Strap Cutters/cutting Machines

[Art]

Hi Nat,

I have skiving knives that are scandi profiles, a scandi is a flat grind that only goes up the blade some distance where the sides flatten out. I have a few skiving knives that are sharpened on both sides but most are one side only. I generally skive with the bevel down. I find bevels on both sides are better for veg tan, and the singles I use for chrome. Don't ask the theory of this, it is just practice.

A hollow grind is one that is obtained on a wheel, the blade will have a concave profile that matches the convex profile of the wheel. A convex edge profile is obtained on a slack belt. There are several ways to accomplish this.

As I have said before, I put a secondary edge on most of these profiles.

Stropping more than frequently is a necessity on any of these low angle edges as there is not a lot of metal up there on the bleeding edge and a micro-fraction of the edge is always rolling.

Art

The first thing I'd like to clarify is I'm not attempting the flat grind with my round knife, since two of you have referred to that. I am experimenting with some old straight blade leather utility knives. I'm not sure if that makes any difference anyhow, as I am more interested in the concepts, and where it can apply effectively. I do understand the basic concepts of thickness and angle of bevel for different tasks , so I wasn't planning to go chopping wood rounds with a flat ground leather knife... I am new to this flat grind subject, however, so I don't understand all the in's and out's, and I certainly don't have the experience to modify a knife properly myself yet.

I don't know what a Moran or Convex edge is. I've hear of hollow ground also, but not sure I understand that exactly. Do any of you have some sites or you tube videos that would be helpful or instructional on this topic?

I have met two leather workers now who use the flat grind (or scandy, is there a difference?): One was a moccasin maker who uses this knife strictly for skiving, and he is very efficient with it. The other man's knife I got to try, and it worked very effectively, yet there was still steel--some thickness--left, it was not a razor blade. We didn't have enough time together for me to get all the details.

Let me ask it this way:

Do any of you own any knives ground this way, and if so, what is your experience, and which tasks do you prefer them for?

[Nat1]

Hello Bruce and Art,

I thank you both for the information you've shared, and have been doing more reading and watching online. I'm definitely going to explore the convex edge, and amongst many others, I found a simple and straight forward approach to this on you tube, by knife maker J. Neilson.:

What you both said about using a scandi for skiving chrome makes sense, since the moccasin maker I mentioned uses it for this purpose. My step-dad recently gave me what looks like a traditional japanese knife that looks to me like a scandi profile, on one side only. I'll try to get around to uploading a photo of this. Is it easy to upload pics on this site?

Thanks again,

Happy skiving,

Nathan

Hi Nat,

I have skiving knives that are scandi profiles, a scandi is a flat grind that only goes up the blade some distance where the sides flatten out. I have a few skiving knives that are sharpened on both sides but most are one side only. I generally skive with the bevel down. I find bevels on both sides are better for veg tan, and the singles I use for chrome. Don't ask the theory of this, it is just practice.

A hollow grind is one that is obtained on a wheel, the blade will have a concave profile that matches the convex profile of the wheel. A convex edge profile is obtained on a slack belt. There are several ways to accomplish this.

As I have said before, I put a secondary edge on most of these profiles.

Stropping more than frequently is a necessity on any of these low angle edges as there is not a lot of metal up there on the bleeding edge and a micro-fraction of the edge is always rolling.

Art

[raysouth]

I am by no means a production expert but I do cut a good number of straps with the Tippmann embosser which has a cutting setup included. No idea if this would work for you but I cut some decent straps, using the guides.

God Bless.

Hello!

I've read some of the threads regarding lace cutters and Aussie strand cutter, which looks wonderful for the stiff and thin leather demonstrated on the bullwhip video. I'm not sure how well it would work for my purposes.

I'm using either veg tan 5-6oz, or a chrome tan or oil tan 5-6 oz, or 2-3mm, and the straps are generally between 9 -12mm (or 0.35 - 0.47 inches) in width. I manage reasonably well with an old all-metal draw gauge, but inevitably it veers off course once or twice along the way and creates lumps or narrow stretches. It works better for the veg tan than the softer leather. Of course the sharper the blade, the better it works. What is a good way to even out the width of such a strap afterwards? Also, it is slow starting a cut with the draw gauge: is there a trick? I usually end up starting it with a knife, but all this is time consuming, as I am producing a fair quantity on a regular basis for sandals. Wondering if there is a more efficient tool, without spending in the thousands of $. Perhaps it is only a matter of technique, or my tool is not quite right.

I'd love to hear some ideas on this. If this has been posted elsewhere, I apologize, but the list is intimidating, and I'm not coming up with much with the "search" option (either nothing, or too much non-relevant material). While I'm at it, what does "manage topic poll" mean?

thanks,