First of all, I'm a little late to the party, but hopefully I can be of some benefit to somebody reading this thread. I was told about I last night and didn't have time to answer.
A little introduction, I'm Donavon Phillips and have been competing and involved with BladeSports for about 8 years now. I'm going to start by answering the OP's question as best I can, based on my opinion and experience.
Before I start that, here is a link to an older thread I went back and found that may be of interest to some. Most of the information in this post is still accurate, although some things have changed. I will be glad to answer any and all questions related to the old thread or this one.
http://www.bladeforums.com/forums/showthread.php/670087-Cutting-Competition?highlight=dphillips
Let's get started.
Okay so I'm thinking about getting into bladesports and wanna build a chopper. I'm probably gonna go with either 52100 or possibly M4. What I'm trying to figure out is the bevel angle. I know they're usually 2in wide blade made from .25in thick stock(and that's probably what I'll use). Most of the ones I've seen are close to a full flat grind with about a .25in of saber on the spine.
What bevel angle do I need to be considering? Also, what kind of edges are these guys running? Convex?
I'm also looking at using some horse stall mats for the handle. Is there any other material i should be looking at?
Any advice on making one of these would be greatly appreciated.
52100 is fine choice for a first chopper, I started with 5160 and after being around some 52100 later, I wish I could've used that. I have limited experience with 52100. Dan and Jose Diaz have used it with great success. I'm looking into acquiring some A2 for testing, I plan to use it for prototypes and less expensive option to M4, if it tests out satisfactorily. I want to try A2 because from reading and talking to other knifemakers and steel guys, it is a good option for stock removal makers like myself. It is also readily available in all thicknesses and widths and is air quenched. I'm not set up real well in my shop for oil quenching, I don't use enough of it.
Knife maximum size is 10" blade, measured from tip to beginning of handle material, handle material and edge cannot overlap. 2" wide and 15" long. I recommend starting with 5/16" stock. You want to end up with a 1 lb 5-7oz to start with, that's my opinion. The Benchmade 171 falls in this range is one of the lightest blades currently used in our sport. I also highly recommend a tapered tang, this is to push the weight toward the tip for chopping. I would start with a full flat grind and go from there. Cleaver or traditional point will be up to you, the reason we use the cleaver style is to push the weight toward the tip. We don't stab in competitions because of our mission statement, which in short is to promote knives as tools. So stabbing media sends the wrong impression, especially to young people.
Bevel angle I can't give you. Not because I won't, because I don't know. I full flat grind all my comp knives, you could saber grind thinner stock to end up with more weight if you desire. I moved up to 3/8" stock and full flat grind it and try to leave as close to full thickness at top as I can. The tapered tang thickness and length determines balance more than anything. Most of mine are tapered roughly 1.5" in front of the plunge lines.
Edges, this also varies with each competitor, I have found I prefer to grind my blades thinner before sharpening and then put a V edge on them. The shoulders of the V strengthen the edge in my opinion. I used to use a convex edge and discovered this by accident when re-sharpening my blades by hand after competitions. Yes, I re-sharpen my comp blades by hand with DMT stones, we'll get into that later if there is interest.
Horse stall mat is a definite in my book. It absorbs shock and grabs you back when your palms start sweating and your hand gets covered in water from the water bottles. Handle shape is as important as the blade shape to me. Actually, my blade stays the same on my knives now, but I'm still playing with handle drop and handle shape.
I will gladly tell you everything I know, which may not take long, depending on what you ask.
From my limited understanding competition choppers are made ONLY to chop the things in the competitions: golf balls, tennis balls, 2x4s, rope, thick cardboard tubing, etc... There is never ANY use for a tip in these competitions so the majority of blades are squared off at the end. A camp chopper might be used to pull double duty(utility/chopping) and therefor might need a tip. Other than that there are specific criteria fo the choppers used in Bladesports. 15in overall length and 10in blade. Watch some bladesports competitions on youtube and you'll understand.
I use my comp knife as a camp knife, do I recommend this to customers who buy a true comp knife? no I don't. But so far I haven't had any trouble with mine. Not having a tip/point on my knife doesn't bother me because I don't go with just one. I have a belt knife and a folder that both have points when I'm in the woods.
Exactly. That's my understanding as well. My only problem is that I don't know if I can bring myself to drop out on a big slab of m4. There so expensive, I'd be afraid I'd screw it up. I guess at some point u just gotta shit or get off the pot...
It is not necessary to start with M4. In fact, I don't recommend starting with it. Most likely you will go through several designs, blade and handle, before you settle on a design. M4 is expensive, and hard to work. There are advantages to it. It holds an edge well. It is reasonably tough, tough enough for what we do. It doesn't require re-sharpening after every competition, usually a stropping is all that is needed, if that. We can run it at a higher Rc, mine comp knives are 60-62 HRc. And most importantly, it is readily available. The biggest advantage to me is how long I can use it for competitions before I have re-sharpened it to the point that the edge is too thick for my liking. The longest run I've had so far is 3 years on one knife, that was practice and comps. The edge thickness was still decent, but I was to the point of worrying about failure after that long and that gets in your head. And I just wanted a new to play with
I'll get into newer steels later, if interested.
So do you think 52100 would be too inferior to m4? I see that Jose Diaz(president of bladesports) makes a good amount of his choppers out of 52100. If that steel is comparable to m4 then I'd rather use it since its about half the price.
As stated above there are advantages to M4, for some. I'll use 5160, because I have more experience with it. When I was using 5160 I had to re-sharpen it after every competition, it would no longer shave hair in the more used spots and wouldn't slice newsprint cleanly. At the time, I didn't mind this because I was new and was developing my knife design, I changed knives so often then that I couldn't have afforded M4. With 5160 and the stage I was at with BladeSports, I changed knife design before I "wore" the knife out by re-sharpening. Once I got closer to the design I wanted and worked for me I changed to M4 and haven't really looked back. With M4 I don't have to re-sharpen after every cut, I just hone. So my knife lasts a longer before having to make a new one. I can also grind it thinner and run it harder, so that helps too. 52100 is a good medium ground between these two points, once again, this is not from personal experience. It is knowledge I've gained from other competitors.
Wow, thanks for all the great info gents. I think I might have come to a decision in regards to what I'm gonna use for the steel on my first competition-style(probably won't compete for a while)knife. The info gleamed in this thread really helped. I think I'll use 52100 for my first blade and build technique/skill with it and if I decide I want to compete down the road I will buy a slab of M4 and make another one. This initial blade will give me time to get familiar with the blade design and refine it for a M4(or other expensive super steel) knife later on.
In terms of affordable steels like 52100, do you guys think there would be any better options for my first chopper?
Also, the only thing I haven't been able to figure out yet is the blade geometry on these things. I've looked for a bladesports forum and done "bladesports knives" searches on google and haven't been able to dig up much. Anyone know where I could find some more technical specs on these blades?
Again, thanks for all the great insight folks, I really appreciate it.
I don't think you'll go wrong with 52100. If you don't have the mean to heat treat it yourself, I highly recommend Peter's Heat Treat. Tell Brad that the knife is for a comp knife. Dan and Jose have worked with him a lot on the heat treat for 52100 for BladeSports.
I touched on the blade geometry earlier as far as primary grind. Full flat and adjust to weight with saber grind if you wish, or up the stock thickness. I wish I could give you angles but I don't know. I recommend grinding the edge down to ~0.018" before sharpening. I believe the Rc that Dan and Jose use for 52100 is 58-60 HRc.
I hope this helps and feel free to hit me up at anytime with more questions.
bigdknives@gmail.com
Ya'll have a good night,
Donavon
