Cutting A Tapered Strap

[soloptik]

After extensive use of the search button, I'm at a bit of a loss. I'm a beginner here, mostly making watch straps. My question is how to produce a strap that is anything other than a straight piece with a punched end. For example:

pilot strap

Do you think this was cut with a clicker die? How to make a symmetrical cut on both sides of the strap? Or am I making this more complicated, maybe it's just a pattern traced on to the leather, and cut very carefully with a round knife?

Any help would be hugely appreciated!

[wildrose]

Using a strap end cutter would be the solution. I have an English Bridle strap end cutter and it'd work for something like that. You can get them in different sizes, and cut off only as much as you want.

[soloptik]

Hi, thanks so much for the reply. The part I'm having trouble with isn't the tip though. I've got an english point strap end punch which works well. It's more the contour down the length of the strap. In the photo you can see how it starts off at something like 24mm at the lugs, then midway it tapers down to something like 20mm. I'm wondering if that's done by hand with a knife, and if it's something you would do before or after gluing and folding the strap, or done some other way altogether. Thanks!

Using a strap end cutter would be the solution. I have an English Bridle strap end cutter and it'd work for something like that. You can get them in different sizes, and cut off only as much as you want.

[wildrose]

ahhhh, I understand now - sorry about that. I've had that same issue on sword scabbards, actually. I guess it's easier to do on big items though.

[TwinOaks]

Determine the width you want for the tapered section, subtract from the base width. Divide that number by two and that's the amount you cut off each side. For the transition, mark a point from one end of the strap as the beginning of the transition, and use a repeatable pattern- diameter of a punch, section of a French curve, stencil, etc. Once you've marked it, cut it out. If you have access to to a clicker, it's even easier to do ....once you've designed your die. The clicker is the way to go if you will be producing a large number of the same pattern, and you can make a hammer die (cutter) if you can't afford a press set up.

[Frogman Watch Straps]

Make yourself a template first and then you can use that as a guide to cut the folded leather. Works like a charm. Tapered straps are a pain in the butt....however they look really nice!

[gringobill]

One way to make yourself a template is to take a piece of graph paper, figure out how wide you want your finished strap to be, draw those demsions on the graph paper then and fold it in half and draw your design along the outside edge (not where it's folded,) cut it out with scissors and then either make a better template or carefully use the graph paper. If you going to use it more than once it'll make your life easier if you make the finished product out of heavy paper, poster board, cardboard, manila folders are pretty good. Something that's stiff enough to trace around without it folding up on you.

[rawhide1]

Here's how I do mine. Say I have a 1" strap that's 2foot long and I want to taper it down to 3/4" six inchs from the end. I take a pair of dividers and set them at 1/8" and then lightly mark my strap on both sides from the six inch mark on down to the end of the strap. I will then take a English end punch ( which ever size works best) and place the point on the edge of my strap at the 6" mark and the curve of the punch on my scribed line. I will wack this with a maul I then take my round knife and finish the long straight cut. This gives a nice curve at the transition and the round knife will make a nice straight cut.

I'm not saying this the best or only way but it works great for me.

Best of luck, Mike

[threepets]

Thankyou rawhide1, I am now able to taper my straps satisfactorily. My first attempt ..not so hot , but I see with practice this will give me the strap taper I am looking for .

[Rahere]

I've just tried using a digital caliper as a scriber, I'm a fan! A spline curve's defined by 4 points, start and end are known, you set your curve there and mark the intercepts at two arbitrary points, project the distances (lock the caliper) to the other side (I hold it against a thick steel straitedge both in setting and transcribing), flip the curve and match the points. It may help to apply masking tape to the curve to register the points on there too.

[Danne]

I make a template in a cad software (but graph paper work fine of course) then I glue it to thicker card paper and cut it out.

It requires some practice to cut the leather with precision. But two things that help is to start with a very shallow cut, and put a little extra pressure on the end of your template/your cut.

 

Edited June 30, 2021 by Danne

[Rahere]

13 hours ago, Danne said:

I make a template in a cad software (but graph paper work fine of course) then I glue it to thicker card paper and cut it out.

It requires some practice to cut the leather with precision. But two things that help is to start with a very shallow cut, and put a little extra pressure on the end of your template/your cut.

 

You might find a silver pen would help transfering the pattern rather than cutting directly from the pattern, it allows you to see what's going on without the paper getting in the way. I also rework my patterns and laminate the cutting version in plastic, if there's any possibility I'll be doing alterations, so process stages are preserved.

[Dwight]

Some simple templates . . . if I envision this correctly . . . it is wider at one end (or both ends) than in the middle . . . those templates are easily made and work wonderfully.

Take a piece of 1/16 inch aluminum bar that is 1 inch wide . . . and at least 3 inches longer than the narrow part of the strap.  Then file or grind down the middle area such as in the little drawing I have included.  

You then clamp it at both ends on the edge of your work bench . . . with the strap underneath it . . . put your thumb on the back side of it in the middle . . . and use a very sharp razor knife to make the cutout.  In this case I believe we were going from 24 mm to 20 mm . . . so the area ground down in the template needs to be 2 mm.  Once you have cut the one side . . . flip it over and do the same for the other side.  

If you take your time and make your aluminum template well . . . it will serve you for the rest of your life . . . barring some unforseen accident.

May God bless,

Dwight

[Danne]

2 hours ago, Rahere said:

You might find a silver pen would help transfering the pattern rather than cutting directly from the pattern, it allows you to see what's going on without the paper getting in the way. I also rework my patterns and laminate the cutting version in plastic, if there's any possibility I'll be doing alterations, so process stages are preserved.

This work quite good for me, but a silver pen is certainly a good idea that I will use for bund straps like this one, if it's a soft or a leather that doesn't work to scribe well. For stiffer veg tan a thin round awl work good. But chevre Sully is a good example. Can't scribe, really hard to cut along a template without anything moving (I have to constantly move my fingers to put pressure on the correct places of the template) And use a fine pen and paint on the flesh side isn't really a good option for me either, because I find it hard to free hand cut from the flesh side, because I can't really make a primary cut and follow it for multiple cuts. Thanks for the tip. A silver pen is on the list.

 

[Danne]

Made a template for people who want to try to glue on card paper and use as templates.

Standard size 115/75. 18-16, 20-18, 22-20 

When you print it and measure to the fold line you will see that it's 1mm too short, the template is made for 1mm leather, and when folded it compensates for the fold. (So not a error in the drawing)

I choose to not use a curve for the taper, because it's such a small taper it will both look curved and be curved when sanded. And it makes it easy to cut out templates after glued to card paper, because you can use a ruler for everything except the "point" (tip: Cut the template point in multiple cuts, and start with a very shallow cut) you can do the same on leather, or scribe along the template, silver pen, or cut along the edges and finish with "stabbing" around the tip with a skiving knife, and sand it into shape. 

 

I haven't tried printing the letter size (since I have an A4-printer) but if something is wrong with dimensions notify me so I can solve it.

Instruction.pdf Templates_A4.pdf Templates_letter.pdf

 

Edited July 1, 2021 by Danne