Optimizing tooling and organization for prototyping

Having a tool changer is great, but 21 pockets doesn’t go that far when I need multiple sets of drills and taps (I’m just starting to experiment with combination drill/taps for some through holes). To give myself maximum flexibility, I’ve got basic end/face mills setup for steel and aluminum, and I’m leaving the rest of the space flexible for each job:

13D taster
2 1/8″ 3 flute finisher (Al)
3 1/4″ 3 flute finisher (Al)
4 1/2″ 3 flute rougher (Al)
5 2″ facemill (Al)
10 #3 center drill (Al or steel)
11 1/4″ chamfer mill (Al or steel)
181/8″ 4 flute finisher (steel)
191/4″ 4 flute finisher (steel)
201/2″ 4 flute rougher (steel)
213″ facemill (steel)

The center drill and chamfer mill are theoretically setup to minimize average tool change time, but since I cut mostly aluminum they probably don’t. I have mostly moved to drilling without center drilling first though, so that one at least is less critical.

The benefit of splitting these up along material lines is that if I need the space I can easily just pull all the holders for whatever material I’m not currently running. Theoretically I could pull the 3D taster most of the time as well, but I do use it fairly often so I haven’t gotten there yet.

The other factor in tool organization is what tools are permanently setup in their own tool holder, so I can set the offset and just switch them in as necessary (rather than have to remeasure, which is not that difficult but does add time). The biggest factor in that is cost, because it requires more tool holders, and I’m slowly adding to my collection as I get the opportunity.

I’ve found that SK16 collet holders are nice (low runout and lower torque required to seat than ER collets), and fairly inexpensive (a Maritool collet is ~$20, and Shars tool holders are ~$80). I have a previous post on my limited testing of Shars tool holders versus the Maritools here. The flexibility of a collet system is hard to argue with in a prototyping environment, although I know there are lots of people who would suggest heat shink or milling chucks (which are both out of my budget for now).

I have also discovered slitting saws and have been blown away by how effective they are for minimizing operations required for small parts. I was really surprised that they produce flat surfaces even when a very small web is left to hold up the part (I have been using 0.010″; in aluminum this snaps off with a couple bends).

I keep track of all of this using a Google Sheets document, so I can reference it on my computer in the shop and while programming in my office. I’ve made an example copy if you’re interested.