Failure By Design, Axe Handle Design Mistakes and Improvements, *Spread the Stress*

today's video is relevant to both axe users and axe manufacturers and it could save a lot of handles we're going to talk about things like transition and size and shape differentials and what some factors that can go into causing breakage this is based on a viewer comment that I was trying to answer and it's not I'm not going to talk about that specifically but it just got me thinking about the problem then this would make a good video and explain these factors and give some suggestions to how to make both manufactured new axes better when the handles come off the lathe all the way back to the user who you should really count on having to do a little bit of work on the handle unless you're buying some really high budget axe and even then chances are you probably gonna want to do a little bit of modification to the handle okay my viewers problem was that he broke two handles in a row the first one broke immediately the second one that he put on and spent a bunch of time broke shortly after that he said one of them definitely sheared just right across like this and another one he thought the other one was similar but he wasn't sure so I wanted to describe to him some of the factors that go into that and some of the possible solutions and that led to that was the genesis of this video okay so here's the problem and this is an inherent problem we can only solve it so much so we're just like making it the best we can to deal with something that will never be ideal or never be perfect okay so we have a heavy mass on top of a relatively weak material you know there are other reasons that we use wood but inherently it's a fairly weak material like for instance fiberglass would be much more durable the difference in the mass between this material and this material you know this is like concentrated in a small ball of heaviness here and then this is relatively light is an inherent problem another common problem is that this straight line here forms a kind of a sharp edge like if I wanted to to break this handle by bending it and I was going to push it against an edge if I push it against a straight sharp edge it's more it's more likely to break right now commonly when of axe breaks this way or this way it's from side impact so if you're cutting into a notch when you're bucking or felling and you slam the axe head into the side of the cut like say this is a sloping cut in Sipho the tree that you're cutting down you slam this well suddenly this heavy mass changes direction really quickly and for whatever reasons that I don't understand this doesn't keep up and that causes you know this to failed now that's gonna be important when we come back to it that also can happen in limbing so if you're trying to cut your limbs close to the trunk which you should and you you swing for the bleachers you slam the axe head against the trunk then that can cause the same problem of suddenly jumping this mass in a different direction and since this mass has a lot of embodied energy it's carrying a lot of energy that some doesn't work that's why it cuts when that changes direction it can wreak havoc here now sometimes that split will just be like it'll kind of split off the side a little bit and form a crack that like a slab and other times it will just cheer right off another one is crying with the axe so let's say you you're splitting something and you get the axe stuck and you know that if you just you know you can use this handle and pry that thing open and pop it open like a lever you do that you hear that sickening crack and it's all over I would never say don't do that because I do it it's just a matter of learning the limitations of the handle and that's usually gonna involve hearing that sickening crack more than once when your handle fails okay so there's a problem you know I had a conversation with rooster in the comments Craig roost from axe drunkies shout out to Craig rooster awesome and he was saying that the ears on some axes like this served not only to increase the the surface area of the contact with the handle which is a good idea because the smaller the more this is cut off in the smaller the surface area inside the eye the more likely is to come loose but also that when you bend against this it's less likely to shear than if you bend against a straight edge like this now that immediately made sense to me intuitively when he said that but I still don't understand the mechanism of it entirely but that's okay I think he's right okay so now let's get into this stuff down here because how this is shaped these transitions the differential in thickness the difference in shape of the wood in this area in particular and going down to the rest of the handle has everything to do with how much stress ends up being applied at this weak point okay look at this caricature of an axe handle and head so this is the back of the head now look at that and imagine using this ass imagine this is a baseball bat I think that's the best analogy because everyone's familiar with the baseball bat like there's a problem here what's the problem the problem is the differential between the size of this where it comes into the eye and of course you know inside the eye it's only it's only this big and so right here this is a weak point right because it's the thinnest point it's the thinnest weakest point of the ox is this this here when stress is applied like that now the differential here makes all of the difference haha stress is applied to this system let's say we have you know a line through here and stress is applied across this line then what's gonna give right access not gonna break this is incredibly thick it's not even gonna flex it's important it's not gonna flex this is gonna flex and then it's gonna break why because it's only flexing right here this is like barely flexing at all it's almost insignificant if we start to take this and reduce it every bit we can reduce this differential in my view this is all theoretical but you know I feel pretty strongly about most of it now how's that we still have essentially the same problem we've just improved it a little bit you know we have the mass of this is also problem but it has more I think to do with the flexibility so now this is slightly more flexible but there's still a huge differential between these two it's about 50% so they say this is twice as wide as this is and that's too much also we have our handle sticking way out here which is right you don't want the shoulder sticking out a quarter-inch each or even an eighth what's let's do this okay we're gonna pin this down we're gonna say okay now it's approximately the same thickness right here as the Ox head width right we have this win trite here and we're gonna make this part of the handle the shoulder the same now we do want this thicker than the eye because when the axe head comes down it needs to see against something so this needs to be a little bit thicker but we don't want it in my opinion we don't want it thicker than the head and we're gonna come down a little like most axe handles view although some don't come down very much I don't know my own strength I keep breaking the chalk much better now this is going to flex more what happens we apply a stress here we apply a stress across this direction and in any way instead of just bending here some of the stress is going to be shared out in bending this now how far you take this and make it flex more to share more of this stress is another question my theory is that the more that this flexes the more stress it takes off of this point right here okay so here's another problem transition now we have a we've we've reduced this and we've improved it I mean I would send this down a lot more but we'll talk about that maybe in a minute or maybe not but this transition is abrupt and sharp you know we have a pretty sharp angle right here and then it jumps over here quickly and what does that create that creates strain run out so we've cut across the screen like this okay now the sharper this transition is here the more likely this is to break and we can make it more gradual that's a benefit this is a very common breakage point right here why because we're violating the grain like this and we've got a situation where this is more flexible this is less flexible because it's fatter so it's stiffer and it's going to move less and we apply stress say like this and this just separates basically like that now this is even worse if you see this where instead of coming straight out of the eye like that this makes a shot in sudden transition out fewer say like 1/8 or 1/4 of an inch try to get rid of that let's say we have that now what's going to happen when you hit your axe on a piece of wood here you can think of it as stress coming back up this way pushing on this accent so suddenly you're heavy ox head stops the handle is gonna flex this way and this can pop open right here along the line and just unzip so get rid of that I mean to me the ideal axe handle comes straight out of the eye this is the eye and it goes in a straight line and does what it does from there if it doesn't this should be a very gradual you know and not too sudden transition to a belly like that if you want the handle to come in like this okay so for whatever reasons making these transitions more smooth is beneficial so I'm gonna take this and I'm gonna look at it and I'm gonna say why the hell did they have this come way out here like this what purpose does that serve get rid of it if this handle ever comes loose you want to be able to tighten it so you need a little bit of shoulder left here when you finish the axe and you need a little bit here you don't need very much like let's say this could just come out like this much we're gonna make this transition a little bit smoother so now we have something hopefully that comes relatively straight out of the chute here very little curvature here smooth transition so there's nothing too sudden and now we're talking sorry this eraser doesn't work very good but it's brain tan - buckskin okay so the cool factor on this eraser is extremely high you know to me I like thin handles look I have something this is a great handle here this is westwoods and all I don't think I thinned this or scraped it very much I think I just worked on this transition here because like all manufactured axe handles out of the box it needs work in this area this is a great example of what I was talking about so let's take a look at this so as he suggested and I totally agree take as little off the front here as possible just leave out in a nice straight line it might curve down slightly I'm not sure but I can't tell from here no matter it's smooth it's even now back here this barely is any wider than the eye itself it's just a little bit so I can jump this down in the future if it comes loose I can fix it that's cool not too much and this slope is relatively even here this also thin this way so we've changed the differentials between the masses the mass of this zone right here which is inherently weak and this mass has been reduced the difference in shape the drastic differences in shape have been reduced and the differences in flexibility have been reduced so while this was you know much more flexible than this now this bulky area which is inherently inflexible and inherently a problem is now less different it's left it thus different and flexibility then it comes down into this nice thin handle here when I use this acts even swinging it the mass of the axe is gonna cause a lag in this handles gonna flex it and when it hits stuff the handle can take more stress like this is all moving even this is moving and that puts less stress on this part of the eye isn't that cool with that understanding we can go a long way now let's look at the same thing from the other side there was still much more thickness this way than I want so I did the same thing I want this to come down until it hits an area that's just a little bit thicker than the eye width so it's gonna stop it's gonna nest here this is super important to have a really tight nest right here at the bottom of the eye against and that requires that you have somewhat of a shoulder also I have enough room both in this direction with this thickness and this width right here left that I can jump this on probably three-eighths of an inch more if I have to in the future like say if this handle gets shrunk or for whoever owns it you know how for me which will be one of you because we're gonna give this axe away when I'm done with a handle chances are that the eye width and this width are not going to be that different you know maybe depending on the axe but they're more close to equivalent you could even argue maybe now that this area is stronger because it's wider and it has more strength in this direction but it still probably has a little bit less strength in this direction than here and also because again you have this transition here with a sharp edge and this heavy mass like we've seated right here for instance if I were to bury this in a log and then I took the end of the handle and I pushed on it and pushed on it until it broke chances are it's gonna crack here first and that says a lot okay now with this handle I didn't have to do that much I definitely did some work up here I took quite a bit off here I took quite a bit off here I took a lot right in this area because this came out much further than I wanted and then dropped down no that's a problem and none of it was a ton of work but I didn't I don't think I thinned this down at all if I did it's not very much whatever I had to do to this handle was not that much because this handle comes close to what it should be in the first place like pretty much any new axe handle unless it's a company that's really doing a bunch of finish work for you you're going to have these kind of rough cuts and transitions now this is a council 2lakhs and they actually do quite well with this - again I don't like this excessive thickness here that's gonna come down this I want a little bit thinner so that's going to come down but I'm gonna change you can see the sputter here I'm gonna change this differential and thickness between here and here I'm gonna smooth these transitions but really they're not that bad they're pretty good in the socks here but you should still do that when you get a new axe start to smooth all that stuff off a great tool to do that with I don't have it with me is shoemakers rasp okay so let's look at this handle from house handle and aside from being incredibly crooked it has this you know gross transition here of thickness where this is hugely fat much much larger than this like any full-size axe like American axe that you would put on this which is what it's made for this is gonna come stick way out you know thicker than the head itself this is exactly the problem I'm talking about the transition is not that smooth unlike and say on the counsel axes you can see that this slope comes down and it's actually milled all the way down to this point here whereas this one you're gonna mount about to this point here and then that transition is only maybe a half inch or less long my complaint with manufacturers is not that you know everyone no one should have to do any work to their accent oh that's the best what we find is expected you should do that it's like personalizing the thing and tuning it up and getting it ready for your your particular use what I'm saying is that drastic mistakes like this are costing breakage and handles you're leading to breakage people don't they buy an axe at the hardware store even if they're looking at stuff on the internet you know they in trying to educate themselves they might understand these things and this is leading to breakage probably the worst example I remember seeing is snow in Ely which the handle was even thicker than this handle which has almost no flex to it that's significant you know when you're using the tool it just you know it came way up near the shoulder and then suddenly it Dogen just like I had drawn this earlier now the super thick handle and it just suddenly dies out like this and then it comes down and it stays almost as thick the whole way down where this doesn't flex he has a sudden transition don't do that okay I hope that gives you an idea of what to do with that tool I'm gonna go get a shoemakers rasps I can show you okay here it is the shoe makers rasp sheer ass for whereas four-in-one whatever you want to call it these are infinitely useful for shaping wood bone antler you know stuff like that that's not too hard I would not use them personally on metal I definitely wouldn't use them on steel because you're gonna wear out the file part and it won't be as useful for your wood working needs these are great for shaping these transitions making handles spinning handles unfortunately I can't recommend a good one I've been on Amazon looking at them and short of basically spending I don't know probably a couple hundred bucks ordering every one on there and doing comparison which I would love to do and I hopefully will do in the future I just can't recommend one I like this size here if you're going to do portable you could get the next size down I think this is an 8 so it'd probably be a 6 inch you

Channel: SkillCult

Views: 18,714

Rating: 4.9491258 out of 5

Keywords: axes, axe handles, axe handle design, thin axe handles, thick axe hanles, Axe handle shoulder, replacing axe handles, new axe handle, hickory axe handle, tuning an axe handle, Axe handle modification, single bit axe handle, double bit axe handle, axe junkies, woodcraft, bushcraft, council tool, husqvarna axe, West Woods Axe handle, axe eye, broken axe handle, preventing axe handle breakage, prepping, skillcult, Steven Edholm

Id: DrghRcqbVis

Length: 18min 14sec (1094 seconds)

Published: Tue Mar 13 2018