If I may suggest, you should send this video with your resume to True North Arms. They already manufacture a few solutions for both Gen 1 and Gen 2 of the WK (eg., shell deflector, adjustable gas valve, reinforced bushing, pins, charging handle, etc). They take product suggestions on their website too. They might be able to bring something to market, and you could get your foot in the door in the industry.
I agree completely. Or alternatively, if they want the piston to go out the front of the gas block, just make the hand guard and receiver a bit taller to accommodate a larger piston. I’m sure people would rather their hand guards are a bit thick / incompatible with AR-15 hand guards than having a catastrophic failure after 150 rounds
@@cabbage6015 if they made the hand guard and receiver a bit taller to make more room for the piston, then it would also be possible to fix the issue with quick detach optics not being able to clip on the pic rail. 2 problems solved for the price on one. 😉
@@cabbage6015 thoughts on the LMT external piston system? Seems as reliable as the SVT/416 system from what I've seen and goes out the front of the monolithic upper receiver.
Adding the video of the 180 firing and seeing the piston flexing alongside the barrel whip I believe your analysis is spot on. The free play in the old 180 design certainly reduces stress in the flex of the system too allowing the main rod to remain straighter on the axial forces. I've been around firearms my whole life and at one time also owned the sks and the type 97, I looked them over very well and your observations are things I never thought of. Even if you don't go further into the firearm industry your eye for detail is a great asset on the internet. Keep doing this!
Because the projectile is long out of the muzzle by the time the piston starts moving and the barrel starts flexing. Then the barrel returns to its original state and repeat the cycle
This is well laid out and a good analysis of what is happening to these firearms. You are on a good path. I hope you come up with some other analysis on other issues, I'd like to see what you come up with.
Nice video. It seems like an elementary flaw to substantially and abruptly reduce the diameter of that piston rod or shaft especially at mid length. That will certainly create a stress riser potentially creating microfractures that will eventually progress to failure. Unfortunately all semiautomatic rifles may be outlawed before these guys get their problems fixed.
Fired over 1500 rounds out of me WS-MCR and haven't had any issues so far. I've taken it down to the individual parts and put it back together several time and everything seems good for now.
That is exactly what I said but probably 5000 rounds. Then my piston blew apart. Lol. Hoping it hasn't caused further issues I was having feeding problems afterwards. Waiting on a new piston to find out
I think that your analysis is accurate. It seems as if they designed the system without considering how the piston would flex. The fact that this issue is still a problem with the Gen 2 version of the 180c, Kodiak needs to do some serious soul searching and decide if they really want to be in the firearms business.
How could a company designing a rifle not shoot two thousand rounds through it before mass production. Biggest scammers wk and m+m m+m can't even go ten rounds
Nice video. I think the best option would simply be to covert it to a DI system. Spectre ballistics supposedly has a DI bcg in the works. I’m hoping to pick one up when that gets released
Awesome video! I have very limited knowledge but this definitely added to it! I have a WK-180c gen 2 that has had this issue recently. I almost wonder if someone has gone as far as to machine an aftermarket piston that could replace the stock one in the rifle. Or if that's even possible. I'd be willing to test new options, I definitely don't want to be replacing it every few hundred rounds.
It's baffling to me that _everyone_ seems totally unwilling to actually do what needs doing to fix the issue: replicate the multi-piece piston that the 180 had to begin with. Instead, WK and WS keep fiddling with the existing, flawed design, and Crusader just decided to make it gigantic.
THE KING IS BACK! Love your coverage of lesser known modern firearms, any other firearms you have your eye on? Love your coverage of CCP firearms, bravo!
i believe Kodiak implemented a better design of the piston system in the WK181 gen2. Kodiak claims it was needed for 7.62x39 ammo, and they are saying its not needed for WK180, but I think the WK181 piston could be used on the WK180. Please have a look at the WK181 gas system.
15:07 I have a technical questing roaming my had for a while. A gas piston is an accelerated mass am I right? And according to Newton all accelerated masses will create recoil impulses? Will an accelerated gas piston do create a recoil impulse that acts on the gasblock pushing it forward?
I would say yes, but it’s not a separate mechanism to what I said in the video. When the piston is pushed back, it does mean that the gas block is pushed forward, but the thing that pushes both these objects is the gas pressure within the gas block
@@cabbage6015 Thank you very much. I also have another question about a longer text, that often get deleted by RUclips, can I contact you on Instagram to set it to you?
Having a piston that is the same diameter across the entire piston is important to have consistent stress buckling, but it's cheaper and easier to make one that is thicker.
Regarding the cracked part you encountered at work, what material was it made of? Steel shouldn't be that notch sensitive, but if it's aluminum or titanium it would make a lot of sense that machining mark notches expand over time and crack the part. Just my layman's understanding of crack propagation/notch sensitivity.
With your first piston rod fix, I think it would benefit from a guided sleeve on top/built into the barrel nut. This would minimize maximum deflection under recoil. Think of it like on an sks. I finished watching your vid and see you discussed it. Lol.
Ok, I got my T65 out of the safe. It's a 20" M16 length gun, with an M16 length gas system in AR18 style. Its piston is in fact thinner in diameter on the spring portion than the portion between the spring and the cup. Not by much, but it is. I'll send you pics on instagram. Also, from the wider section that the spring rests on to the thinner section the spring surrounds, the angle is literally 90 degrees. This rifle is about 50 years old but the piston isn't bent. HOWEVER, the difference in thickness between the two sections of piston is much less drastic than in these Canadian AR18s. A further note is that the literal piston at the front, the cup that goes in between it and the pusher rod, and the pusher rod itself, when all connected together, CAN BE BENT. This means it's possible some of the bending is released effectively by these portions as joints. Notably, these Canadian 180s are ONE PIECE and have no equivalent joints. Yep lmao, already see this is part of proposal 1. It is unlikely proposal 2 is patented. It's existed for like thirty years (G36, HK416) and people have successfully legally made clones of it (Titan Defense 416 uppers for instance)
Yea I noticed that the front section of the piston in the T65 photo is a bit thicker too, but I think it's still demonstrates the point so I didn't pay too much attention to it. I'm kinda surprised that there is no fillet at all though. Also if you can, would you mind taking the diameters of the T65 pistons?
@@cabbage6015 I'm not sure if I have a way to precisely measure diameter but I'll check if my dad does. It will at the least get vague measurements. The other changes in diameter on the T65 all have fillets.
All the models here are . 223 or 5.56, I got a ws mcr in 7.62 x39, and it came with a pistón cup like in your last suggestion, ws mcr does not have a manual they are too cheap to provide one in order to find out torques or any more info
Cool video! your stuff always tickles my noggin! I have trouble understanding how proposal 1 would reduce the bending torque on the con rod tho… If you had two sections of a pushrod with a guide at the contact point that guide would constrain the radial freedom of movement and prevent one rod just slipping past the other one. The guide would transmit radial forces to the pushrods and the only bending torques applied to the rods would be those caused by buckling, which would indeed be much smaller due to the shorter aspect ratio of the rods. Your proposal does not feature such a guide though. In that case a system with two pushrods (in the mech. engineering sense of the word) would be under-constrained. The joint between the two sections of the con rods would have to restrain the relative radial movement of the sections by transmitting a bending torque between the connecting rods, which would mean that the stresses from that torque would be just as large as in the original design.
The only workaround without a guide I can come up with, is to loosen the fit between the two sections of pushrods to the point that it would allow enough relative radial movement as to not transmit any torque. But that would mean that the system is now under-constrained and that the gas block and the hole in the receiver would have to transmit the torque to restore a fully restrained system. That would mean increased wear however - Especially between the hardened steel rod and the aluminium receiver - and might lead to jamming of the gas system. Am I overlooking something?
I’m definitely least confident in proposal 1. My train of thought is that, bending of the piston rod is produced by traverse deflection of the barrel, the amount of which will be the same regardless of the piston design. So if there is some clearance at the joint between 2 rod sections, some of the deflection will be taken up by that clearance, and the parts themselves will deform less, resulting in lower bending moment. The clearance should not be too much that the radial motion of the rod ends is completely unconstrained. The “cup” feature of the rear rod should contact the OD of the front rod once a certain amount of deflection is achieved, and ideally this amount should be less than the deflection of the barrel. I had some concern with that cup feature. Just due to how small everything is, the walls of that cup will be very thin. So I intentionally used a “normal” drill bit with an angled point to drill the cup. My hope is that the conical surface at the bottom of the cup, when pushed against the conical end of the front rod, will exert a force that helps push the two rod sections back into alignment, thus reducing the stress on the cup wall (but honestly idk how much it will help). You’re right that the clearance between the two rods might increase the wear on the receiver. If you look at 9:37, there is a brass bushing between the receiver and piston rod, which is shown in my CAD as well (I believe on some guns this bushing is nylon). So the receiver would be protected at least, but the bushing might need more frequent replacement. There is also an option to use a steel bushing, which I believe is what the HK 416 uses. That is also partly why in Proposal 2, I made the spacer recessed inside the receiver, so that it acts as a bushing and becomes a consumable part. But yeah, Proposal 1 is definitely the most sketchy, and the cup feature of the rear rod can potentially become a new breaking point, not to mention the increased wear. My intention with Proposal 1 is that the implementation is as simple as possible, and that’s the biggest selling point. The low performance is the biggest trade off.
The trick, and it´s simple, is to use a hollow shaft, a tube as it were. This way you increase buckling resistance without an increase in weight. The ID would give you the opportunity to house a spring and locate other elements into it like a cylinder where the gas could expand it. Get it?
I think your analysis is right but he problem can be solve with a simpler solution. Add a stop so that the piston doesn't over compress the spring. Increase the rounding at the diameter change. Reduce the diameter of the front portion to equalize stiffness. Choose a material with higher tensile strength. If necessary, add a guide to reduce buckle. The other solution would go to a SCAR type architecture with the spring and piston inside the gasblock and a connecting rode attached to the bolt carrier with a guide mid length of the barrel.
I don't understand why they don't use a rifle-length gas system. It's not a problem on the AR-18 or the very long SVT40 and SVD, even the beloved SKS, so why the carbine-length system?
I've been holding off on a 180 due to part breakages too. If a retrofit will address this issue I'd buy a cheap gen1 or 2. No way I'm spending over 2000$ on the new Templar though. It also looks way too heavy
The Templar with a fixed AR buffer tube and milspec trigger is just 1700 tho. But yea I handled one at Taccom last weekend. Can confirm front heavy. But honestly I don't think it would be much worse than a Type 81
Interesting stuff. I used to have to do the same for pistons on hydraulic actuator systems... Too many stripped or cracked threaded sections from where customers used them improperly or overstressed them in new applications... Cowboy lawnmower drivers taking them off high curbs and screwing up the steering rams😅
Oh please do if you have the chance. The G36 is a proper military rifle adopted by multiple countries, with a robust gas system. The gas system problem mentioned in my video only applies to the rifles I mentioned and other with similar piston designs. The G36 is not one of them
The brn180s likly has a thicker piston due to the increased gas pressure where the gas port is located kn the barrel vrs lower gas pressure further down the barrel.
What's weird to me is that I can tell externally if a rifle was made in Canada for civilian market due to the new laws. Random little things like screws and a weirdly high number of flat surfaces. I was even able to sniff it out before researching one that was available in the US, too.
Wait? I didn't know that they're available in the US. I think the Templar at 14:26 will be tho. Also yea if you find a WK180 or WS MCR in the US don't touch em. You guys have way better options lol. Even in the modernized AR-180 niche the Brownells ones will blow these out of the water. And yea honestly the high number of flat surfaces and screws just screams low-cost machining to me lol.
@@cabbage6015 Sooch00 just did a review of the Templar. They are actually setting up shop in Michigan for the US market. And marketing to the US by sending out for review by the content creators on RUclips. Overall I do agree with your remarks. I think the big part is the choices in metals. They are tough and wear resistant but lack the ability to flex. I had a NEA15. Barrel was very accurate until it wasn’t. It cracked after a few hundred rounds under muzzle device. NEA/BCL replaced it no problem with a new barrel. My gunsmith informed me that it was a common problem being too brittle. I hade to eventually rebuild the whole rifle from the receiver up. I do think a simple redesign to the original 180 piston assemble that can be a drop in upgrade could solve the problems.
Hey Cabbage! What do you think of turning down the heavy front half of the piston to the same dia as the rear spring section. Obviously leaving the piston head at full 1/4 like the sks and leaving a shoulder for the spring to push against. Thoughts?
Hmm the rear spring section is really small, I don't know the exact number but I'd guess it's about 3/16" or smaller. I'm afraid that if we turn the whole piston length to that diameter it would buckle in a heart beat. I would say that as we reduce the front section, the # of cycle to buckling failure would decrease, but the # of cycle to fracturing at the stress concentration would increase. Maybe there is a diameter where these two #'s are the same, I'd guess it's somewhere between 1/4" and 3/16"
@@cabbage6015 really appreciate the advice. I ordered a second piston and will have the machine shop chop ahead of the fillet on one and at fillet on the other . I will have them drill out a cup on the rear peice and turn down a male end to mate with the cup for forward peice. Will report after a few hundred rounds. Could be a few months
@@matthewmartin9313 Oh damn, I'm really anxious now, I hope my proposal doesn't fail miserably lol. If possible, please make sure that the surface is polished afterward such that there is no machining marks. And thank you for the effort!
Hey Cabbage, what do you think of the Templar by crusader arms? Would the thicker piston further impede gradual deflection? I'm not sure if the small dia' portion of the piston is the same as the WK180. Seems like the SAI R18 Mk2 might have the best piston design on the Canadian market.
I think the Templar is better than the WK180, but the thicker portion would again transfer most of the deflection to the thinner portion. It would be better if they reduce the diameter of the thicker portion. Yeah I also agree that the R18 piston is the best. The upcoming SRV2 from Black Creek Labs is the same design as well. However I would add that there is some issue with the R18. My local range rent out 3 R18s, and all of them has developed some short stroking issues after some time, with 2 failing to cycle every single round, effectively turning them into bolt action rifles
@@cabbage6015 Thank you for the input. Ive been considering purchasing one of those two rifles and I'm almost inclined to buy a templar and reduce some portion of the templar piston on a lathe equal to the smallest diameter, keeping the features to retain the spring. They seem to have good reviews from what little is out there.
In your opinion do you think American made civilian firearms have relatively better quality than Canadian?Because I’ve heard a lot of different Canadian civilian guns having issues more so than American made firearms.
Oh absolutely, the US probably has the biggest civilian firearms market in the world. They also don’t have to worry about their products being banned on a whim the day after release, so they’re less likely to skim on R&D. I have no doubts that US-designed civilian firearms are leagues above Canadian ones.
Why are you not the chief engineer for these firearms? Anybody that would dedicate this much time with detailed information and computer generated analysis should be. Their engineers shit the bed big time. I feel R&D must have been minimal at best to rush these out the door after the ban. Anyways great job, thanks for posting why so many are failing at such low round count.
Many small gun companies don't have "engineers" per say - rather tinkerers and machinists who may or may not have an understanding of physics, stress, fatigue, etc.
I really hope the Crusader Arms Templar would be better. It's only 200 bucks more than the WK and WS. Their piston design is still the same sub-optimal geometry but hopefully it's so oversized that it wouldn't be an issue. Black Creek Labs is also coming out with a non restricted SRV2 and that looks much more promising, I just hope that the price will be sub 2k...
T91's gas piston is a tooless front removable self contained unit,which I consider to be a better design than even the HK416,and I'm really biased towards the HK416(just see my profile pic lol
Why not use SKS piston system? There’s a reason why AR platform moved away from 180 system. Too complicated and many problems with pistons. Why not direct impingement if nothing else? When certain weapon systems are developed you usually have government involved with almost limitless amount of cash. This usually gives engineers enough time and support they need to develop a reliable system. This also means they have a lot of testing done to ensure dependability of the system they are developing. In this case a firearm system that was abandoned decades ago due to its reliability issues was RECYCLED because it had to comply with new gun control measures. Gun companies wanted to make sure they could continue making profit and by using already developed systems to reduce the cost of developing a new system, they simply ignored the fact that this "recycled" system has many problems. Honestly I find this very selfish just because it seems like they capitalized on an unjust gun ban and used the opportunity to recycle a system that was abandoned long time ago BECAUSE of design problems and reliability issues. What worries me even more is that no one, NO ONE thought it was weird that we went back to 180. No one would even look at this system if a gun ban was not introduced so if you, gun manufacturers in Canada honesty wanna help Canadian firearm owners and give us options until this unjust OIC gun ban is resolved and if you wanna use already developed reliable systems please, use the ones that actually work.
wk180c worst gun ever. TNA should have started over with this cheap ass gun. I had to modify the whole gun so it would be reliable . the type 97 5.56 is wayyyyyyy better if you like bullpups.
![A comprehensive look at the QBZ 191 small arms family [OUTDATED - CHECK PINNED COMMENT]](/img/1.gif)
As a firearms engineer, this is spot on. Keep up the great videos.
If I may suggest, you should send this video with your resume to True North Arms. They already manufacture a few solutions for both Gen 1 and Gen 2 of the WK (eg., shell deflector, adjustable gas valve, reinforced bushing, pins, charging handle, etc). They take product suggestions on their website too. They might be able to bring something to market, and you could get your foot in the door in the industry.
Thanks for the suggestion! I’ll look into that
I'd like to see a return to the original style of the AR180B/SVT40 piston/rod setup. I don't care if I have to remove the forend to clean it.
I agree completely. Or alternatively, if they want the piston to go out the front of the gas block, just make the hand guard and receiver a bit taller to accommodate a larger piston. I’m sure people would rather their hand guards are a bit thick / incompatible with AR-15 hand guards than having a catastrophic failure after 150 rounds
@@cabbage6015 if they made the hand guard and receiver a bit taller to make more room for the piston, then it would also be possible to fix the issue with quick detach optics not being able to clip on the pic rail. 2 problems solved for the price on one. 😉
@@cabbage6015 thoughts on the LMT external piston system? Seems as reliable as the SVT/416 system from what I've seen and goes out the front of the monolithic upper receiver.
Adding the video of the 180 firing and seeing the piston flexing alongside the barrel whip I believe your analysis is spot on. The free play in the old 180 design certainly reduces stress in the flex of the system too allowing the main rod to remain straighter on the axial forces.
I've been around firearms my whole life and at one time also owned the sks and the type 97, I looked them over very well and your observations are things I never thought of. Even if you don't go further into the firearm industry your eye for detail is a great asset on the internet.
Keep doing this!
That barrel whipping clip 5 minutes in is crazy. Makes you wonder how a gun is ever able to accurately fire a projectile at a target.
Because the projectile is long out of the muzzle by the time the piston starts moving and the barrel starts flexing. Then the barrel returns to its original state and repeat the cycle
This is FANTASTIC! Well done sir. Your video ia extremely under appreciated
This is well laid out and a good analysis of what is happening to these firearms. You are on a good path. I hope you come up with some other analysis on other issues, I'd like to see what you come up with.
Nice video. It seems like an elementary flaw to substantially and abruptly reduce the diameter of that piston rod or shaft especially at mid length. That will certainly create a stress riser potentially creating microfractures that will eventually progress to failure. Unfortunately all semiautomatic rifles may be outlawed before these guys get their problems fixed.
Amazing explanation, I know nothing about the engineering behind firearms but your video was able to teach me so much!
Fired over 1500 rounds out of me WS-MCR and haven't had any issues so far. I've taken it down to the individual parts and put it back together several time and everything seems good for now.
That is exactly what I said but probably 5000 rounds. Then my piston blew apart. Lol. Hoping it hasn't caused further issues I was having feeding problems afterwards. Waiting on a new piston to find out
@@87brandon1 I'm thinking I should get some spare parts just in case. What gen is your MCR?
I think that your analysis is accurate. It seems as if they designed the system without considering how the piston would flex. The fact that this issue is still a problem with the Gen 2 version of the 180c, Kodiak needs to do some serious soul searching and decide if they really want to be in the firearms business.
How could a company designing a rifle not shoot two thousand rounds through it before mass production. Biggest scammers wk and m+m m+m can't even go ten rounds
Solid analysis. Great video. Let us know if we can do anything to help test any further theories you have!
Thank you!
Nice video. I think the best option would simply be to covert it to a DI system. Spectre ballistics supposedly has a DI bcg in the works. I’m hoping to pick one up when that gets released
no thanks. 99% of western guns are ar180 based action for a reason
Excellent analysis!
Awesome video! I have very limited knowledge but this definitely added to it! I have a WK-180c gen 2 that has had this issue recently. I almost wonder if someone has gone as far as to machine an aftermarket piston that could replace the stock one in the rifle. Or if that's even possible. I'd be willing to test new options, I definitely don't want to be replacing it every few hundred rounds.
A most informative look at something I never knew about.
It's baffling to me that _everyone_ seems totally unwilling to actually do what needs doing to fix the issue: replicate the multi-piece piston that the 180 had to begin with. Instead, WK and WS keep fiddling with the existing, flawed design, and Crusader just decided to make it gigantic.
THE KING IS BACK! Love your coverage of lesser known modern firearms, any other firearms you have your eye on? Love your coverage of CCP firearms, bravo!
Haha thanks! I'll possibly do a video on the QSZ193 or the QJY201 in the near future
I was going to wait to buy a type 81 but I think I’m going to buy the WK 181 thanks for your informative video.
i believe Kodiak implemented a better design of the piston system in the WK181 gen2. Kodiak claims it was needed for 7.62x39 ammo, and they are saying its not needed for WK180, but I think the WK181 piston could be used on the WK180. Please have a look at the WK181 gas system.
Yep, I’ve seen that one. It does look like the 181 piston would be an improvement
15:07 I have a technical questing roaming my had for a while. A gas piston is an accelerated mass am I right? And according to Newton all accelerated masses will create recoil impulses? Will an accelerated gas piston do create a recoil impulse that acts on the gasblock pushing it forward?
I would say yes, but it’s not a separate mechanism to what I said in the video. When the piston is pushed back, it does mean that the gas block is pushed forward, but the thing that pushes both these objects is the gas pressure within the gas block
@@cabbage6015 Thank you very much. I also have another question about a longer text, that often get deleted by RUclips, can I contact you on Instagram to set it to you?
@@Grasyl yup for sure!
Awesome video
The FN FAL is one example where a one piece piston is removed trough the gas block.
That's true. I guess the difference between the FAL and these guys is that the Canadian 180s must cram that system under a AR-15 sized handguard
Great engineering video.
Genius dude!
My gen 1 came from factory with a pinned gas block and I have no idea why. I've never seen another one like it.
Oh that's interesting
Having a piston that is the same diameter across the entire piston is important to have consistent stress buckling, but it's cheaper and easier to make one that is thicker.
Regarding the cracked part you encountered at work, what material was it made of? Steel shouldn't be that notch sensitive, but if it's aluminum or titanium it would make a lot of sense that machining mark notches expand over time and crack the part. Just my layman's understanding of crack propagation/notch sensitivity.
With your first piston rod fix, I think it would benefit from a guided sleeve on top/built into the barrel nut. This would minimize maximum deflection under recoil. Think of it like on an sks. I finished watching your vid and see you discussed it. Lol.
Ok, I got my T65 out of the safe. It's a 20" M16 length gun, with an M16 length gas system in AR18 style.
Its piston is in fact thinner in diameter on the spring portion than the portion between the spring and the cup. Not by much, but it is. I'll send you pics on instagram. Also, from the wider section that the spring rests on to the thinner section the spring surrounds, the angle is literally 90 degrees. This rifle is about 50 years old but the piston isn't bent. HOWEVER, the difference in thickness between the two sections of piston is much less drastic than in these Canadian AR18s.
A further note is that the literal piston at the front, the cup that goes in between it and the pusher rod, and the pusher rod itself, when all connected together, CAN BE BENT. This means it's possible some of the bending is released effectively by these portions as joints. Notably, these Canadian 180s are ONE PIECE and have no equivalent joints.
Yep lmao, already see this is part of proposal 1.
It is unlikely proposal 2 is patented. It's existed for like thirty years (G36, HK416) and people have successfully legally made clones of it (Titan Defense 416 uppers for instance)
Yea I noticed that the front section of the piston in the T65 photo is a bit thicker too, but I think it's still demonstrates the point so I didn't pay too much attention to it. I'm kinda surprised that there is no fillet at all though. Also if you can, would you mind taking the diameters of the T65 pistons?
@@cabbage6015 I'm not sure if I have a way to precisely measure diameter but I'll check if my dad does. It will at the least get vague measurements. The other changes in diameter on the T65 all have fillets.
All the models here are . 223 or 5.56, I got a ws mcr in 7.62 x39, and it came with a pistón cup like in your last suggestion, ws mcr does not have a manual they are too cheap to provide one in order to find out torques or any more info
Good luck on your dream job👍
thanks man!
Cool video! your stuff always tickles my noggin! I have trouble understanding how proposal 1 would reduce the bending torque on the con rod tho…
If you had two sections of a pushrod with a guide at the contact point that guide would constrain the radial freedom of movement and prevent one rod just slipping past the other one. The guide would transmit radial forces to the pushrods and the only bending torques applied to the rods would be those caused by buckling, which would indeed be much smaller due to the shorter aspect ratio of the rods.
Your proposal does not feature such a guide though. In that case a system with two pushrods (in the mech. engineering sense of the word) would be under-constrained. The joint between the two sections of the con rods would have to restrain the relative radial movement of the sections by transmitting a bending torque between the connecting rods, which would mean that the stresses from that torque would be just as large as in the original design.
The only workaround without a guide I can come up with, is to loosen the fit between the two sections of pushrods to the point that it would allow enough relative radial movement as to not transmit any torque. But that would mean that the system is now under-constrained and that the gas block and the hole in the receiver would have to transmit the torque to restore a fully restrained system. That would mean increased wear however - Especially between the hardened steel rod and the aluminium receiver - and might lead to jamming of the gas system.
Am I overlooking something?
I’m definitely least confident in proposal 1.
My train of thought is that, bending of the piston rod is produced by traverse deflection of the barrel, the amount of which will be the same regardless of the piston design. So if there is some clearance at the joint between 2 rod sections, some of the deflection will be taken up by that clearance, and the parts themselves will deform less, resulting in lower bending moment. The clearance should not be too much that the radial motion of the rod ends is completely unconstrained. The “cup” feature of the rear rod should contact the OD of the front rod once a certain amount of deflection is achieved, and ideally this amount should be less than the deflection of the barrel. I had some concern with that cup feature. Just due to how small everything is, the walls of that cup will be very thin. So I intentionally used a “normal” drill bit with an angled point to drill the cup. My hope is that the conical surface at the bottom of the cup, when pushed against the conical end of the front rod, will exert a force that helps push the two rod sections back into alignment, thus reducing the stress on the cup wall (but honestly idk how much it will help).
You’re right that the clearance between the two rods might increase the wear on the receiver. If you look at 9:37, there is a brass bushing between the receiver and piston rod, which is shown in my CAD as well (I believe on some guns this bushing is nylon). So the receiver would be protected at least, but the bushing might need more frequent replacement. There is also an option to use a steel bushing, which I believe is what the HK 416 uses. That is also partly why in Proposal 2, I made the spacer recessed inside the receiver, so that it acts as a bushing and becomes a consumable part.
But yeah, Proposal 1 is definitely the most sketchy, and the cup feature of the rear rod can potentially become a new breaking point, not to mention the increased wear. My intention with Proposal 1 is that the implementation is as simple as possible, and that’s the biggest selling point. The low performance is the biggest trade off.
@@cabbage6015 hey sir you seem very knowledgeable. Just wondering if you recommend a certain AK style
The trick, and it´s simple, is to use a hollow shaft, a tube as it were. This way you increase buckling resistance without an increase in weight. The ID would give you the opportunity to house a spring and locate other elements into it like a cylinder where the gas could expand it. Get it?
As a hunter this video just confused me so sat in a blind to ponder.
I think your analysis is right but he problem can be solve with a simpler solution. Add a stop so that the piston doesn't over compress the spring. Increase the rounding at the diameter change. Reduce the diameter of the front portion to equalize stiffness. Choose a material with higher tensile strength. If necessary, add a guide to reduce buckle.
The other solution would go to a SCAR type architecture with the spring and piston inside the gasblock and a connecting rode attached to the bolt carrier with a guide mid length of the barrel.
Great video thank u
Please do some videos on not so known guns of other countries like Korean daewoo k2, Indian Insas rifle etc.
I wonder if the Crusader Templar has a better system. I hear its 3/8" in diameter vs the WK piston which is 1/4" diameter
Take a look at the adams arms piston kit..
I don't understand why they don't use a rifle-length gas system. It's not a problem on the AR-18 or the very long SVT40 and SVD, even the beloved SKS, so why the carbine-length system?
Cheaper for mass production.
I wonder if I can get a machine shop to design me a custom thicker piston rod?
I've been holding off on a 180 due to part breakages too.
If a retrofit will address this issue I'd buy a cheap gen1 or 2.
No way I'm spending over 2000$ on the new Templar though. It also looks way too heavy
The Templar with a fixed AR buffer tube and milspec trigger is just 1700 tho. But yea I handled one at Taccom last weekend. Can confirm front heavy. But honestly I don't think it would be much worse than a Type 81
Looks heavier but the Templar is actually lighter, according to the website.
Interesting stuff.
I used to have to do the same for pistons on hydraulic actuator systems... Too many stripped or cracked threaded sections from where customers used them improperly or overstressed them in new applications... Cowboy lawnmower drivers taking them off high curbs and screwing up the steering rams😅
What do you think about the G36? It's also basically a AR180 variant. I'm also Canadian and thinking about picking up an SL8
Oh please do if you have the chance. The G36 is a proper military rifle adopted by multiple countries, with a robust gas system. The gas system problem mentioned in my video only applies to the rifles I mentioned and other with similar piston designs. The G36 is not one of them
The brn180s likly has a thicker piston due to the increased gas pressure where the gas port is located kn the barrel vrs lower gas pressure further down the barrel.
I'd imagine that the higher pressure is counteracted with a smaller gas port, but that could be it as well
Can you analyse the Crusader Arms Templar? It's got a beefy piston
What's weird to me is that I can tell externally if a rifle was made in Canada for civilian market due to the new laws. Random little things like screws and a weirdly high number of flat surfaces.
I was even able to sniff it out before researching one that was available in the US, too.
Wait? I didn't know that they're available in the US. I think the Templar at 14:26 will be tho. Also yea if you find a WK180 or WS MCR in the US don't touch em. You guys have way better options lol. Even in the modernized AR-180 niche the Brownells ones will blow these out of the water.
And yea honestly the high number of flat surfaces and screws just screams low-cost machining to me lol.
@@cabbage6015 Yeah, the Templar was the exact rifle I was thinking of. The back of that thing's receiver just makes me want to run.
@@cabbage6015 Sooch00 just did a review of the Templar. They are actually setting up shop in Michigan for the US market. And marketing to the US by sending out for review by the content creators on RUclips.
Overall I do agree with your remarks. I think the big part is the choices in metals. They are tough and wear resistant but lack the ability to flex. I had a NEA15. Barrel was very accurate until it wasn’t. It cracked after a few hundred rounds under muzzle device. NEA/BCL replaced it no problem with a new barrel. My gunsmith informed me that it was a common problem being too brittle. I hade to eventually rebuild the whole rifle from the receiver up.
I do think a simple redesign to the original 180 piston assemble that can be a drop in upgrade could solve the problems.
i like the way you think
Hey Cabbage! What do you think of turning down the heavy front half of the piston to the same dia as the rear spring section. Obviously leaving the piston head at full 1/4 like the sks and leaving a shoulder for the spring to push against. Thoughts?
Hmm the rear spring section is really small, I don't know the exact number but I'd guess it's about 3/16" or smaller. I'm afraid that if we turn the whole piston length to that diameter it would buckle in a heart beat. I would say that as we reduce the front section, the # of cycle to buckling failure would decrease, but the # of cycle to fracturing at the stress concentration would increase. Maybe there is a diameter where these two #'s are the same, I'd guess it's somewhere between 1/4" and 3/16"
@@cabbage6015 really appreciate the advice. I ordered a second piston and will have the machine shop chop ahead of the fillet on one and at fillet on the other . I will have them drill out a cup on the rear peice and turn down a male end to mate with the cup for forward peice. Will report after a few hundred rounds. Could be a few months
@@matthewmartin9313 Oh damn, I'm really anxious now, I hope my proposal doesn't fail miserably lol. If possible, please make sure that the surface is polished afterward such that there is no machining marks. And thank you for the effort!
Are you guys able to buy our BRN-180 from Brownells up there? If so, maybe this would be a better rifle. Since it is a very close copy to the AR-18.
Lmao you wish, anything AR and AR compatible is banned
Hey Cabbage, what do you think of the Templar by crusader arms? Would the thicker piston further impede gradual deflection?
I'm not sure if the small dia' portion of the piston is the same as the WK180.
Seems like the SAI R18 Mk2 might have the best piston design on the Canadian market.
I think the Templar is better than the WK180, but the thicker portion would again transfer most of the deflection to the thinner portion. It would be better if they reduce the diameter of the thicker portion.
Yeah I also agree that the R18 piston is the best. The upcoming SRV2 from Black Creek Labs is the same design as well.
However I would add that there is some issue with the R18. My local range rent out 3 R18s, and all of them has developed some short stroking issues after some time, with 2 failing to cycle every single round, effectively turning them into bolt action rifles
@@cabbage6015 Thank you for the input. Ive been considering purchasing one of those two rifles and I'm almost inclined to buy a templar and reduce some portion of the templar piston on a lathe equal to the smallest diameter, keeping the features to retain the spring. They seem to have good reviews from what little is out there.
And it would also also be interesting to know why the " regu
(Zooms in on cabbage in a farm)
In your opinion do you think American made civilian firearms have relatively better quality than Canadian?Because I’ve heard a lot of different Canadian civilian guns having issues more so than American made firearms.
Oh absolutely, the US probably has the biggest civilian firearms market in the world. They also don’t have to worry about their products being banned on a whim the day after release, so they’re less likely to skim on R&D. I have no doubts that US-designed civilian firearms are leagues above Canadian ones.
Can’t you guys get sig 516 or T91 upper?
Nah, AR-15s are banned in Canada, and that includes anything that fits on an AR-15 lower
Eugene Stoner Fixed everything when He designed & Built the Stoner 63A.
Shit.. i wasn't only one think designs like these.., only thing keeping me from is im not good with 3d models..
Why are you not the chief engineer for these firearms? Anybody that would dedicate this much time with detailed information and computer generated analysis should be. Their engineers shit the bed big time. I feel R&D must have been minimal at best to rush these out the door after the ban. Anyways great job, thanks for posting why so many are failing at such low round count.
Many small gun companies don't have "engineers" per say - rather tinkerers and machinists who may or may not have an understanding of physics, stress, fatigue, etc.
There is not that many options in the Canadian marked and they r one of the cheapest so people will continue to buy it they do not care
I really hope the Crusader Arms Templar would be better. It's only 200 bucks more than the WK and WS. Their piston design is still the same sub-optimal geometry but hopefully it's so oversized that it wouldn't be an issue. Black Creek Labs is also coming out with a non restricted SRV2 and that looks much more promising, I just hope that the price will be sub 2k...
@@cabbage6015 yeah, I might get the
Crusader arms eventually but for now I gotta stick to the type 97
Amazing man! Keep on good work! I wish there was more than like/subscribe I could do to appreciate
T91's gas piston is a tooless front removable self contained unit,which I consider to be a better design than even the HK416,and I'm really biased towards the HK416(just see my profile pic lol
Solid rifles for more price in this category !!!
There are reasons why most of AR18 based gun choose to change the original piston design.
I wish there were more AR 180 clones in the US market. I want to start a collection themed around Far Cry 2.
And HK G36 Piston Gas System.
DI Mafia sabotage must be considered also.
over gas, alignment and shitty heat treat is my guess
the natural evolution of the ar18.
i always thought of it like ar18> g36(18x2=36 hehe) >416
Why not use SKS piston system?
There’s a reason why AR platform moved away from 180 system. Too complicated and many problems with pistons.
Why not direct impingement if nothing else?
When certain weapon systems are developed you usually have government involved with almost limitless amount of cash. This usually gives engineers enough time and support they need to develop a reliable system. This also means they have a lot of testing done to ensure dependability of the system they are developing.
In this case a firearm system that was abandoned decades ago due to its reliability issues was RECYCLED because it had to comply with new gun control measures.
Gun companies wanted to make sure they could continue making profit and by using already developed systems to reduce the cost of developing a new system, they simply ignored the fact that this "recycled" system has many problems.
Honestly I find this very selfish just because it seems like they capitalized on an unjust gun ban and used the opportunity to recycle a system that was abandoned long time ago BECAUSE of design problems and reliability issues. What worries me even more is that no one, NO ONE thought it was weird that we went back to 180.
No one would even look at this system if a gun ban was not introduced so if you, gun manufacturers in Canada honesty wanna help Canadian firearm owners and give us options until this unjust OIC gun ban is resolved and if you wanna use already developed reliable systems please, use the ones that actually work.
Awesome Video. Wk-180c are garbage rifles. Don’t waste your money
I have never had one issue with my Gen 1.
How many rounds? I haven't had any problems yet either (knock on wood) but I've probably only got like 300rounds threw it
Yeah, my gen 1s still going strong. I didn't even know bent pistons were a thing with these until today.
the 416 is a good replacement, if it is a direct replacement, are you working with someone to manufacturing it yet? If you are interested send me a DM
thank god canada has immigrants
wk180c worst gun ever. TNA should have started over with this cheap ass gun. I had to modify the whole gun so it would be reliable . the type 97 5.56 is wayyyyyyy better if you like bullpups.
No way r u Canadian
Not a citizen, but I do live in Canada
@@cabbage6015 that’s cool where r u from
@@wall7171 Vietnam 🇻🇳