Laser etching carve design

[Bert03241]

Has anyone tried etching a design on leather then carving it out with a swivel knife.

[Bert03241]

[Gulrok]

On 6/2/2022 at 3:12 PM, Bert03241 said:

Has anyone tried etching a design on leather then carving it out with a swivel knife.

Learning LEATHER TOOLING With Help From LASER ENGRAVER? - YouTube

I believe this is what you're looking for. 

[Bert03241]

Thanks Gulrok, that's exactly what I was looking for. My main concern was if there's any char in the lines that would dull my swivel knife.

[Ard Righ Art]

Yes. I tried lots of different ways over the years to transfer patterns to leather more efficiently. Running a laser with as low power as you can use to still mark the leather is definitely the best. Even then, as you will see if you are trying to score a line for bending, the laser cuts the outermost layer of the leather, which you may not want for folding.

In the video above, the guy thinks he should lose focus for a thicker line. I understand his thinking, but he was hypothesizing without experience. Thinner is definitely better. You can easily run the knife along the markings. This makes a different sort of cut than just using the laser, because of the angle of the blade.

But, you may find that experimenting with replacing the swivel with the laser is also fun and has a few benefits: It obviously allows greater production in less time. It allows more regularity - though there are pros and cons to that, but by the time you bevel you will get back some or a lot of the "human touch" - and can allow you to really test your ability to tool a *small* pattern. You can also go large and find yourself biting off a lot more pattern than you thought you were going to chew.

Some tips I have picked up along the way, mostly through the school of hard knocks.

Wet the leather first, not necessarily fully cased but enough to cut back on the burn. If you are going to have a deep cut edge or holes on a thicker piece, you may want to tape there with really low stick tape, though that has its own issues.

Test cut every time. Try various power and speed combinations for both the pattern depth and cutting through. The laser will vary in power with lens cleanness, tube age, focus, etc. Also, you'll want to try to have the same degree of wetness on your test piece, which ideally will come from the same leather you are using. The lasers I use go about bevel depth at 5-7%, and cut through 3/4 oz in the 20s, 8/9 in the 40s or 50s.

Cut the design first, then cut out the holes, then the edges. If you cut holes with the machine, you may find dye or stain bleeding through to the flesh side. If you use a liner, this is not a problem, but if it will not look good, punch by hand. I have not seen that it has caused any issues, but could argue that a line of burnt holes may be weaker than punched ones - don't put them too close together. It's also easy to put more holes than you needed, and therefore more stitching time than you needed, when you're designing. On the other hand, if you remember to mirror your hole-line and cut out the insides of the project, you can really save time and body pain, and have it all line up the first time.

Rather than score fold lines or punch lines with the laser, make a tiny dot at the ends and use a straight edge to avoid finding that you have cut the epidermis and weakened a fold. Lasers can't supplant everything and by hand is still faster for some steps.

Strike to the depth of the cut. Maybe use a patterned bevel and a heavier hand or mallet.

The edge will be straight, like this: |/ rather than a V, if you don't use a swivel. You can dress it with a ball end or other tool to get some of the angle back. You might be in the habit of doing that anyway.

You can use the burn as part of your pattern, it gives a nice contrast to it without staining/highlighting the whole piece.

Once you've taken the time to set up a pattern and item, it's done. Sort of like making your own kits, with the caveat that you have to make the test cuts every time.

---

I started my quest after speaking to a guy at a fair who "used to do everything by hand like you, but ... could only make [X] grand per year, so [he] started embossing everything with instead." I ceded the production time issue, especially as I am not able to do this full time at the moment, but really didn't want to quit tooling. I know some folks don't see the use of tech as art, but I think it can be, or we can resolve to meld them and do our best with whatever technique we light upon. I also have items that are completely traditional and always will be, and have a higher value because of it. For my business purposes, I am finding it takes both kinds to make it worthwhile at the moment. And I have fun either way.

---

The pictures below are a journal cover cut by hand with an inset of one cut by laser, a lased barrette, and a small necklace. The first one is not a great example in some ways because the staining is so different, but it still shows some of the differences. The barrette was stained lightly, I don't have a handy pic of one natural. The last is just a small size pic either 20 or 24mm. That is not too small to do by hand, but it is more consistent to make a few without waste of time or leather with the laser.

 

 

[Bert03241]

Wow thanks for that in depth tutorial. I didn't understand it all , but got th jest of it. Now I guess I have to print this out and try some laser carving.

[KYCat]

On 7/19/2022 at 1:17 AM, Ard Righ Art said:

Yes. I tried lots of different ways over the years to transfer patterns to leather more efficiently. Running a laser with as low power as you can use to still mark the leather is definitely the best. Even then, as you will see if you are trying to score a line for bending, the laser cuts the outermost layer of the leather, which you may not want for folding.

In the video above, the guy thinks he should lose focus for a thicker line. I understand his thinking, but he was hypothesizing without experience. Thinner is definitely better. You can easily run the knife along the markings. This makes a different sort of cut than just using the laser, because of the angle of the blade.

But, you may find that experimenting with replacing the swivel with the laser is also fun and has a few benefits: It obviously allows greater production in less time. It allows more regularity - though there are pros and cons to that, but by the time you bevel you will get back some or a lot of the "human touch" - and can allow you to really test your ability to tool a *small* pattern. You can also go large and find yourself biting off a lot more pattern than you thought you were going to chew.

Some tips I have picked up along the way, mostly through the school of hard knocks.

Wet the leather first, not necessarily fully cased but enough to cut back on the burn. If you are going to have a deep cut edge or holes on a thicker piece, you may want to tape there with really low stick tape, though that has its own issues.

Test cut every time. Try various power and speed combinations for both the pattern depth and cutting through. The laser will vary in power with lens cleanness, tube age, focus, etc. Also, you'll want to try to have the same degree of wetness on your test piece, which ideally will come from the same leather you are using. The lasers I use go about bevel depth at 5-7%, and cut through 3/4 oz in the 20s, 8/9 in the 40s or 50s.

Cut the design first, then cut out the holes, then the edges. If you cut holes with the machine, you may find dye or stain bleeding through to the flesh side. If you use a liner, this is not a problem, but if it will not look good, punch by hand. I have not seen that it has caused any issues, but could argue that a line of burnt holes may be weaker than punched ones - don't put them too close together. It's also easy to put more holes than you needed, and therefore more stitching time than you needed, when you're designing. On the other hand, if you remember to mirror your hole-line and cut out the insides of the project, you can really save time and body pain, and have it all line up the first time.

Rather than score fold lines or punch lines with the laser, make a tiny dot at the ends and use a straight edge to avoid finding that you have cut the epidermis and weakened a fold. Lasers can't supplant everything and by hand is still faster for some steps.

Strike to the depth of the cut. Maybe use a patterned bevel and a heavier hand or mallet.

The edge will be straight, like this: |/ rather than a V, if you don't use a swivel. You can dress it with a ball end or other tool to get some of the angle back. You might be in the habit of doing that anyway.

You can use the burn as part of your pattern, it gives a nice contrast to it without staining/highlighting the whole piece.

Once you've taken the time to set up a pattern and item, it's done. Sort of like making your own kits, with the caveat that you have to make the test cuts every time.

---

I started my quest after speaking to a guy at a fair who "used to do everything by hand like you, but ... could only make [X] grand per year, so [he] started embossing everything with instead." I ceded the production time issue, especially as I am not able to do this full time at the moment, but really didn't want to quit tooling. I know some folks don't see the use of tech as art, but I think it can be, or we can resolve to meld them and do our best with whatever technique we light upon. I also have items that are completely traditional and always will be, and have a higher value because of it. For my business purposes, I am finding it takes both kinds to make it worthwhile at the moment. And I have fun either way.

---

The pictures below are a journal cover cut by hand with an inset of one cut by laser, a lased barrette, and a small necklace. The first one is not a great example in some ways because the staining is so different, but it still shows some of the differences. The barrette was stained lightly, I don't have a handy pic of one natural. The last is just a small size pic either 20 or 24mm. That is not too small to do by hand, but it is more consistent to make a few without waste of time or leather with the laser.

 

 

Thanks so much for the info--- I've been working with leather for a while but just got a 10W diode laser in November. Have been working in Lightburn figuring out 'stuff' and have finally gotten around to leather.

Would like to also incorporate the accuracy of the laser (read: straight lines :)) with tooling.

What thickness leather are you using?

Thanks for any tips!

[Ard Righ Art]

@KYCat  I am sorry, I haven't been actively checking my email used to register here. I guess I should change it.

If you're still interested, I use 3-4 oz for items like journal and flask covers and necklace inserts, and 8-10 oz for belts, straps, barrettes, and even bracelets (though I am thinking of making those less sturdy/thick in the future).

Slower speed makes a lower power burn through more. I am thinking about experimenting with whether faster speeds at higher power create less burning and how to measure this. I have opted for slower out of concern for the fact many of my patterns have a lot of twisting and turning on them, and high speed could result in jerking the laser head around more, and does create more over-travel as the laser changes direction. This is more important with raster images than vector cuts I think, but may still be a concern. With a program like lightburn, you can get a time estimate and discover that this speed induced over-travel can ADD time to a project as the laser travels farther on either side to change direction. But that's of topic...

Not all laser controllers measure the speed/power parameters the same way.  I have used full spectrum and glowforge, but it's been a while so I don't remember which is which, but some use speed as a percentage of full speed rather than a set distance per unit of time, and some use power as a unit rather than percentage. IIRC, full spectrum has a power option assignable to each color, and an overall percentage of power that is applied across the board, which can further reduce or fine tune your control output. Regardless, your two variables are speed and power, and you have to experiment around a bit initially, as well as from time to time as conditions, cleanliness, or other items change.

On my laser (130w gweicke) I tend to run 30 to 40 mm/s at the power percentages I mentioned above. I guess to consolidate,  5-7 percent for cutting the tooling pattern to about swivel knife depth, irrespective of thickness of leather. 20-25 percent to cut all the way through 3-4 oz, and 40-50 percent to cut through 8-9 oz leather, including holes for stitching. If you use a ruida and lightburn, you may want to experiment with the minimum power output setting to prevent overcutting in corners, as it slows there, resulting in a deeper cut if the output remains constant.
This is with light wetting, not actual casing. And painters' tape over stitching holes to lessen smoke/char. Those tend to really gather it.
I have been told under a certain power output (some said 15%) there is no difference, but experimentation appears to contradict that. 
Once you run a test pattern on each thickness of leather, your parameters should remain relatively close. Just write it down or save your test piece.
Hope you're having fun with it.

*Note: "my" laser is actually a makerspace unit. My local-ish library has a maker lab and lasers. But the big private maker space has better equipment and less bureaucracy if something breaks. I did the math and realized I could be a member a long time before I began to approach the cost of buying my own. There was some initial discussion about my using it commercially, but I was able to demonstrate that I only really  need to use it a few minutes at a time at relatively low powers so they've been happy to have me aboard.