Crafting a Powerful 3D Printed Bow: Strength Testing Different Materials!

[@anthonyp4209]

Bowstrings are generally strung under tension rather than loose.

[@3DJake_Official]

Actually very good point! Next time!

[@B0A2]

I’d love to see a part two with the advice from the comments being used.

[@3DJake_Official]

It'll happen :)

[@henkheijmen]

Nice idea but I was kind off dissapointed with the method. I did some testing with small springs for a little toy pistle and what I found: - PCTG can stretch much furter without breaking, good for a bow - Nylon CF is Very rigid and can't bend as far without breaking I have also made bows from wood, and generally speaking, the specs of pctg are much ore suitable for the limbs. True it is relatively flexible, but that can be offset by widening the limbs. So I was dumbstruck when you swapped over to nylon limbs on a pctg riser, it should have been the other way around! Pctg is much more flexible and has a higher impact resistance then petg, but other than that, it isn't much stronger. Next thing to consider, the length of the limb is the leverage that is put on itself, so in order to equally stress each part of the limbs, they need to get thinner towards the tip. If this isn't the case, they are stressed alot at the base where it connects to the riser, and the entire remainder of the limb is basicly useless. You want the entire limb to bend equallyt as much to get the maximum flex from the material. Then, as someone mentioned, a bowstring is strung under tension, without it your arrows will flipflop all over the place as seen in the tests. The arrow flipflopping is partially to blame on the distance to the target and the stifness of the arrow. An arrow typically bends a bit when shot, which it has to do. If an arrow is to stiff or to floppy for the strenght of the bow, your arrows will be way of target. Short arrows like this will make them relatively more rigid, so that is something to keep in mind. And as mentioned, when shot, the arrow bends a bit around the bow, then it will bend the other way after leaving the bow, this motion will repeat itself slowly diminishing over the first few meters of the arrow. This means if you shoot at very close targets, your arrows will still be in this bending motion, throwing off your aim quite a bit. This effect is only amplified when shooting with arrows that are much to stiff. Lastly, you trying make a recurve bow, which is much harder to make then a normal bow, maybe start with the normal one Explanation: The re-curved tips function as an extra lever that comes available when the bow is fully pulled. This makes it require relatively little effort to hold the bow while aiming. however this again also means the tip of the limb flexes less, and this entire benefit is only available if the curved edges are paralell to each other in the pulled position of the bow, which requers more testing and calculations. If this is desireable I would print the recurved tips in a different material and attach them similar like how the limbs are attached to the riser. So: 1. use a different bow design (no recurve) 2. Make limbs that are tapered towards the tip 3. Make riser from a stiff material and the limbs from a flexible material 4. If the pulling strength is too weak, make the limbs wider not thicker 5. Rethink the arrows: use thinner arrows if they need to be this short, but ideally design the bow to be able to curve furter, so you can keep the long arrows.

[@3DJake_Official]

This is fantastic advice, thank you!! We did try PCTG a little further than what was in the video but it yielded easily. I really want to try again though and with your tips I think it can be improved a lot.

[@zevakikel]

Hi Jake!, an amateur archer and 3D printing enthusiast here. In redesigning the riser, it is important to consider the following: - Include a "shelf" where the arrow will rest. - If you are right-handed, then that "shelf" should be on the left side of the riser. - The grip (where your hand rests) should be almost in the center of the riser, so the top of the riser should be longer than the bottom, and the arrow rest must be in the center of the string. - It is essential that the rope be "pretensioned" in the bow, and that it not be allowed to become slack. This will greatly enhance the power of the bow. By being prestressed, the string will be supported by the "undulations" of the limbs.

[@3DJake_Official]

Really helpful advice! Thank you!

[@engineericly]

I used PETG and some metal profiles for the bow in my recent Shorts video, It was pretty durable, but I wish you upload this video before I shoot that video ;) thanks for pretty useful insights!

[@ggervacio1973]

20kg! very impressive draw weight. Still tons of room for design improvements, but with advances in filament materials, a 100% printed tournament bow is probably not very far away. Did the the limbs develop a set, or permanently deformed? Or did it retain it's original shape? Very excited with this. Thanks for sharing.

[@3DJake_Official]

Oh for sure, we're gonna address the flaws in another video to improve it. People already gave awesome advice in the comments. The nylon CF limbs are totally undeformed, that's what I was worried about but I think next time we'll try pure nylon to give the limb tips extra flex, CF was a little bit too rigid.

[@kirisilvermane]

Make yourself a rig where the bow is held on the wall and you pull downwards test it: look at a tillering rig on KZbin. Means you can pull without risk of it hitting you in the face. Plus bows are strung to a brace height; when strung the bow limbs are already under tension by maybe 10-15%. What you’ve made there is far closer to a crossbow prod than a true bow. So maybe continue and make a crossbow? More than happy to help and advise if you need it: I make bows ;)

[@ggervacio1973]

Try to use a "tillering tree" when testing so when the bow breaks, the pieces will not fly toward you, and you will be able to pull the string far away. Hope you will do more bow prints.

[@3DJake_Official]

Thanks! Definitely doing one more to fix the flaws with this one :)

[@deadlymedley3306]

Awesome power, thanks for making and sharing 3d printed bow stuff. I was able to get a substantial increase in both strength and power for my 3d printed limbs by using ca glue to bond a 0.8mm thick strip (printed flat) to the outside faces of my limbs or in your case the front faces. I have a reverse draw set up so protoyping limbs is much safer because they won't come flying back at my face should they break but this is only helpful info if you're making a crossbow since they only work on crossbows

[@75keg75]

I made a 19” riser and plotted half scale as a test - I stood on it to see what it would handle and it didn’t move. I’m around 125kg. I was going to get some 40lb ilf limbs and hardware and build up a full scale but have been smashed at work. I printed with 10-15 perimeter and Infill was about 50% rectilinear. I also did solid layers every 12 layers to add some strength. Plotted in prusament petg. I also plotted some limbs but they are untested. For weight.

[@willdoch]

Wait! I see a FLSUN S1 in the background. Please make a review of this printer. I would love to see if the claims hold true.

[@3DJake_Official]

It'll happen!

[@Edramon53]

Interesting project. If you have a local archery shop, maybe you could spend some time with your hands on a real bow? I feel like there's some design aspects that have been long-solved in archery not applied here. If that's because it's just a quick design for testing the concept fair enough but I'm sure riser and limb shapes could be improved. Length and stiffness of arrows are also usually chosen based on the stats of the bow. Personally I'd be quite interested in testing the components individually - e.g. get a real recurve riser and try 3d printed limbs with it. Get some regular recurve limbs and try them with a printed riser, etc.

[@3DJake_Official]

Individual testing and comparison with manufactured bows is a great idea. It was intended as a quick design but its also a first iteration, I do intend to improve it in future, actually some other people gave great advice down below so there is no end to improvements.

[@nerys71]

Something to keep in mind especially with lower grade materials carbon fiber never makes them stronger ever under any conditions In fact this is true of all materials with the exception of that special process that actually laid a continuous carbon fiber filament there is no such thing as a filament that is stronger with carbon fiber in it This is simple physiology or whatever you call it you are compromising the structural integrity of a homogeneous plastic by putting voids in it but it's carbon fiber I don't care what it is You're putting voids in the plastic that makes it weaker no matter what Carbon fiber does exactly two things it gives you a more matte finish which for artistic princess absolutely stunning I love carbon fiber PLA for artistic prints and it trades the strength you give up by putting voice in the plastic for stiffness Now there are times where this could be advantageous such as nylon and that's only because for many of our applications the nylon is significantly stronger than mission specifications so it's stronger than what you need to do what you want to do then you can afford to give up some of that strength in exchange for stiffness as long as that strength does not drop below mission requirements But all plastics no matter what it is get weaker when you add a fill because the fill creates voids that's where the feel exists in those voids and those voids always make the plastic weaker

[@3DJake_Official]

We decided to use carbon fibre to preserve stiffness like with modern fibreglass bows, that's what I meant by "strength", actually pure nylon would probably have been a better choice and I think we might try this for version 2, that and a new limb design with PCTG. I was worried that the limbs would be too flexible and would easily bend back without building up much force but using carbon fibre might have made it a little too rigid. Definitely going to redesign a few things for the next version.

[@Hex3d-v5y]

You could make the limbs and the razer bigger by printing it one at the time placed diagonal on the bed

[@eddieyip9546]

The grip is always the weakest point even for a real recurve/ compound riser. It needs a partial reinforcement using 60-80% infill

[@spedi6721]

Maybe it could help using a bigger nozzle. So you got less lines and layers that can delaminate.

[@3DJake_Official]

I remember reading that bigger layers and widths don't necessarily mean higher strength as the gap between layers is proportional as you increase the layer height, bigger layers means bigger gaps between them. CNC kitchen recently did a video exploring layer deposition with offset layers that look like brick work, that could help.

[@spedi6721]

@@3DJake_Official oh, need to check this out. Thx

[@Martial-Mat]

Placing a high tension, sprung object next to my eye, then tensioning it. What could go wrong?

[@nerys71]

Some suggestions I am not an archery person and I don't know how to design a bow but some things I've noticed as a self-proclaimed DIY engineer First the riser No more cutouts get rid of the place where the arrow goes get rid of the place where your hand goes Make it a cylinder so to speak something stupid strong that does the necessary job When it comes to making it ergonomic do that with additions so print the ergonomic part so that it gets glued on to the riser that's a simple shape this way the simple shape super strong riser is handling all the force load and the parts you attach to it don't have to handle nearly so much force there's simply there to make the riser more ergonomic to your hand kind of like the way the handlebars are on your bike or just super strong metal tubes and then you add handlebar grips friction tape the angled risers that you see on performance bikes stuff like that then gets added to that riser do something similar with the riser for the bow I would also lengthen the limbs a tiny bit and put a little precurve into them so that you can put a taunt but not tight bow string on it you don't want to put it under too much tension because the plastic might creep over time This is also something while expensive I would test to destruction you want to put an arrow in it on a test rig and test it until it fails you want to see most importantly how it fails so you know which parts of your body you need to protect :-) probably mostly your face and your forearms the amount of energy in those limbs if they were to suddenly give way would be pretty dramatic to your skin and your face

[@htw007]

I would use TPU 95A with 50-60% infill.

[@cybernetix86]

I think it would work better with some tension/preload on the bow. Did you break the TV?? 😂🤣

[@3DJake_Official]

No TVs were harmed in the making of this video. And yeah we're definitely stringing with tension next time :)

[@weissefabrik]

8:20 geplante obsoleszenz :DDD um 90 oder 45 grad gedreht, wäre das nicht passiert

[@TS_Mind_Swept]

And make sure not to design weak points into the Riser this time SuperVinlin

[@jarchdm]

You are shooting a left handed bow with your right hand. The arrow rest is supposed to be on the left side of the bow so that when you shoot Mediterranean draw the arrow gets pulled in towards the bow not off the shelf like this

[@3DJake_Official]

Ah thank you!!

[@jarchdm]

@@3DJake_Official If you are really going to make bows i highly suggest watching some bow making videos, Helm bowman for instance make some very interesting bows, he has one that's the shortest he has made but its still 3 times the length of what you are working with. the limbs you are making are more suited to cross bows when looking at the length. the strength of the limbs you made is impressive but i assume making longer ones are restricted by the bed size of your printer. very ambitious 3d printing bow limbs but in my view not the most practical if you actually want to shoot a real bow at full draw.

[@jarchdm]

@@3DJake_Official also kramer ammons has a really good " will it bow" series where he makes bows out of all sorts of materials. He is a professional bowyer who loves experimenting to get the best bow and he's getting close !

[@3DJake_Official]

@@jarchdm Wow! Cool! Thank you! I definitely want to improve on this so this will be really helpful :)

[@3DJake_Official]

It has been several hours since I replied. I can't stop watching kramer ammons videos

[@reyalPRON]

i get much stronger petg prints than you it seems, i extrude at 265c 10% fan. 140mms walls and 220 infill. i cant break the benchys i make even with hammers, need a vice or a cutting tool ;) also there are interesting blends of the stuff too. but pctg seems to perform better in every factor except price and variety so far. But it will come with fillers like petg has today hopefully sooner rather than later. personally i like asa as my prototype material today. who uses abs when there is asa i say.

[@3DJake_Official]

I share your opinion with regard to ASA however regarding the PETG, I think you're referring to impact strength, I need to bend this part without it snapping or yielding. Some people in the comments gave good advice regarding PCTG and I want to try that again, still a bit nervous about it but I want to make it work.

[@TheWuzyy]

Try Polymaker Polymax Tough PLA for that bow.

[@blackhand9581]

Sliding Legolini.

[@RebellisSpiritus]

STL?

[@3DJake_Official]

This is way too dangerous to release the stl 😬

[@chevdor]

That's just a very bad idea and people will end up getting injured. There are just sooo many cool parts one can make for archery and only a few you really should not. Those are risers, limbs and Nocks. Bad bad idea....

[@LORRE21]

test bench is not that great!

[@The_Privateer]

As an archer and bow hunter for 20 years, and a 3D printing enthusiast for 10, I can't even begin to address all the fail and everything wrong in this video. It's clear that even the most rudimentary research was not done. The dictionary has a picture of this guy for the definition of 'ignorant'.

[@micheles7782]

Firsttt