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Aiden CC

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Everything posted by Aiden CC

  1. Thanks! That sounds good. I did manage to find speeds for 17-4. The mill I would use is a knee mill with CNC on the X/Y axes. I'll probably just be drilling and counterboring manually, but if I get ambitious I may cut the profile with CNC (though using a bandsaw and grinder might honestly be less hassle). Was the knife a liner lock or frame lock? I'll keep looking into Ti, though it is a bit of a pain to work, especially if it were 3/16-1/4" thick like I plan on making the frame. Do you have any pictures of the knife? It would be interesting to see how the replaceable contact point works.
  2. I believe most of the stuff I’ve seen has been in the solution treated state. After aging does it behave anything like a lower alloy steel would at that hardness? That’s a fair point about McMaster. I looked on eBay a bit and couldn’t find much Ti over 1/8”, which is a bit thin for what I want to do. I have also experienced the galling Ti can exhibit with steel, though I found that applying then wiping off oil mostly fixed it. Is the replaceable surface on the lock bar or on the blade? With a frame lock there’s a lot of lock bar to wear, which should help longevity.
  3. Not having to work with hardenable material could make machining a bit easier. Hopefully with a thicker lock bar (3/16") and some angle to the heel it will take a long time before wear is an issue. I don't think I will be able to leave anything unhardened on the blade since I will likely do a plate quench, but since I'll be using foil, there hopefully won't be too much damage to the surface and I'll be able to go closer to the finished geometry before heat treatment. The over-extension thing is a good point, since there isn't a scale to stop the travel like in a liner lock. It looks like heat treated 17-4 has over twice the yield strength of a 300 series stainless steel, which could address that, but maybe I should do some analysis to see if I really need that strength. I was planning on using washers made from some kind of bearing bronze, and either a pressed in bronze bushing or a bronze pivot for the action. Not as sure about a bronze lock-bar. The elastic modulus is lower than steel so I wouldn't need as deep of a relief cut, but over-extension could be a problem and I would be worried about permanently bending the lock bar on accident.
  4. I've wanted to make another locking folding knife for a while, and thought that a frame lock might be a fun project. I'm trying to keep the budget manageable, so that means in all likelihood using a steel instead of titanium for the frame. I want the whole thing to be corrosion resistant, which means the steel will have to be stainless. I already have some CAD and have picked a few of the parts I might use, which I will probably put in a Design and Critique thread later down the line. Anyways, I have been looking at a few different options. One option would be to use some blade steel, though this might be the most expensive, since I would need to buy a fairly thick piece of steel. It would mean I could make the blade and scales from the same stock, though that would involve more machining, since I plan on the scales being 3/16" with a 1/8" blade. Also, I already have some 440C in 1/8" bar so I don't need to buy blade steel anyways. I haven't looked into it much, but it also seems like getting the properties I want may be difficult in a steel designed for high hardness rather than spring applications. Another steel I have considered is 17-4 PH. It seems like I would have a lot of options if I bought a piece in the solutionized form and that the high strength could work for this application. It's also available in a convenient size on McMaster Carr where I might order all of this stuff from. One downside is that I've heard it can be difficult to machine (although apparently it's better if you harden it first?) which could be problematic since I have lots of drilling and counterboring to do. The final thing I've been thinking of is either 410 or 416 (though these aren't available on McMaster in convenient sizes and I would have to order from somewhere else/use a piece I have which may be big enough). I think the strength on these will be high enough after heat treating. Also, would a 300 series work at all? I'm sure it depends on the spring geometry, but I want something that will work with a wide margin so I don't mess this up. Also I may be able to get some budget from this from my school, so if I can keep it to under $100, price isn't a huge consideration. Any thoughts would be appreciated! I'm currently leaning towards 17-4, but that depends a lot on how it is to machine (heat treatment looks pretty straightforward, just an aging cycle at ~500 C). This is mostly based on it being available in a convenient form and having s simpler heat treatment than 410 (the box furnaces I have take forever to get up to ~1000 C and it would complicate things if I had to do an oil quench), plus if I can get money to buy new stock I would rather do that than use things I bought for myself. If a 300 series would work without heat treating that would be the easiest (though I kind of like heat treating stuff). Thanks for reading!
  5. Looking good! Not sure if you’ve already done the glue up, but if not, you could also carve softwood wedges to fill the gap rather than dust and epoxy. It’s something that was traditionally done on both puukko and Sakha knives.
  6. Burnishing could be a good option. The general idea is to raise "whiskers" on the surface of the wood, then remove them. My personal method is to wet the wood, dry it with a hairdryer, then scrub it with steel wool. I repeat that until the surface of the wood stays smooth when it gets wet. When oiled, this makes for a fairly glossy finish.
  7. Thanks! Thanks! Its my favorite of the two. It has also been somewhat more pleasant to work on. Now, some more progress! First I sanded the carving knife handle through 220 grit, then I marked and cut the first notch. I decided to changed to wider rounder notches, partially for looks and partially because the edges of all of my needle files are too torn up/rounded off to make a decent square notch. The big notch was made with a half round file. This was fun, and took a surprising amount of time. I took a bunch of pictures at the different stages of shaping/sanding this handle, but you can't tell the difference so you'll have to trust me when I say it took a few hours. The angles are very tight, so a lot of the work was using either folded sand paper or wrapping it around the very ends of files. Here are the results! I'm going to try and make a sheath for the carving knife, other than that and a few coats of oil it's finished. The big one still needs a wooden end cap to cover the rivet, then it will be all done. I'm going to try to make a sheath like the very elaborate one of the original, and definitely won't be able to get it done in the next two days while also doing the other things I want to get to. Also, the sun's supposed to finally come out tomorrow, so hopefully I can get some better lighting for more pictures.
  8. Not a ton of progress today, just got the antler on the big knife roughed in. The guard was really tricky. The lip in the sides couldn’t easily be shaped with a file because of the downward curve after the edge, so I had to use a burr on a Dremel. Tomorrow I’ll start sanding, and possibly finish both of these.
  9. I used to use birch bark for this, but have found leather is more consistent and generally easier. For some reason metal guards/bolsters with no spacer looks fine to me, maybe it's because antler and wood don't have as much contrast and need something to go between them. Anyways, here's some more progress: First step was to peen both tangs. The one on the larger knife will be completely covered by a wooden end cap, but this one needs to look at least somewhat presentable. Handle profiles marked out. While peening, I accidentally broke the tip of the big knife, so I also did a slight re-profile to fix that. The handle design I had for the carving knife would have put the rivet a bit too close to the edge of the butt-cap, so I modified it slightly. A coping saw, rasp, and files take the handles to the lines. Same for the other profile. There are a few wiggles I noticed here, which I worked out after taking the picture. I used a rasp and files to break all of the corners on the carving knife. Then I used the carving knife to shape the wooden section of the hunting knife handle. I will need to use a rasp/files on the antler. Shaping the wood with a knife is the way Bergman recommends to do it in his book. It felt a bit slower to me than using a rasp, but then again I use a rasp much more than I whittle, so it could just be me. It was also more fun and chips are a lot nicer than dust. Also, the leather kept the edge from hitting the antler which was nice. It also might set me up for an easier time shaping the antler, not having to worry about the wood as well. Anyways, that's it for now! Next step is to finish rough shaping then move on into sanding. Thanks for looking!
  10. I have about two weeks of time to put in some serious work on knives, this is some of what I've been up to. These knives are both based on knives in Bo Bergman's knife making book, one of them a project (the Mountaineer's Knife) and the other one is inspired by a drawing of one of his wood carving knives. Here are the blades plus a drawing of one of the finished knives. The puukko and small carving knife are both forged from an old leaf spring, and the third is 80crv2. The puukko will have its own stuff going on, so I will probably make it its own thread when I get to working on it. This is the plan for the carving knife. I decided to make it because I'm not really happy with the last one I made. It also had a scandi grind, but was a bit too acute which made it too high maintenance. Now I use it mostly for leather working. Because the pieces of the handle don't all have square edges, it is important to use a pattern for the handle shape and mark out where the tang will be so all of the drilling is in the right spot. Also, I used a lightly different method for cutting these handle blanks from the parent stock (curly birch planks from smaller trees, which are much cheaper than blocks) and should hopefully get a better looking pattern on the surface of the handle. Here the blade is polished/sharpened and everything is epoxied on. I'm trying out the method of gluing before peening. It usually takes longer than the working time of the epoxy to peen a tang anyways, so I figure this will save some pain and suffering, though I think the angled surface of the bolster will add some back. This is as far as I have this knife right now, I will probably peen the tang and start shaping the handle tomorrow. The guard for this knife goes out fairly far, so the antler was cut from the widest part, a few inches above the crown. Since the top surface curves down, I shaped that before fitting it to the handle. This guard was a real bear to fit. The hole isn't square since the blade has no plunge cut, and working a 1" thick piece of antler with needle files takes a while. I do think it is my best fit of an antler bolster though (especially compared to the carving knife). Here you can see how I made the hole for the tang in the birch before trimming it to final size. Since I had to drill the hole from both sides, it was much easier to do with a block I knew was square. It was easy enough to trim and true up afterwards. Here is the whole stack put together. Right before this step I sharpened and stropped the blade. Also, in this picture you can see how far from square the antler butt-cap is. This meant that the hole for the tang is not 90 degrees. I used a hand drill to start it and was careful to check that it was parallel to the matching face of the wooden block while fitting it. You'll also notice some pieces of black leather. I find adding leather helps to improve the look of the transitions in the handle, I find that even if you get very flat surfaces it doesn't look as nice as if there were a spacer. That's all for now, hope to have more done tomorrow. Thanks for looking!
  11. I’ve found that if you put the blade between two planks after the quench and stand on it/clamp it you can prevent some of the warping you get with the asymmetric grind.
  12. I haven't had much time for knives lately, but did manage to work in this project. I did it with a team of three other people for an end of semester mini-project for a materials science class. I think this video introduces it pretty well: The knives are made from mild steel carburized with either Cabot seriously sharp cheddar or pecorino romano cheese. We made a total of six. Credit to my friend Ricky for the video editing as well as the design of the knife. This is some of the cheddar after we pyrolized it. Half of the blades were carburized with powdered cheese charcoal and the other half with straight cheese. Both methods yielded similar results. We packed everything in stainless foil pouches and soaked at 925 C for five hours. Unforunately the cheddar charcoal pouch deteriorated and let in air which led to a slightly lower carbon content than the others. We also put a dogbone tensile specimen in each pouch and have some mechanical data I may put in a post in the metallurgy section of this forum. The grinding and polishing was all done with a bench grinder. I still have an un-ground blank I'm going to put a proper grind on in my own shop. Still, for a rush job with people who were just learning how to make knives, I think these turned out pretty good. The handle scales are galalith, a casein based plastic. This greatly increased the dairy content of the knives. The steel is about 0.4-0/5% cheese by weight from my best approximation (again, the materials analysis may have its own thread at some point). This stuff is very soft and brittle and supergluing scales together for drilling ended up to cause a lot of problems. Here's a finished knife. I will probably post better pictures of the one I finish on my own later. Hope you enjoyed!
  13. Also, is it forged or stock removal? I've had trouble in the past drilling forged steel. I decided to make some test coupons (forged 5160), and found that samples which were forged and then left to cool in air were essentially being quenched from contact with the anvil (with bainite and martensite showing up in the microstructure). You can solve this by normalizing all of your knives a few times after all forging (heat up then cool in air, though for some steels like O1, air is too fast if the blade is thin). You can also temper knives after you forge them. I've used a torch to heat the blade until I get a sky-blue color in the area I want to drill. This isn't as easy on drill bits, but it works in a pinch and doesn't form scale on your piece. Hope this helps!
  14. It's hard to tell with the rust on the blade, but I think it was originally beveled all the way on both sides and a pseudo plunge cut was formed from sharpening. Both sides have the effect, but in slightly different places.
  15. It seems like the parts of fit and finish people focused on were different. In these examples it seems like the handles/sheaths received a lot more attention than the blades (though that could just be from rust/resharpening). I like making knives like this too, but there are some cases where I will take some license and clean things up to my own personal standards, mostly relating to blade finish. Its interesting looking at the originals because you notice some ways the ones people make are different now. One big thing is that essentially all of the blades have most or all of the forge scale removed, while leaving it on the flats of the blade appears to be modern. Additionally, the handles all have simple, relatively large shapes. Its hard to tell, but it also seems like the big knives are a bit thinner than the modern leukus a lot of people make, though that could be because these are from Sweden and I'm used to looking at Finnish leukus. Also, speaking of Finland, I found another site you can search for more picutres like this (although I found fewer results). Here is my search for "leuku," the Finnish word for a Sami stuorniibi ("big knife"). That one is pretty neat! It seems like getting that much antler in that big of a size and that good of quality would have been difficult (it certainly would be now), even for a reindeer herder. It might have multiple crowns in it, and some if it may be from moose, though I'm not sure. Those sheaths with a two part liner are really cool too.
  16. Glad you found value in it! The originals lie on a wide range of function vs. ornamentation, with the two originals I'm lucky enough to have falling at different points of that spectrum: I've found that I'm most interested in the examples representing knives made to see use, I think I want to try making a larger knife with an all wood handle, since it seems like a decent number of the ones in this collection were built that way, which makes sense as it is hard to get pieces of antler that big from reindeer (I've seen examples where people used moose antler though).
  17. Since I haven't had much time for knives or access to many tools for a bit, I've been doing more research, and getting more interested in historical authenticity for my knife designs. When you go to make a knife in a certain style, it's easiest to modern pieces, which perpetuates a cycle and often leads to knives that don't look much like the originals. There's nothing wrong with this, and I have seen some modern takes on classic knives that are absolutely beautiful. However, I have recently been making my effort to base my work on originals when I make a historic style, which can prove tricky. I recently found this source here: https://digitaltmuseum.se/search/?aq=topic%3A"Lapska föremål %3A Personlig utrustning %3A Knivar"&o=0&n=560 which contains almost 200 pictures of old Scandinavian (many of them Sami) knives, so I thought I would share it here. A few of the pictures I liked: I also did a bit of poking around in a search of "knivar" from the website's home page, and it looks like you can find a wide variety of things, including some archaeological finds as well. Hopefully this is the right part of the forum for this, and that maybe someone else can get some use out of all the information that's there.
  18. Like Geoff mentioned, an asymmetric grind can contribute to warping in heat treat, and in some cases, it can be better to save the grinding until after. If you set them down on a surface to cool, that could have contributed to the warping, with the side on the surface cooling at different rate that the side in the air. Either clamping vertically in a vise or handing it by a wire through one of the holes could be a good way to let these cool. It looks like you could try to take some of the warp out in a tempering cycle if you could make jig to force a counter-bend and put it in the oven. As long as you don't overheat the edge, you could try more aggressively heating with a torch as well. If you go the rout of re-quenching, you could try clamping between two flat plates after coming out of the quench. I've done this for some Sakha style knives, which are concave on one side and convex on the other and love to warp. I quench, straighten by hand with welding gloves/a vise, then sandwich them between two pieces of 2x4 and stand on the top. Gives decent results and sometimes I don't have to do any correction in tempering/grinding. That approach might work for these as well.
  19. The most effective time to straighten is right when you pull the blade out of the oil, as the steel takes some time to fully harden (martensite formation), and is still ductile enough to bend gently in a vise or with thick gloves. After that, the best time is during a tempering cycle. I like to temper once at a low temperature (like 350 F) then clamp the blade to a piece of angle-iron with shims to bend it in the opposite direction as the warp. Then I temper again slightly higher (~25 degrees F), and often that is enough, especially for simple warps. If I can't get all of a warp out in one or two tempering cycles, I carefully heat spots along the spine until the oxides turn blue then counter bend it with a three point jig in a vise. The hotter you get the steel the easier it is to undo a warp, but the more hardness and strength you lose through tempering, which is key to keep in mind with these techniques.
  20. When you are working with thin steel, you’re going to have to deal with some amount of warping. I can only think of a couple of times I had a long (>6”), thin knife come out of the oil exactly how it went in. I found that using a larger container for my oil helped immensely (an old ammo can as opposed to a capped pipe), as it allowed for more even cooling. Another thing to note with thin knives is that they will move under their own weight for a brief period while the martensite is forming and they are still ductile (you can also gently straighten them in this phase). If you leave them to cool in a way that allows them to sag, warps can appear from out of nowhere. My philosophy with warping has been to learn how to both prevent and fix it, since sometimes it is almost unavoidable. Do you have any pictures of the warps? That might also help diagnose the problem. Hope this helps!
  21. This is from a project I worked on a little while ago and might be a helpful visual for this topic. These stress-strain curves are for 4130, which is lower carbon than the steels in knives for the most part (though still hardenable to the mid 40s), and shows what some of this stuff looks like in a qunatitative sense. The unhardened samples are very ductile and show a higher toughness, but much lower yield strength. The quenched and tempered sample has a fairly similar overall behavior, but with roughly double the strength and a lower elongation at the break. The untempered sample had too high of a strength for the tensile testing machine (actually, too high of a cross-section) and maxed out the load cell, so I unfortunately I don't have a full curve for it. However, you can see the substantial difference in strength from the tempered sample . By the time the test maxed out, it had already stretched almost 1.5x as far as the lower strength tempered sample at yield almost three times as far as the unhardened samples.
  22. Glad it helped! I always sharpen scandi grinds before assembly. It's much easier to sharpen that way and, as you mentioned, you can get a better finish initially. In old knives, they were often ground with a slight hollow, which eventually gets sharpened flat, and then ends up convex. All of the originals I have show some signs of a slightly convex edge. Knives almost always come off of a sander a bit convex, which you can keep, or you can use sand paper on a flat surface to get it flat(er). This makes the first resharpening easier and look better (since the knife will be flat on the stone). In the past, it seems people cared less about keeping the bevels perfectly flat and just ground it on a stone until it was sharp again.
  23. Like any knife, the profile changes when you sharpen it. Having the grind go all the way to the bolster/handle lets you get a bit closer, but just like with a ricasso, there will inevitably be a little "dip". Some old Scandinavian knives had shoulders stick out above the bottom of the handle which helped with this a bit. An old very well used puukko next to my reproduction guessing at he original profile. It you look at pretty much any knife which has been used and resharpened for years and years, it will have some kind of concavity on the edge from sharpening. I haven't noticed it on any of my hard-use scandi knives yet, but the oldest one is only about 3 years old.
  24. Thank you for the information! I've spent some time looking for the "Material and Spiritual Culture" book (using both the English and Russian title), but haven't had any luck finding a physical or digital copy anywhere (looks like only 2500 were printed). The book you sent a link to had some good information and I found one picture of the knives in it. I also watched some of Alexey's videos, and they are very helpful. It looks like for some of his knives he leaves scale inside the groove (though the inside is always smooth, either forged or filed)? I'll probably reach out to him to ask some questions. Is there a way/place that it is best to talk with him? I don't have a ton of time for knives right now, but I will probably do some drawings and maybe forge a few blades. I have been able to find some decent pictures on line, but haven't been able to find the original source of any of them: I especially like the narrow knife in this one, and may try it. I like the shapes of all the knives in this image, and will probably use them for inspiration at some point. These are such a unique type of knife, that I've really enjoyed, and it also seems like they are tied in to a sense of regional pride/cultural heritage. When replicating old knives I like to put a bit of my own style/skills into the final product, but I try to stay fairly faithful to the original form/function.
  25. Thanks! The puukko was described as being from the 19th century where I bought it. There wasn't anything that jumped out at me to disprove that, but I don't have a good way of actually seeing how old it is. There have been knives that look like that for a very long time. The birch in that knife came in the form of these planks I got from Brisa, and I've found that it is much more figured (and much cheaper per knife) than the blocks that you can buy of the same wood.
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