3D Printed Pneumatic Actuator... It Actually Works!

this is a 3D printed pneumatic cylinder that I designed and built from scratch and it works surprisingly well this all started because the other day I was cutting up some wood and I realized there has to be a better way of doing this one thing led to another and before I knew it I designed the pneumatic cylinder there it is and then strapped it to the sawt this makes cutting wood way easier and I can just sit back and relax honestly I can't believe nothing like this has ever been invented but anyway let's rewind how I actually built this pneumatic so to get started building this thing I selected a pipe to use as the cylinder walls you could potentially 3D print this but PVC pipe is so easy to get there's really no point in doing that this pipe is rated up to 320 PSI and it comes in clear which will make really good visuals for this video but to turn this pipe into an actuator we need to cap both ends the end caps combined with the Piston inside create two different pressure Chambers by controlling the pressure in these Chambers we can make the Piston extend or retract and to make these parts I'm just going to use Standard fdm Printing since 3D prints are made up of a bunch of layers and they're not solid plastic I was initially concerned about them leaking especially at higher pressures so I changed the print settings to have six wall perimeters and increase the print temperature by a couple degrees this should ensure we have the best layer adhesion possible these ended up turning out really well and they feel really solid eventually these parts are going to have air fittings installed into them so I went ahead and tapped some threads inside the actuator this is the actual piston which separates the two pressure Chambers this is also just 3D printed and attaches to an 8 mm Steel Rod using an O-ring and a bolt this is the same type of Steel Rod that gets used on 3D printers a lot so they're super cheap and easy to find to actually seal the Piston to the cylinder wall two O-rings get added to the outside the rod can then also get inserted through the front cylinder cap now to keep air from actually leaking around the cylinder rod there's two more O-rings in the front cap these can be a little trickier to install but with a pair of tweezers or a small screwdriver it's not too bad at this point everything's actually ready to go together these things are surprisingly simple there's really just three parts on this first iteration I'm going to attach the end caps with epoxy I made sure to sand both sides to get the best Bond possible and hopefully this will make everything airtight putting these parts together with the epoxy was actually really satisfying but I realized two major flaws number one this thing is no longer serviceable I can't take it apart to replace components that break or even just upgrade stuff so clearly that has to change in future iterations and secondly this stuff takes over 24 hours to dry and I'm way too impatient for that now although this first iteration does have flaws I do want to still test it just to prove that this is even possible so after waiting forever for the glue to dry I could add some oil to help lubricate the Piston seals and then attach some air fittings and this is where I ran into my first problem as I was tightening down the air fitting I heard a cracking sound and saw the print had actually split along the layer Line This was definitely because I tighten the fitting way too much but the worst part was since I epoxied the end caps on I couldn't really do anything about it so to try to fix it I dabbed some super glue on top of the crack and then sprayed it with some hardener to actually control which side of the Piston gets pressurized I'm going to use this it's a solenoid valve that has two different output ports normally the air is output out of this port but when I attach the two leads of the selenoid to a battery the valve switches and the air comes out of the other Port this will make the Piston extend and retract attaching all the hoses to the Piston we're actually ready to give this thing a test all right we're going to start with a nice easy 30 PSI let's hook it up now this cylinder did definitely leak a little bit but most of it was probably for my sketchy super glue repair job all right three two one oh my God but honestly it still worked really well so I did the obvious thing and just tried to crush stuff with it after just a few actuations I took the pressure all the way up to 80 psi one and everything seemed fine but then the mounting Point actually broke this was not what I expected to break first but it should be an easy fix so I think it's time for some improvements so I went back to the drawing board and CAD reprinted the endcaps retapped the holes this time I printed the Piston with resin for extra durability after a quick wash and cure O-rings get installed as well as some new O-rings on the endcaps these are needed because the endcaps are no longer held on with epoxy instead some 4mm threaded rods hold everything together now as I showed in the last version this entire thing can be made on a normal fdm printer but if you don't have a resin printer and you want to try resin Parts the sponsor of this video PCB way might be really helpful they offer a ton of services including 3D printing CNC manufacturing and even injection molding to get this piston part made on one of their SLA machines it only cost a couple dollars and they have tons of materials you can choose from as well I've used a lot of their services in the past for both PCB manufacturing and CNC Machining so check them out using the link in the description below now back to the video after all the assembly is complete we now have version two testing version two showed that it works just as well as version one and that has even less leaking I was able to crank the pressure all the way up to 110 PSI without any problems doing some quick math at this pressure it's putting out about 75 lbs of force it can even break through some Thin [Applause] plywood however while doing this I had my first real failure every time the actuator extends the momentum of the piston and the rod all gets transferred into this front end cap and this happens really quickly this means it's basically like hitting that front end cap with a hammer eventually this was just too much for the 3D print and the whole thing broke apart luckily there's an easy fix for this all I need to do is add some Springs this will make the transfer of momentum a lot slower and therefore less force will be applied so after reprinting everything one last time and assembling the part with the new Springs the final test I want to do with this actuator is cycle it on and off over and over again to see if it wears out or fails now the obvious way to do this is with a microcontroller like an Arduino however I decided to make my life difficult and I built this the actuator is attached to the sliding bar which has two arms on it the two arms flip a toggle switch back and forth which either extends or retracts the actuator this means it's essentially controlling itself and it's just going to keep going until something breaks or runs out of air I also rigged up a counter which gets hit every time the Piston extends this will track the number of cycles that the actuator does so after hooking everything up we're ready to go let's see what this thing can really [Music] do honestly this setup worked way better than I was ever expecting the counter did a great job keeping track of all the cycles and the Springs definitely appear to be working too I ran this test at about 50 psi and you can see the pressure and the momentum really compressed this spring as it gets to the end of its stroke so since everything was working I just let this setup go and over the course of the next half hour this thing did over 10,000 Cycles hitting over 10,000 Cycles with this was really impressive to me I thought for sure something was going to wear out anyway it looks like this design is working great now if you're interested in building something like this luckily I designed this all using on shape which is the free to use CAD platform and what's great about on shape is it's all online based so I can just put a link in the description below and you guys can use the files and create your own versions or just print the exact same thing and use it so check out the link below in the description if you're interested and I'll also throw a list down there of some of the hardware you need to do this now next steps for this I want to see how much pressure this thing can actually hold but to do this we're going to switch from being pneumatic to hydraulic so my plan is to use this hydraulic pump to see how much force we can generate until something breaks and trust me something will break so if you want to see that make sure to subscribe and I'll see you guys in the next [Music] video

Channel: Michael Rechtin

Views: 125,678

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Id: NwrLrIPK99A

Length: 8min 16sec (496 seconds)

Published: Fri Dec 15 2023