My First Attempt At Making A 3D Stamp (And What I've Learned Is....)

[Studio-N]

.....It is difficult with a laser engraver. I've attached two pictures of two different 3D stamp attempts. First a little technical background:

Doing 3D with the laser depends on some specialized artwork. It needs to be a 16 bit (versus the normal 8bit) greyscale drawing. If you think of 8 bit as x and y coordinates, the part of the 16 bit drawing defines the height (power) of each of the shades of grey. Normal paint programs don't do this. CAD/CAM programs that talk to a CNC router for instance, do. Some will allow the output of the 16 bit drawing. Therein lies the first difficulty. COST. I'm playing with trial version of ASPIRE which is (only) $2K. Some programs go north of $8K. I'm probably going to pull the trigger on the ASPIRE software since i'll be going the CNC route work by the end of the year. Drawing programs like Corel Draw do let you do a gradiated fill in grey shade but it is still 8 bit and the results are more what is referred to as 2.5D. I've done a couple like that, and it worked ok for a dome or heart, but nothing with sharp transitions.

The second problem is PRESSURE. All of the 2D stamps I've done or used from the evil empire are basically outlines and while they can look quite good they are strictly 2D and easy to impress with a mallet. The 3D stamps from the evil empire really do require a lot of pressure. They are sold as hammer stamps but you really got to beat them good to get them to 'bottom out' and give a good raised impression or depression. I usually use a 3 lb maul but the press gives the best results.

So looking at the 1.5" STAR - this wasn't too bad. It's difficult to see here without an Isometric view, but you can see the line in the center of each point. This is the high point, and it does in fact slope down to the edge of the point. It probably slopes from zero to about 6 oz on this 9 oz leather. I tried it with the mallet, and no way. I had to finally press it on my 1 ton arbor press to get it to bottom out. There is some texture on the star but remember that these files are generated for a cnc router where the finish cut is a smooth bullnose router bit which leaves things baby smooth. There is a certain amount of separation between each dot for the laser which is generating the texture. It is something I'll have to play with when I get the real software but I wasn't upset with this result.

The Hat was more of an exercise in shading which definitely results in the texture. It definitely has the look, but the hat band and buckle didn't have a lot of definition in the file. That's something I can play with at another time when I have a dead day. So basically, I have a whole new respect for those guys making these on a CNC and what it takes to make them look good. I should have mentioned it took twice as long to cut these as they normally do. I'm going to look forward to getting the CNC and play more with making 3d stamps. Although it will work in Delrin, I'll probably switch to aluminum when I make them again.

Thanks for listening. I know this isn't about 'real' leather working but I do enjoy making them and thanks to a bunch of you guys and gals, I get to keep making them. Cheers!

[J Hayes]

I like them, nicely done!

[Studio-N]

thank you J. I think I figured out how to fix the hatband. Just a simple line to break the band from the hat texture should make it pop. Cheers!

[J Hayes]

Welcome. It sure would be fun to know how to run that stuff. Endless possibilities. Will you be able to cut steel stamps once you are CNC equipped?

[Studio-N]

in theory yes. Wood I know. Metals will be a whole new learning curve and mountain of broken bits.

I know soft metals are easy, but moving on to brass and stainless has special considerations.

There is a lot of info and videos on the internet I'll just have to find the best websites and study a while.

Plus I have to locate some suppliers. Cheers!

[irishsuperfly]

Thanks for sharing these examples and your experience so far! I'm very interested in the ability to create custom stamps and so far I've found that it's difficult to get good info on the process. My dad knows little about leather working but a whole lot about routers, machining, and molds - he pointed me in the direction of laser engravers thinking it would be an easier path than CNC. It's interesting to see that the laser left a textured surface. What material did you use to make your stamps? In the next week or so, I hope to give a test run of a stamp made with a 3D printer since it's the cheapest option available to me right now.

[Studio-N]

This was done in delrin. I've got my CNC machine on order so I know it will be useful on some of my applications, plus i'll be able to transition to some light metals as well. But I'll continue with the delrin on CNC since the material really only has to be harder than leather to work.

Don't forget that it's also important to have the right software to do this. Here is another stamp that was successful. While I'm not showing the profile, there is a slight dome to the crown of the skull on which I have added an anarchy symbol that sits atop the dome. The software has to create at least a 16bit greyscale to get a good result. 8 bit greyscales end up not giving you enough shades to attach different power levels to, so it comes out more blocky than the 16 bit. I'm using ASPIRE which is for CNC routers and is expensive. For regular 2D stamps (text, silhouettes, flat figures) I'm still working with Corel Draw which you'll find does a fine job.

As for the textured surface, it is a consequence of the greyscale. When you tune your machine, WHITE will be 0%. Which means only things at the surface level of the material. Every thing else is a shade of grey and gets hit with the laser at some power level other than zero. So the entire stamp face is one big pixelated surface (hence the texture). When you lay out a 2d stamp, it is 0 or 100%. so there are large areas that are untouched which form an even depth smooth impression. Once you do a couple it all comes together.

I have seen a couple of things done with the 3D printer and I think it will work. I also think it will leave a textured surface because while they don't advertise it much, much of the stuff 3d printed still requires a little sanding.

I have to say it's getting expensive for these new developments. It sometimes takes 3-4 iterations to get it the way I want it. But at the same time, I haven't had this much fun in years.

[irishsuperfly]

Thanks for all the info, Nick! As soon as I said delrin, my dad knew exactly what I was talking about. He knows someone with a CNC router he's going to put me in touch with. In the meantime, I made a simple name stamp in SketchUp and sent it off to the 3D printer guy. I'm really impatient to see how that works out, even if I have to do a little sanding or other cleanup work before using it. I'll be sure to post results in case anyone is interested.

[Studio-N]

I think it will work out fine. I don't know if the ABS plastic used to 3d print is brittle so for a plate a press would definately work best (no blunt force trauma like with a mallet). BUT, since you can print most anything, maybe you can have him print it complete with a handle so you can do a strength test.

Those 3d printers have definately come down in price. maybe someday after I recover the cost of the cnc.

While I'm waiting on the CNC to come in (next week I hope), I'm experimenting with making some embossing rolls. Another eye opener. But I've got one prototype done and redoing a second one that didn't work out (but I figured out why). I'll post some pictures once I get a nice looking strap done.

[Rossr]

If you don't mind me asking what kind of cnc are you getting? what programing are you going to run it with?

Ross