Strap Cutters/cutting Machines

[Nat1]

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,

[gringobill]

Are you using a big table to roll sides out on to cut them? I find that if you have a big surface to work on it will make the whole process a lot easier.

It helps to clamp the starting end down to the work surface with a spring clamp when using a draw gauge. If you do that you should be able to start a cut on thicker leather with the draw knife. I believe if you can pull the leather through the draw gauge rather than pulling the draw gauge through the leather it will help keep your cut straight. I start with the edge of the side hanging slightly off the edge of the table, I'm right handed, I pull the strap I'm cutting with my left hand while holding the draw gauge in my right and walk backwards as I cut. Being able to cut straight consistantly with a draw gauge is an acquired skill that takes practice to get good at like so many other skills used in this craft.

As far as truing up a strap with a crooked edge after it has been cut it can be done with a bench mounted pull through cutter but you've got to have one straight edge for it to work right. You're going to need that before you use your draw gauge anyway. You can cut that with a round knife or a sharp hand held trim knife. Once again, having really sharp knives is the key to sucess in all cutting.

I don't think an Aussie Strander will work for you cutting the heavier leather, particularly the veg tan. I believe they work best on thinner more pliable leather. The disposable blades in them flex too much for the heavy stuff. plus about 1/2" is the max you can cut with one.. If you have veg tan split down pretty thin It might work.

If you're cutting strips for sandals they're probably not real wide, l'm guessing they might be 1/2' to 1"? Seems like those narrower strips are easier to cut with a draw gauge than wider straps like 1 1/4" to 2"

You touched on one key to success using any cutter, having the blade as sharp as is possible and taking the blade out and stropping it pretty often.

A plough gauge does a better job on wider strips than a draw gauge. You are pushing the blade through the leather rather than pulling and it not only has the stop for the width but also has the adjustable roller on the top which holds the strap being cut down against the beam giving you more control. the strap can't ride up on the blade like on a draw gauge. Plough gauges are not too easy to come by and they are pretty pricey but IMHO worth it. The Dixon company in England is the only company I know of that still makes them, there may be others but I'm not aware of them. Bruce Johnson on this site usually has some for sale and if you get

one from him it will be in good shape and ready to go. You can expect to spend between $350 and $400 for one which is a lot less than the "thousands," you mentioned.

Good luck!

Bill

[Art]

If you buy whole sides from Weaver, they will cut it for a standard fee. This can work well cost wise as you open the box and you have product ready to roll. Eventually you end up getting a strap cutter for about $2K. After you make the first pass on it, you will kick yourself around the shop for an hour wondering why you waited.

Art

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,

[Nat1]

Are you using a big table to roll sides out on to cut them? I find that if you have a big surface to work on it will make the whole process a lot easier.

It helps to clamp the starting end down to the work surface with a spring clamp when using a draw gauge. If you do that you should be able to start a cut on thicker leather with the draw knife. I believe if you can pull the leather through the draw gauge rather than pulling the draw gauge through the leather it will help keep your cut straight. I start with the edge of the side hanging slightly off the edge of the table, I'm right handed, I pull the strap I'm cutting with my left hand while holding the draw gauge in my right and walk backwards as I cut. Being able to cut straight consistantly with a draw gauge is an acquired skill that takes practice to get good at like so many other skills used in this craft.

As far as truing up a strap with a crooked edge after it has been cut it can be done with a bench mounted pull through cutter but you've got to have one straight edge for it to work right. You're going to need that before you use your draw gauge anyway. You can cut that with a round knife or a sharp hand held trim knife. Once again, having really sharp knives is the key to sucess in all cutting.

I don't think an Aussie Strander will work for you cutting the heavier leather, particularly the veg tan. I believe they work best on thinner more pliable leather. The disposable blades in them flex too much for the heavy stuff. plus about 1/2" is the max you can cut with one.. If you have veg tan split down pretty thin It might work.

If you're cutting strips for sandals they're probably not real wide, l'm guessing they might be 1/2' to 1"? Seems like those narrower strips are easier to cut with a draw gauge than wider straps like 1 1/4" to 2"

You touched on one key to success using any cutter, having the blade as sharp as is possible and taking the blade out and stropping it pretty often.

A plough gauge does a better job on wider strips than a draw gauge. You are pushing the blade through the leather rather than pulling and it not only has the stop for the width but also has the adjustable roller on the top which holds the strap being cut down against the beam giving you more control. the strap can't ride up on the blade like on a draw gauge. Plough gauges are not too easy to come by and they are pretty pricey but IMHO worth it. The Dixon company in England is the only company I know of that still makes them, there may be others but I'm not aware of them. Bruce Johnson on this site usually has some for sale and if you get

one from him it will be in good shape and ready to go. You can expect to spend between $350 and $400 for one which is a lot less than the "thousands," you mentioned.

Good luck!

Bill

Thanks for the advice, Bill. These are all good tips. I wasn't clamping the work, and my work surface is limited--but I won't get into that-- and I will try pulling the leather rather than the tool. The Aussie Strander I wanted to try with the softer oil-tan leather, which I'm finding more difficult with the draw gauge than the stiffer veg tan.

Yes, about sharp knives... I've known this and keep working on it. I do eventually get things sharp, but I wish I was quicker at it. I've been experimenting with flat grind, or scandy grind recently. Any posts on this topic?

Nathan

[Nat1]

If you buy whole sides from Weaver, they will cut it for a standard fee. This can work well cost wise as you open the box and you have product ready to roll. Eventually you end up getting a strap cutter for about $2K. After you make the first pass on it, you will kick yourself around the shop for an hour wondering why you waited.

Art

Thanks for the ideas, Art. Never crossed my mind to buy straps already cut! To be honest, I think I'm too stubborn to do that, as I like this work because of all the skills I learn as I go. Having said that, business sense is a skill! And if the goal is to produce... but that isn't my only goal.

What is the name of the strap cutter for $2000? I'm not ready to go that route, unless my business goes off the charts (which for sandals in Canada, won't likely happen at least for a few months from now!).

I see you make knives... I was just asking Bill about the flat grind. Do you have any experience with that? I'm very interested in this, as I can see the results are phenomenal when I pull it off, but it seems very tricky to do, especially without ruining blades.

Nathan

[Art]

Hi Nathan,

The AK-20 strap cutter by Cobra is based on Randall designs of old and does a pretty good job, I have one and the only problem is it is HEAVY.

As to knife grinds, a full flat is not something I would wish on a customer. They are not going to sharpen it right, and if they did, they would pretty much eat up the blade with grinding over time as you have to sharpen (grind) the full width of the blade. Assuming you use a 20 degree per side bevel, there is not much in the way of steel behind the edge, and that is not a good thing. With the scandi, that is just a flat that starts further down the blade sides and can suffer some of the same problems. I recommend secondary bevels on these types of blades. With the kind of sharpness required for leatherwork, the secondary bevel is almost a fact of life, the bevels are 15-20 degrees on a side and require a high polish that you get from fine stoning, few have the patience to work the full dimension of a head knife up to xxfine. A good skiving knife might be the exception, it is a one sided scandi of sorts, sharpened along the whole bevel.

However, don't let me put off of the full flat, I recommend a large platen belt grinder like the 6x48 and a lot of belts.

Art

[Nat1]

Hi Nathan,

The AK-20 strap cutter by Cobra is based on Randall designs of old and does a pretty good job, I have one and the only problem is it is HEAVY.

As to knife grinds, a full flat is not something I would wish on a customer. They are not going to sharpen it right, and if they did, they would pretty much eat up the blade with grinding over time as you have to sharpen (grind) the full width of the blade. Assuming you use a 20 degree per side bevel, there is not much in the way of steel behind the edge, and that is not a good thing. With the scandi, that is just a flat that starts further down the blade sides and can suffer some of the same problems. I recommend secondary bevels on these types of blades. With the kind of sharpness required for leatherwork, the secondary bevel is almost a fact of life, the bevels are 15-20 degrees on a side and require a high polish that you get from fine stoning, few have the patience to work the full dimension of a head knife up to xxfine. A good skiving knife might be the exception, it is a one sided scandi of sorts, sharpened along the whole bevel.

However, don't let me put off of the full flat, I recommend a large platen belt grinder like the 6x48 and a lot of belts.

Art

Thanks for the info, Art. I'll keep experimenting with the styles and combos.

Nathan

[bruce johnson]

Just another affirmation of Art's statement about a flat grind. That is one of the biggest problems I see with people and new round knives. They get a knife and think thinner is better. There is a difference between taking a shoulder down on an edge and doing a flat grind. Terry Knipscheild and I talked about this a couple weeks ago. These are not straight razors. I have seen the video of the guy who can shave with a good edge on an axe, but that you don't chop wood with a razor.The Moran edge or Convex edge is not a new concept. Some people do it with slack belts and others with a stones and straighter secondary bevels. Stropping on softer leather will help make a slightly convex edge too. In any case there needs to be some steel backing up that edge to stabilize it. A flat edge all the way out will chip or roll. If it rolls many new people to round knives don't understand what is going on and will think it is dull. Also not stropping a stoned knife enough to take the foil/wire edge off will seem dull when it is about 10 strokes from being great.

[Nat1]

Just another affirmation of Art's statement about a flat grind. That is one of the biggest problems I see with people and new round knives. They get a knife and think thinner is better. There is a difference between taking a shoulder down on an edge and doing a flat grind. Terry Knipscheild and I talked about this a couple weeks ago. These are not straight razors. I have seen the video of the guy who can shave with a good edge on an axe, but that you don't chop wood with a razor.The Moran edge or Convex edge is not a new concept. Some people do it with slack belts and others with a stones and straighter secondary bevels. Stropping on softer leather will help make a slightly convex edge too. In any case there needs to be some steel backing up that edge to stabilize it. A flat edge all the way out will chip or roll. If it rolls many new people to round knives don't understand what is going on and will think it is dull. Also not stropping a stoned knife enough to take the foil/wire edge off will seem dull when it is about 10 strokes from being great.

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?

[bruce johnson]

Yes I have tried it on round knives and point knives. I figured a thinner blade with a razor edge would cut easier. It does for about a foot. I chipped out edges and rolled edges on some pretty good steel if I cut leather with any resistance to it. That was my experience. I do have a flat ground skiving knife from England. It is flat ground on one side. It is great for skiving soft chrome tan. That is the only thing I use it for. If you are doing a lot of chrome tan, I'd do it. It is not so bueno for vegtan.

I was taught to sharpen my knife at one angle on a stone or wet-dry, and then do a few passes at a higher angle to make a secondary bevel. It can be very slight and still back up that fine edge. Herb French has a handy little book on sharpening leather tools. You can probably still get it from Sheridan Leather Outfitters. A few years back somebody mentioned this link - Sharpening A Convex Edge here on the forum. Basically it is an infinite secondary bevel. This edge has been the best in my hands. Easy to do and way better cutting and edge life than anything I have done before. I don't have this belt lift - Belt Lift, but those who do like it. I do mine a bit different but get the same effect. There used ot be a youtube video on it, but it was taken down.

To reiterate, this is not the same as having a blade with a lot of shoulder. This is at the very edge. The blade still needs to bevel some to the edge. I use stones to take down shoulders and profile. I use a slack belt to do the final edges.

[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,