For those on the fence and interested in attending any of the Asmbly SIG, I can honestly say it’s always worth your time. Thanks to Dan(I think that was his name) at this months Laser SIG for the recommendation on using tapered bits to reach some finer detail in the CNC process and others on the overall process when I spoke during the Laser and CNC SIGs. Update below:
Sunday, I ended up ordering a 4-bit SpeTool set of tapered bits ranging in diameter from .25mm to 1mm.
Home machine: Vevor S4040
Bit: SpeTool W01004 1.0mm Radius x 1/8" Shank x 15mm Cutting Length x 1-1/2" Long 2 Flute SC TiAlN Coated Upcut Router Bits - rated at 18000, RPM – my machine has a max of 12,000RPM so I had to slow the feed rate down from the bits ideal rate for acrylic
Feed Rate: 500mm/min
Plunge Rate: 100mm/min
Stepover: 30%
Total runtime on my home machine for the stamp: 2 hrs 50 min.
1/4” acrylic stamp cut to 1/8” depth
Still a little effort needed but getting better…best part is I still have 3 finer bits to try!
I was thinking about how you mentioned That all the imperfections in the die show up in the leather and was thinking maybe a different plastic would give better results. I’ve made some badges with HDPE that had nice crisp edges so that might be something to try. Also might speed up machining time. Another benefit might also be that some HDPE sheets come textured and you could work that into your products.
I’ve got some scrap flat 1/4 white HDPE if you want to give it a try. Here’s a source for small pieces of many types of surface textures.
Great suggestion, I hadn’t considered HDPE. I just finished two more stamps yesterday, so far the tapered bits have really made a huge difference. I clear the large open areas with a tapered bit that is 1mm at the end and then finish the finer parts with bit that is .5mm at the end. I’m getting letters less than 3/4” in size with great clarity. I’ll share some more of the design I finished yesterday once I have a chance to press them into the leather.
Cast acrylic gives really crisp edges for these kinds of stamps, but it’s (a) more expensive, and (b) I used a laser for the entire process, and I don’t know how the material would do on a CNC:
1/4” cast acrylic to a depth of 1/8” is what I’m using now to make the stamps like the images at the top. The stamps so far I’ve only done on CNC. I’m taking to laser course next week to explore options. I cut this Texas one yesterday. The other is Celtic love knot I showed during the SIG.
Here’s a few more I completed this week. Really hit the mark on the feed rate with the two tapered bit I’m using. 1mm tapered bit to clear out the largest areas and then a .5mm tapered bit to clean up the fine detail.
