We’re currently evaluating a Carbide 3D machine for our manufacturing shop at Boston Leather, and I was hoping to get some advice from the community.
We manufacture American-made leather products and are interested in purchasing a Shapeoko for cutting leather. Before making the investment, we’d like to know if anyone has experience cutting thick vegetable-tanned leather (8–14 oz) with good results. Ideally, we’d like to send a few pieces of our leather to someone for a test cut, or find out if Carbide has any way to help verify that our material will work well with the machine.
We’re also considering purchasing a Nomad 4 to produce small steel rule die components and prototype tooling in-house. We have an existing die file that we’d love to have tested before purchasing the machine. If anyone has a Nomad 4 and would be willing to run a sample file, or if Carbide offers any testing services, we’d really appreciate hearing from you.
Our goal is simply to make sure we’re investing in the right equipment before committing.
Any advice, recommendations, or experiences would be greatly appreciated!
The drag-knife heads that I’ve seen used online for the thicker leather tend to be the type that uses a Stanley knife blade. Donek is the kind-of-industry-standard brand I most often see mentioned but there are DIY equivalents for that style of drag knife. The little leather cutting I’ve done is by hand with Stanley and Xacto knives. I have a C3D Stingray drag-knfe cutter for my Nomad 4 but it is for much thinner material–vinyl sign material and cardstock are all I’ve cut with it so far.
I’d be interested in seeing an example die file just to see what they look like/how they work
For what it’s worth, I’ve done some (unknown) steel cutting on the Nomad 4. In my experience it’s been reliable so long as you’re careful and considerate of the limitations. The biggest issue with steel is the high speed spindle, it’s at odds with the low surface speeds that steels tend to prefer.
My understanding of steel rule die manufacture is that a very stable substrate is cut with a very narrow tool to a depth sufficient to allow a steel rule to be bent (if necessary) and placed within the channel and held securely so that it may then be used in a clicker or other press to cut out a material — classic example of this are the dies used to manufacture cardboard boxes and displays. The steel is usually not cut on the machine (though for production there may be a specialty tool for cutting the steel die to length).
There are a number of youtube videos on steel rule die making. This is one I remember watching.
PreciseBits has a page of steel rule die kerf cutters. The substrate I’ve usually seen (both in videos and years ago in person) is good-quality plywood but the above video uses plastic.
Usual preface, I’m with PreciseBits so while I try to only post general information take everything I say with the understanding that I have a bias.
Just going to address the die stuff. Generally speaking a standard die is made by cutting 2 baltic birch ply sheets and gluing them together. They have the slot for the rule on each outer side and the rule is driven into it. If anyone is going to attempt to do this that way it’s a nightmare. You have to have very good control of the deflection as you are lining up 2 board that are slot cut with the deflection then going in opposite directions. Typically the combined total that you can get away with is <0.005" before it’s a real pain.
If you are going to make a single board version that is much easier. However, as you are making a slot that holds the material by compression you have to be very mindful of the size of the rule (the box almost always lies), the tool diameter, and your total system runout (typically no more than 0.0002" industry standard). You also still have some deflection issues related to acceleration and the end of a cut or direction changes. It’s not as bad though.
On the laser side it’s an issue of getting the laser tuned for the rule size and getting enough depth of that size to properly hold the rule. Even in the production shops a cut rule is still considered superior and longer lasting, partially for these reasons.
Manual bending is it’s own skill even with tools made for it.
So not for the faint of heart. At least if you are trying for repeatability. But if you have questions about it let me know.
Yes, small diameter cutter is best to keep the surface speed as low as possible. I used a 2mm cutter with low rpm to cut 316 on my N3. But it is tricky because with such low power it is difficult to maintain a decently large chip and prevent rubbing/work hardening.
Sadly, a precision machine with more power is not available to me because neither HDM or N4 ship to Europe.
