Design critique / WIP Chopper and NYS boot

[timos-]

Hello all,

While I am waiting for my first batch of blades to get back from HT I figured it would be fun to post a couple projects Ive got going on.

Id like to build a 14" chopper. Ive never really used a knife of this size much so thought Id post some ideas and get some feedback I think Im on the right path here but would appreciate some tough criticism.

Stock I am using is 1095 steel 5/32 x 2 x close to 14 inches.

What do you guys/gals think of this?

My other project is one I started a few months ago before I built my belt grinder. I have 4 New York Special Style boot daggers i started using a hacksaw/files/bench grinder.

Now that I have the belt grinder Ive been using the 2" wheel t0 refine the profiles. I also started grinding the bevels on one of them.

Notice i cut the secondary bevel in before the primary one I do not know a good way to fix this but I will try to even them up.
Tomorrow I will post some grinding in action. Maybe finish all 4 bevels and get a bit closer to a final design on the chopper.

 

[timos-]

Ok Ive finished the bevels with the 80 grit Blaze belt. Moved on to my Gator 300. Not too happy with the results. The texture of Gator belts kind of kill the sensitivity i need on a blade this small. See for yourself below.

I think the photo is losing alot of detail...the lines were much more crisp before the gator.
Now adding some paint back to the edge to keep an eye on it.

This is the way Ive been keeping my grinder setup. I like the angle so I can get in close. I am Loving the 36" radius platen. It is probably an odd piece to start with but Nathan the machinist makes such awesome stuff I wanted to get one. Plus the idea of mimicking an old school large grinding stone is awesome. More on the platen later.

Switching to a Norax x45. I am hoping to get my sensitivity back so I can handle these four bevels better.

I removed a bit too much material with the gator and now i am fighting between removing scratches and keeping all lines consistent. My flat edges have now shrunk from about .04 to .01 in most spots.

Checking the edges I notice this:

I did not take the pic at a perfect angle but what I am seeing is although the edge is still centered the blade is now warped way to one side. I have no idea if that is gonna be correctable or not. I am not planning to do any heat treating any time soon. So I am guessing straightening that is a job for the Heat Treater.

Maybe I will get around to that CHopper a little later ...I am starting to hate the handle layout though.

 

[Grayzer86]

I have never used a radius platen, but it seems like it would be more beneficial to have it carter out from the wheels. I would think this would allow more control and eliminate the possibility of wandering up or down near the slack belt section and having an issue with convexing the grind slightly. Like I said I have not used one of these plate a but it seems to make sense in my mind anyway. By the way, I really like the looks of that big chopper

 

[timos-]

Grayzer you are right about the radius platen being out further. The slack belt areas are a danger zone when grinding bevels. I have accidentally hit those spots a couple times. One advantage to having a minimum of belt contacting the platen is it doesn not get too hot.

I came up with a different design for the Chopper I think I am gonna go with. I think it would be more effective. Just wish I had another section of 2" wide 1095 to do both.

 

[Grayzer86]

I would say that new design may be a bit more effective at chopping, but personally I think it will be a lot less useful for anything else. Actually after looking at both, I still feel that the first design may chop just as good or better than the second. I do like both though. If it was me I would make both and test them head to head haha.

 

[redd1981]

I love that first design.

 

[quint]

Designs are looking pretty good. I wanna comment on the warped blade. You dont want any warps going into HT. If there are any uneven grinds going in, they will be exasperated during the HT and will be even harder to correct. I have found thru my limited experience that even grinds (as even as humanly possible) and normalizations are key to reducing or eliminating warps during HT and more accurately the quench at the end.

If I was paying for HT I would chack that blade up as a learning experience and give it another go. Right now you would only be out a few dollars on a little bit of steel and any belts or other materials used to get thus far.

 

[timos-]

Thanks for the info Quint, Brad at Peters heat treat said he can straighten from end to end but not any warp along the edges. If I can get the cost per blade down enough I guess Id send it out but you are probably right.


As far as the chopper goes I will post the refined design in a hard maple handle mock up... with some rough bevels later in the week.

Now I am itching to use some super steel type stuff. Does anyone think the K390 or M4 steels would lend itself to a design like that chopper on the top?

 

[meanwhile]

Speaking as a user who used to live recurves and then had to sharpen one, I'd be interested in seeing the results of a comparison if you ever build a version of the knife with a straight edge.

(Beautiful proportions on the v.1 btw - I'm guessing it follows Golden Ratio??)

 

[tryppyr]

I'm still trying to wrap my brain around a boot dagger.

I like the grind a bit more than I like the handle shape.

 

[timos-]

Ive spent a couple hours now trying to grind that recurve and its a bear.
Meanwhile: Im not sure about the golden ratio, for sure I do like to split things somewhere between the first and second third of a length whenever possible. Its actually pretty amazing how well knives, tools etc lend themselves to this ratio.

tryppyr: Thanks for the comments but what handle shape are you referring to? the dagger or one of the choppers?
Btw I enjoy following your WIP threads. I think you should make a couple friction folders with that damascus bar you have!

I will attempt to finish up the grinding today and post the results.

 

[Stark Knives]

I prefer the first design...

 

[timos-]

yeahhh the classic design , I kinda wish i did that one. Ill definitely get some steel to try it. Question is what steel? Ill have to research some good steels for choppers.

 

[Willie71]

@ meanwhile, I am assuming the golden ratio you mention is the Fibonacci sequence based ratio. Anything based on that design is visually pleasing. I draw my designs, and take pictures with the framing based on that ratio. I too like v1 better. The second looks too video gameish for my tastes, but the nice thing is you can build what you like regardless of what others like.

 

[Willie71]

Some of the other members have mentioned S7 for choppers. Very durable, just won't hold the edge as well as some other steels from what they are saying. Haven't used it myself though. With the warp, try clamping it between two 1/4 or 3/8 pieces of steel and bake at 400f for 1h. See if it straightens out.

 

[james terrio]

yeahhh the classic design , I kinda wish i did that one. Ill definitely get some steel to try it. Question is what steel? Ill have to research some good steels for choppers.

Don't get too hung up on trying a bunch of different steels, it will add a lot of cost - especially if you're sending them out for HT. Concentrate on your geometries first. 1095 and 1084 with pro-level HT work very well for knives both large and small, and they're both affordable. Once you get a few under your belt you can start refining your steel choices for even higher edge retention, corrosion-resistance, etc. CPM-3V, Elmax and CPM-M4 are all great "super steel" choices... but they're pricy.

Take a look at some cutting competition videos and knives if you want to learn about serious choppers. One of the first things you'll notice is that very few of them really have a tip or even much of a belly; more of a wharncliffe style pattern. Might as well keep as much weight as possible out towards the tip for greater power and leverage, especially if you're handicapping the knife by having "only" a 7 or 8" blade. If you want maximum chopping ability, you really need to reach out with a 9 or 10" blade... the difference in tip speed and leverage is pretty remarkable.

I do like your first "chopper" design quite a bit for a general camp knife... in fact I'm working on one very similar... have you been sneaking peeks into my notebook?!? Just kidding of course... it's a good basic pattern that's been around a very long time

 

[Willie71]

Anyone with more experience please chime in. With small light kindling hatchets, I often drilled the end of the handle and pressed in a piece of steel and swung a bit farther up the handle. The momentum transfers through the fulcrum (your grip) and results in more energy at the blade. I am assuming an extra inch on the handle with weight in it would have the same effect.

 

[timos-]

WOw , finally got around to profiling the original knife drawing at top of this thread!

Its in .26 thick 5160. Will be overbuilt for sure. Im also thinking of making another in a 3/32 pc of 52100 i got laying around, maybe even 2. Thoughts?

 

[timos-]

Well Finally am almost finished with Version 1 of the Vendetta Model. My WIP is posted on my website although its more of a pictorial.