by screwing a piece of wood to a phone catalog or old book. It will hold there very firmly even though there are hudreds of "threads " between pages. To pull out the threads would have to punch through hundreds of sheets of paper, which anyone who has tried to hole punch through a thick stack of paper knows takes a lot of force.
Most of the times when screws fail in plastic it's caused by poor tolerances of screws and holes. If the hole is too big for the screw's cylindrical body, the screw can move sideways under cyclic loads, slowly chipping away the plastic holding the screw. Overtightening and sideways loads during tightening will also cause this.
If a screw needs to withstand huge amount assembly/disassembly cycles (more than a few dozen) best option is a self-tapping threaded insert. These are stronger than mold-in ones (especially when used incorrectly as melt-in with) or helical coil inserts (which are not intended for this purpose at all, they are for thread repair). Mold-in inserts will not bond properly when installed using melt-in technique with soldering iron or similar. They require either ultrasonic welding device, or proper heat press if they are not injection molded in place. Hole tolerance is also critical for them to work.
Edit: If you want to study more, may I recommend:
www.stanleyengineeredfastening.com/-/media/web/sef/resources/docs/other/threaded_fasteners_for_plastics.ashx
techcenter.lanxess.com/scp/americas/en/docguard/Joining_Guide.pdf?docId=77016
www.celofasteners.cn/img/cms/Cat%C3%A1logos%20industria/Screws%20for%20plastic%20CELO.pdf
www.spirol.com/library/main_catalogs/SPIROL-Inserts-for-Plastics-us.pdf
As some good starting points.
@@ilkkavierula6664 It seems like you know your stuff. Since the screws aren't actually removing material, it makes sense that cutting a new set of threads wouldn't weaken it too much. That said, it sure seems like I constantly strip threads out when I'm not careful to catch the original threads. Any thoughts on the actual problem? Am I just particularly ham-fisted?
I will say that I disagree with you on the heat-setting threaded inserts. While they might not bond "properly," if the plastic is breaking before that bond fails, I'd say it's good enough. The self-tapping inserts might technically be better, but they're also an order of magnitude more expensive and I'm not sure you'd see much real-world benefit.
Two things I would love to see a follow up on:
- Like most of the comments here I use primarily m3 threads. I'd like to see how comparisons change at that size
- My preferred way of adding threads is to create a square hole with the same minor diameter as the screw and then threading it in. It seems like the material pushes into the corners and reduces the amount of cracking I see. I'd be great to see this experimentally confirmed
square hole ?! thx I'm gonna try that in my next design
Once again, doing great things for the community. Thanks. great video!
Used max layer height of 1.5 mm and changed to PETG, I am now using these parts in our industrial machines. Works great for brackets and guides. Great work like always. By the way, I have subscribed over two years ago. One of the few that I really appreciate your experiments and comments.
Hands down the BEST 3DP content creator! Asking the real questions
Seeing that you uploaded a video has been the highlight of my day. Honestly. I love your videos and hard work and I love sharing them with teachers and students I work with at a makerspace.
i use m3 most often. and i often use pause and insert normal nuts inside the part
cool, I'll have to try that
yeah square nuts are better i just had a hard time getting them and have 1000+ of normal hexagon nuts 😁
@@tetraliteproducts542 you can buy square nuts off aliexpress for 1/10th the price
Yea it's really simple to do nowadays, too. For additional strength an easier insertion I can only recommend getting some square nuts (as others already suggested), as that basically removes any chance they'll start turning inside their cavities. For the same reason you also gain some leeway since the fit doesn't have to be as precise. You can also insert them in a vertical orientation without needing 'filler' parts to plug the cavities at the top a hex nut leaves.
Try getting the thin version, as they don't have a more 'rounded' side and are completely flat on both sides. In Germany those are the DIN 562 variant (the thicker ones are DIN 557).
I use M3 for everything 3d-printing related.
I do too
Me too :) And i'd be interested if results with PETG are the same, cause that is the material i use 90% of the time ^^
Me too.
M3 is definitely the most used for 3d prints
Same. M2 for the tiny stuff and M3 Torx head for pretty much everything else. Usually don't print parts that require something as large as a M5.
ive started using brass inserts and now will be using them exclusively
This saves us a lot of tests. Thebk you!
I’ve trained my brain to ignore youtubers asking for subs, but seeing people in the comments talk about subscribing and forgetting to sub, this made me realize that I’m not subscribed either. I usually don’t subscribe to 3d printing channels because I only need printing channels when I have a problem with my machine, but I decided to subscribe to this one because your content is so interesting, thank you!
How on earth can 75% not be subbed!? This is the most interesting 3D printing channel on TH-cam.
The added benefit of not having to adjust the thread, model the thread etc is great but the results here are fantastic. I hadn't thought of inserts before.
Brilliant video!!
Like others M 2, 2.5 and 3 are my most commonly used sizes for electronic enclosures and projects. I do use 4, 5 & 6 but not as many. Excellent as always :)
Very well done ! Thanks for sharing. As a CNC machinist for 20 yrs, I'll share some tips for too. To find the hole dia for a screw reciprocate the thread pitch then subtract that sum from your screw dia ( 1/thread pitch - screw dia = hole dia for American screws ) ( thread pitch - screw dia = hole dia for metric ) , threaded inserts are good but if a really strong thread is needed, use the Heli-coil product. Heli-coil in aluminum engine blocks is almost a standard in racing engines. When pressing in threaded inserts use a drill press. Use threaded stock in the drill chuck to press the insert into the part, heat can be apply by torch to the threaded stock. Also, the M4 is the most commonly used screw in mechanical design.
As a suggestion: Try some of the threaded repair inserts, which have a larger thread on the outside. Or some “helicoil” style to reinforce printed threads by increasing the effective diameter in the plastic.
I have been using threaded inserts for about a year now and absolutely love them! It’s also fun to assemble.
Someone else may have already mentioned this, but you should do a 100% infill print and see if you can get the failure to occur at the actual theads and not the material around the hole. You're seeing similar strength because the failure is the same. It's the material outside of the hole where infill is weak.
I don't have a 3D printer, but I have found myself consuming plenty of media related to the technology. I am just fascinated with 3D printing, and hope to own a 3D printer one day (for little more than hobby use, probably).
That said, I have found myself watching many of your videos. So many, in fact, that whenever I find myself reading large bodies of text on the subject now, I slip into reading it in your accent!
As someone who is merely curious about 3D printing, but who appreciates the effort that you have put into your videos, I would like to express my gratitude.
Thank you! ( subbed :) )
If you ever revisit this, try doing oversized threads with a helicoil insert to bring them to spec in addition to the other tests
Yes, helicoil!
Yes!
I'm a retired Electronics Technician. Worked in the field of military, radio and satellite Communication and consumer electronics. Although I have a hobby of Woodworking, can't get away from the tech bug. Once bitten forever changed.
One day I would like to build my own CNC setup. There are so many industries that use it. Whatever my interests are at any moment, it seems that there's a CNC machine in the background.
Was watching a different video of yours last night at dinner. Since I didn't want to miss out on what you were saying. I had to stop playback and explain it to my Wife before continuing.
I love learning. Thank you.
"Because still, 75% of you watching right now are not following the channel."
Oh dam, you right. **click**
I just noticed...
Damn, now i feel bad. Somehow, even without being subscribed, youtube always answered my questions with the perfect CNC kitchen video.
I don't need to subscribe. youtube keeps recommending this channel anyway even though I don't have a 3D printer. 😁
I love how in-depth this man goes into stuff likes this, and the way he explains it is just solid and simple!
one pro trick to reinforce critical areas without using very high infill percentages: strategically place a few 0,5mm holes. it's surprisingly effective for being so simple.
I love how you quantify what others assume. Beautiful information
The prusa edition of slic3r allows for modifier shapes to be created and imported.
Awesome video. Thank you for taking the time to do this. As of now (I am too new to know when it was added) Prusa Slicer allows you to modify the part by adding a "Part modifier, Cylinder" You can then overlay that around your threads, and change the infill locally to 100%. I've done this with threads in the past, and seems to work. Since it's not adding an actual part, it doesn't do the doubling you mentioned in the video. Hope this helps!
I’ve used hexagonal shaped m3 inserts, which I’ve gently tapped with a hammer into the part, which give very good resistance to pullout (generally you have to destroy the part to get them out). Sadly, they aren’t cheap, but for a really neat and strong connection are the best I’ve found (and my uncle thinks they are really neat too)...
We are manufactured brass insert components and mouldings components
I have used nuts for bigger bolts, and sometimes even screwed directly into the hole (with
You could consider to test also the influence of duration of heating up the inserts. Keeping them hot without pushing further could lead to more molten environment and a better fixation.
Was thinking about using threaded inserts for a project and needed a refresher on this info. Thank you for creating this and and in depth testing. You've helped steer me in a better direction. Going to use molded threads.
Finally a video using the metric system. Pleasantly surprised i didnt hear you say "23,6/465th hole".
I have to apologize for my fellow Americans. They are stuck in their ways, I wish we used metric.
only idiots would say it like that :P
I absolutely love the metric system.
as an American: metric is great for small things and precision. but you cant beat inches when it comes to rough construction like framing. it's easier/faster to say and cut 96 and a half inches rather than 2.4511 meters
This is my first vid with you. SUBBED in 4 minutes of the video!!!! My tiny brain understands your way of teaching quite well. TY!
Something I'll do in Fusion to add strength, which is based on your advice (I think) is to add cuts into the body, tiny cylinders, around structural parts. That way the the slicer prints extra walls where it needs support, without adding more infill.
Man, that tensile strength tester you made is the best thing to happen to 3d printing in years
U R the best 3d printing Channel!
Hi, I have used threaded inserts for a couple of projects before. I find it a very elegant solution for assembling bigger parts that need to be disassembled again.
I have exclusively used inserts that have a thread on the outside so you screw them into the piece (for M4 you make a 6mm hole in which the insert perfectly screws into). I like the solution very much because it is clean and very fast (you can use a powerdrill to screw them into the hole - just takes a couple of seconds and will never come lose again)
Through some tests i have made with PETG i came to the conclusion that with the correct print-settings the thread of the screw or threaded rod will break before the insert comes lose from its hole. (which kind of amazed me).
neither do i own a 3d printer nor have any experience with engineering. still find your videos extremely interesting. please go on 8)
This is awesome! Seriously, this is some of the best 3DP content I've seen in a long while.
I recently had to do a vehicle design project for an engineering design course and the question of how to fasten the the various components came up. Threading the PLA directly with a tap or by modelling the threads was quickly ruled as one of the design criteria was that the vehicle needed to transform and would need to be easily disassembled and reassembled multiple times without fear of the threads getting worn out or cross threading occurring. Initially everything was held together using M5 brass inserts, but after about a month of destruction testing they were eventually replaced with steel M5 nuts snugly pressed into an inset on the opposite face.
I like how it was used in the industry for many years and now we use it in our kitchen
We were just having a conversation on this at work this week. We just purchased a Formlabs Form 3L. We were going to set up a number of similar variations. Thanks for saving us the time.
There are Inserts for Plastic and they give the recommended hole Ø. The hole's diameter will have an effect on overall performance.
I mostly use M3 and M4 with M5 only on bigger items. Great video BTW.
Great video! My experience using both modeled, tapped, and threaded inserts exactly matches your results. In each case where I've had a failure it has been in another location of the part, never in the threaded connectors.
I am Using threaded inseets mostly on parts which are disassembled regularly because they don't strip. Not for strength...
Yes, doubly so if the inserts are brass. Brass is too soft to give a strong joint with the normal pitch of metric threads. That is why he stripped out the threads when he tightened too far.
#316 or $304 stainless inserts are better for strength but not as good for repeated use because they tend to gall.
@Roderick storey
Self tapping is also a cheap option. Even if the cover needs to be removed once a month, so long as the self tappers work for about a year, they may be used in a cheap product.
I am using M3, M2.5 & M2 for RC Airplane and UAV repairs. For my foamy Tundra bush plane, I repaired the landing gear by dremeling a hole, that after cleaning I added CA-Super Glue then the Brass insert. Worked great.
Currently, I'm using small bolts (M3 & M4) with nuts embedded into hexagon shaped recesses.
Now, I'm feeling that inserts might be stronger. Could you test this?
Old video and comment, but I 100% agree, the "nut pocket" (as used significantly in the Prusa MK3S) is another great method and I think simpler overall.
As an engineer I like that you give actual figures and test in different layer directions. I generally use M3 and M4 (less so) bolts for my work and personal projects and PCB designs. When I've designed enclosures for electronics boards, I've used self-tapping screws for plastic as used in RC cars. In some cases I've seen the self-tapping screws shear the plastic inside the posts when over tightened as there are too few walls around the hole. Your local modifier mesh trick will definitely help, thank you.
I have used the inserts in IP rated ABS enclosures so as to not drill holes in the box and ruin the IP rating, they had short mounting posts. A trick with the inserts in blind holes is to have a bolt screwed into the insert when melting into the part. This stops molten plastic pushing back up into the thread and blocking it. Once cooled the bolt can be unscrewed from the insert.
Servus,
Um ein M5 Gewinde zu schneiden, ist eine 4,2mm Kernbohrung der Standard, das fehlende Material beeinflusst deinen Test
Great test. But as Kartaurus is pointing out you should have drilled 4.2 mm. I have used 4.5 mm for M5, but only for selfthreading screws.
In plastic part design, I always teach that if the part is not intended to be assembled multiple times then screwing directly to the plastic will be the cheapest straight forward method. This is very true of automotive part design. In automotive they use thread cutting plastic screws. Rarely or never is a machine screw used in plastic for the reasons you stated. Additionally, in plastic parts, at least mass produced injection molded ones, the walls are not solid and the screw boss is it's own wall. The screw head is also important, never use a countersunk screw in plastic. That's how you get cracking from hoop stress, use a flat head or flanged screw to distribute the load. In most manufacturing scenarios the metal part receives screw threads and the plastic part tends to be a through hole that's sandwiched between the two. Great video as always!
I often use rivets to connect 3d printed parts that will never (or rarely) need to be separated. They are cheap and quick and never loosen when twisted. I've often wondered why rivets aren't used with 3d printed parts. A rivet gun is cheap, try it out!
Very unexpected that the insert did not pull free of the plastic. This solves many problems where 3D prints would normally be eliminated due to the inability to connect the parts, and alternative milled aluminum or wooden construction would have to be used. Excellent video, thank you!
I prefer to pause the print and drop a nut into a hexagon shaped hole then resume printing and capture the nut inside my print. Thought I was subbed, checked, wasn't, now subbed.
That is quite genius. Thanks for that tip.
How do you avoid getting hotend hitting the insert?
Quality science, clear understanding of engineering principles, clear understanding of good 3D modeling. I subscribed after one view.
Keep it up!
I think you should do the same test with other sizes, it seems m3 is popular, and also test the nut insert method.
Great video! An easier way to get localized reinforcement regardless of your slicer is to make very thin (0.1mm or less) cuts in the area, forcing a double perimeter. For example: you have a 0.4mm nozzle and you want 0.8mm outside walls with 1.6mm walls around 3mm holes. Cut an extremely thin 4.6mm cylinder around the 3mm holes forcing the slicer to put two walls at the holes.
I bought 200 M3 inserts in bulk, worth every penny and have used about half of them over the last year, the only thing missing from this video is any mention of the weight gain, a few inserts and your parts can easily double in weight, I've never had a problem with this, but 'flying' parts may well suffer.
also note I found a soldering iron of around 70W is best, my 15W just took too long.
Awesome video. I've been using these type of inserts in 3d prints for a while and I love them. I still use modeled threads at times, and I will sometimes use nuts where I don't have clearance to "solder" the inserts into place, but more often than not, I use the inserts. Another way to make these connections much stronger, is to put them on the opposite side, so that there is several mm of plastic between the insert and the pulling force of the screw. I mention this because there seems to be more of a tendency to torque out the parts when using PETG. At least in my experience.
Wow, I'm impressed how much all of those could handle. Although I also like the idea of making hexagonal holes in which you can precisely fit a nut. Probably more or less comparable to the inserts, but my guess would be that it may handle a bit more torque.
unless the nut was inserted from the underside with a small lip at the top surface, wont the nut just pull out the moment you try to tighten sth down?
@@JoshuaLotion I usually put the nut in on the other side, yes. In my experience it's rare that the design doesn't allow that. And with the right tolerances I have to pull the nut into the hole using a screw, which holds tight enough afterwards that I had to destroy some printed parts to get the nut out again.
It's good enough for my purposes and I can get nuts in every hardware store.
@@SaHaRaSquad Yea that does sound pretty effective and considering i have a whole box of various sized nuts. this is probably gonna be a method im gonna start using. thanks for the tip
I use threaded inserts quite often. A lot of parts I make for use at the university are fixtures, etc. that will be taken apart and put together many times so plastic threads would not hold up. I like to use expanding inserts designed to be pulled into the hole (not heat set.) I print the hole to the size needed by the insert, then ream with a drill bit to make it exact and sue a screw to pull the insert into the part. It works very well and I can even press the inserts back out to use them again (often do this while making design iterations.)
I am working on a part now that holds two small wheels and needed some bearings in the plastic. I got some aluminum tubing, reamed the ID to match the bearings and then knurled the exterior, making a sleeve to hold the bearings. The corresponding hole in the 3D printed part was reamed to size and then the bearing sleeve heat set. Reaming the hole in the 3D printed part first makes the heat setting process easier, eliminates the flashing problem and make getting the sleeves square to the part much easier.
I have also experimented with capturing nuts inside a part during a print. I did a few small novelty items with magnets captured inside too.
Slic3r does allow you to add those modifiers in the slicer, it's just really unintuitive and clunky.
Get the beta. It's a lot less bad.
It's not bad in the regular, non-prusa, version
My point was that Slic3r has the functionality, in contrast to what is said in this video.
But the update is indeed a huge improvement.
Though the old system was good enough to make a print succeed that would have failed without it.
Great little experiment, I enjoyed watching it, just worth mentioning that oil does affect 3D prints after a while, softening PLA slightly but hardly going to bother this test. And I would probably grab yourself a nice genuine Torque Wrench that will give you more accurate results for a test like this where you are showing Torque results, but a good indication, well done.
Stefan has a Canyon. Good choice, great video :-)
Perfektes Timing :). Hatte heute überlegt die Teile auch mal zu besorgen. Danke!
Muss in der "Luft" liegen... Amazon hat heute ebenfalls mir ein Set von Inserts angeboten
Great video as usual, with a very good subject. I would be interested to see that with PETG as it is my main filament for mechanical parts. I usually use, non molded for M2.5 and M3
We are manufactured brass insert components and mouldings components
1:58
I’ve been looking for some inserts this morning for my prints but didn’t know that I needed knurled ones (I didn’t get any because I was only finding wood screwed ones) I have purchased a set on you link thank you so much, exactly what I need.
Thanks for the testing. I've wondered about thread strength in parts. Do you think ABS would be stronger or weaker than PLA in this regard?
In my prints I add a small hexagonal pocket at the end of the hole to insert a nut. My biggest concern is compression of the plastic when the screw is tightened. I address this problem by simply printing 6 small holes that go through the plastic. These holes actually make that area stronger, particularly for compression, because of the added material inside around the screw hole. I have attached 1/4" screws (to hold ball bearings) with this method and have never had a failure (but this was at a lower load than in your tests). I use ABS. It would be interesting if you could measure this approach in future tests.
m3 and m2 are common in the FPV community which has a tendency to also use 3D printers. great video, very thorough, subbed
I've been using these lately and i am impressed how well they stick. I made a temperature controller for cheap soldering iron that i use to heat them, it was real nice to use inserts on that box too, it came out looking quite nice with hidden threaded inserts instead of bolts.. I did post about this quite recently in one facebook 3D printer group.. my results were the same, the brass inserts were superior and even partially bonded inserts held really well but that is a lot about what temps you melt them.
Too cold and they can be literally pulled out by hand but once you get the temp just right, they will stick to brass permanently. The key is to use using high temps and use as little force as possible, they should sink in almost under their own weight. But the all that time you are also heating everything around them. Put the part to a freezer and then do the inserts with quite high temps and fast worked by far the best. So.. i'm making a press for this using two 8mm rails and linear bearings, the whole procedure really needs a straight push. Soldering iron and eyeballing it is way, way too inaccurate specially for longer bolts.
edit: here is the temp control box, it has just basic eBay dimmer circuit inside. imgur.com/a/6z0KATA
edit2: funny, i talked about inserting new walls using curas "support blocker" too in the same group to enforce holes for inserts and for drilling.. :) it almost looks like you have been following the same groups.. That is just great :)
"Slick 3 R" LMAO
Sanladerer is influential.
Thank you! I have also tried it different ways and my method of choice is to embed the nut into the printed part. It could be fully embedded or inserted sideways, or from the back. M3 is probably the most common size, followed by M4.
Thanks TH-cam Algorithm. Finally a good recommendation. Subbed !!
I watched your last 5 videos without even noticing I wasn't subscribed because yt kept recommending me more, definitely deserved a sub tho, really nicely made test
Want to get your 3D prints to the next level? Check out our Heat Set Inserts and Tools at cnckitchen.store (Free shipping worldwide starting at €100).
CNC Kitchen Ich würde dir KEENSERTS Gewindeeinsätzen empfehlen. Die halten in Kunststoff Bombenfest. 😬😑
I would’ve subscribed if it wasn’t for the way you say Slic3r. :)
The annoying background music ruins the video???? why did you even bother adding music that 99% of people will not enjoy and about 20% will just stop watching?
Feel free to share the video (link or embedded TH-cam player) but please don't re-upload or self host it.
3d printed parts is made of plastic just melt the thing together to make connections
I don't model threads for one-time use connections. Directly screwing screws or bolts into appropriately sized holes have been working fine without any splitting. For threads that get lots of screwing in and out, I just use inserts like you and they work just fine - both PLA and PETG.
Excellent topic!! Thank you.
Great video. There are tapered inserts specifically for heat or ultrasonic insertion. I use inserts primarily for high use or when a design would benefit from a shallow thread.
M5 is huge and overkill I would say.
Normally I go to either M3 or M4
The problem with M3 is that the head of the bolt and the nut are quite small and can't take any load. Using a washer and a brass insert will make them way better. I use M5 and M6 otherwise, it is not about the strength the bolt&nut can take but the area that the bold head and nut will cover to get just a bit more torque and to prevent creep.
@@squidcaps4308 I think, the brass inserts would really help m3, since you make the influence of the head size less
You are right. People watching without subscribing. I was one of them till one minute ago.
You should put in this test the version of embedded nut or the hexagonal hole for the nut. I think this version will be more resistant because you will have more material around the hexagonal hole due to more complicated geometry. Also, I didn't test but I think the gradual infill will help in this case even if is done only on vertical. As you can see, a massive damage is present at the top surface also. So a gradual infill and increasing layers for the surfaces (wall thickness) will help.
im wondering how 76% of y'all arent subbed yet
It's easy.
At work we use tons and tons of M2,M2.5, and M3 heat set inserts from McMaster Carr. They are great for parts you want to be able to remove easily, but still tighten securely and maybe use some loctite if necessary. The disadvantage is that if you don’t get the insertion perfect, you end up with scrapped prints.
The inserts you linked to, weren’t the same as in your video. I can’t find inserts like yours anywhere. Do you have a link maybe?
We use metal inserts in our 3d printed grow lights, BUT we use push in expansion type rather than melting them in which is a bit tedious and also prone to being crooked. The best type for resisting pull out are the reverse headed type where they push in from the BACK side and have a rim which means they cant be pulled through. these will give you by far the strongest threads if you are screwing all the way through a piece. We use them and have never had a problem, even when the courier manage to seriously damage the unit (throwing one over a 3 meter/9 foot wall for example) the inserts were unaffected.)
Wow, Nice test 👍😀
PetG would bee Nice to check as well😀👍
yes, PETG, ABS, ASA and perhaps Nylon would be great. Threads are usually to be used in straonger (constructional) material so it would be great to know how to do threads for mentioned materials :)
Very cool test. Good to know the knurled nuts are the way to go. I can't believe I didn't consider pressing them into a part with a soldering iron!
1/4 inch and 3/8 please standard camera threads on Tripods
Considering many tripod camera bases are made from plastic, you'd probably be fine.
I use M4 and M3. Around 90% of my printing is in ABS.
I don't model or cut threads or embed nuts in the design. I found out that on a correctly sized hole, using the bolt directly produces a thread that is less likely to split or break the plastic than using a nut.
I tried tapping, but I like the tighter feel of the "self tapped" threads more.
Nice to know that their strength is good compared to the amount of effort that you have to put.
Also, in my experience, it's very unlikely to split the part, if something needs a little more torque I make sure to design it so it prints horizontally or I make the hole (and bolt) longer.
I will also experiment with the threaded inserts, thank you for showing that. Always nice to have other options!
Thanks for the informative video, hope you do the same with ABS and PET.
That's the way to go Stephan. Now in nylon?
Nylon sucks for such uses. It is not stiff enough. Nylon is tough so it is good for applications where giving a bit but not failing is the best option.
@@kensmith5694 you have a point.
@@stalawina Do you use threads or inserts?
That is the topic
@@stalawina
Inserts will do better. They spread the same force over more area. I suggest stainless ones for high loads. Brass avoids galling but is too soft for the standard metric tread sizes. Most folks don't want to have to use special screws. #304 stainless is almost hard enough to get the full rating out of standard screws.
Hey Stefan, Great tests, I was surprised how well the threaded inserts performed. I have used them before, but not for any significant stress situations. Now I know they are far more capable than I thought.
I would say that that 75% unsubbed might be skewed
As there is probably a group like me; people who also watch your stuff on a different device that they’re not logged into
Such as me on my computer
Your videos are teaching me how to 3D print (professionally).
..okey..is ja schon gut..hab dann auch mal aboniert! ;)
For working molded product at Emarena Corporation I use threaded self tapping wood inserts for multi piece 3D prints. I over size the holes, a 3mm minimum thickness and plastic epoxy glue the product in to fill. Soldering in the fittings or tapping result in early failure rates due to high torsion. Use of SS machine socket bolts with black (rough) carbon steel fittings provide grip for a few hundred uses prior to expected failure. Polished ss to ss typically require over tightening.
3:59 bruh in like little parts of the video it’s an American talking
Edit: it might be the editor
i have not yet tried to integrate screws into prints because of hoop stress and the expansion when metals rust. I think this is a game changer
I've been happily subbed for a more than a year to Stephan's channel and I've gone back and viewed many of the first videos that I missed! He does interesting stuff, digs deep, and makes it understandable. On top of that, he seems like a very nice young man. All it takes is a mouse click to subscribe to this great resource and it helps him expand to even more interesting subjects. Please click that button....
Thanks!
For threads I've been using modifiers in Cura to ensure that the area of the thread is %100 infill. I then drill a hole 1/16'th smaller than the recommended for a standard metalworking tap on my drill press (because the material is soft) and then tap as I would a piece of aluminum. No lubrication required. This has worked well on PETG and ABS.
In case you revisit this theme: May I suggest also testing the self-cutting threaded inserts from Boellhoff Type: "56000000079/01" ? Strength-wise they should perform like a thread directly cut into the plastic but with a relatively huge diameter. They are easy to use and you don't need to mess with a soldering iron to get the insert into the plastic part. These might be even stronger than the brass inserts (that got stripped), since these self cutting threaded inserts are made of steel. There is an expensive tool to insert them, but you can also just use a screw with some hex-nuts on them as an insertion tool. Anyway, very cool video, keep up the good work!
As always, a well thought out set of tests. I have been using inserts in my prints for a couple of years now, but get lazy sometimes and just print the threads. Seeing the difference, you have cured me of this. Thank you!! 👍