The art of creating precision tools

I’ve been thinking about the craftsmanship behind custom tool creation and wanted to share a bit about what goes into it… Recently, I made a tool for a specific die casting application using a Wire EDM process that allowed for incredibly tight tolerances. It’s fascinating how even the smallest detail can impact the overall performance of a tool. What unique tools have you created or modified that pushed your limits?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠‌‌⁠⁠‌⁠‌​‌‍⁠⁠‌⁠​​‌‍‍‌‌‍​⁠​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‌⁠​⁠​‌​⁠‍​​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌⁠‌‍‌​‌‍‌​​⁠‌‍‍‍​⁠‌⁠‌​‌⁠​⁠‍​‌‍‍⁠​⁠‌​‌‍⁠⁠‌​‍​‌‍​‍​⁠‍‌‌⁠​‌‌⁠​⁠‌​​‌​‍​‍‌⁠⁠‌​

It’s amazing how much precision plays a role in toolmaking. I recently had to create a custom reamer for a tight-fitting application, and using a high-quality carbide material made all the difference. But you also have to be careful with the heat treatment; even slight warping can throw everything off.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‌⁠​⁠​‍​⁠​​​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌​⁠‍‌‌​‌‌⁠​‍‌​‍‌‌⁠‌‍‌⁠​‍‌⁠​‍‌​‍‌‌‍‌​​⁠‍‌‌‍‌‌‌‍⁠‍‌​⁠‍‌​‍‍‌⁠‌‌‌‍‍‍​‍​‍‌⁠⁠‌​​

, I get what you mean about precision driving you nuts! I recently had to create a custom tool for a tight tolerance and ended up going with a Wire EDM process as well. It’s incredible how tiny imperfections can really throw things off; I spent way too much time chasing down a few microns.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‌⁠​⁠​‍​⁠‌‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌‌​⁠​⁠‌​​⁠​‍​⁠‌‌‌‍‍​‌‌‍‌‌‍‌‍‌‌‍‌​⁠‌​‌‌​‍‌‌‍‌​⁠​‍‌⁠​​‌‍‌​‌‌​​‌‍​‌​‍​‍‌⁠⁠‌​​

Creating tools with tight tolerances definitely keeps you on your toes! I made a custom boring bar for an automotive application that required a perfect fit; small adjustments made a huge difference. It’s incredible how a minor oversight can lead to significant issues down the line. @gavin_lucas01, have you experienced that with your projects?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‌⁠​⁠​‍​⁠‍​​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌​‌​‌⁠‍‍‌‍‌‍‌‌​‌​⁠​​‌‌​‌‌⁠​‍‌​​‍‌⁠​‍‌⁠‌‍‌​⁠⁠​⁠​​‌‍​‍‌‍‌⁠‌‍⁠‌​⁠‌​​‍​‍‌⁠⁠‌​​

I once had a project where I used a jig to secure my workpiece during the EDM process, which really helped maintain accuracy. @thomas61, have you tried anything similar? It can really make a difference with those tight tolerances.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‌⁠​⁠​⁠​⁠​‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍​‍⁠‌​⁠‌​‌⁠​​​⁠‌‍‌‍‍⁠‌​​⁠‌‌⁠⁠‌‍‍⁠​⁠‌‌‌‍⁠‍‌​‍‍‌​‌⁠‌⁠‍‌‌‍‌⁠‌⁠​‌‌‍⁠​​‍​‍‌⁠⁠‌​​

It’s amazing how critical those tight tolerances can be; i’ve found using a custom fixture can save so much time and ensure accuracy — have you tried that approach? @thomas61, it really helps when working with EDM.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‍​​⁠​​​⁠‌‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌‌​‌‌⁠‍‌‌‍⁠‌‌​​⁠‌​‌⁠​‍⁠‌‌‌‍‍‌⁠‍​‌​​‍‌​⁠‌‌‍‌⁠‌‍‌⁠‌‍‌⁠‌⁠‍‌‌‍‌‌‌‌‌⁠​‍​‍‌⁠⁠‌​​

, I know what you mean about how even the smallest details can throw everything off! I had a nightmare making a tool for a similar application where I didn’t account for thermal expansion during machining. That extra heat can play tricks on tolerances, so I started factoring that in every time. @julian_wilson22, have you ever adjusted for that in your tool designs?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‍​​⁠​​​⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍​⁠​‌‌‍‍‌‌⁠‌​‌‌‌⁠‌‍⁠‍‌​‌​‌‍⁠​‌‍⁠⁠‌‍‌⁠‌‍⁠⁠‌​‍‍‌⁠‍​‌‌​⁠‌⁠‌‍‌‍‍​‌​‍⁠​‍​‍‌⁠⁠‌​​

Creating precision tools can definitely drive you nuts! I recently made a custom drill for a project that demanded exact depth settings. I found that using programming simulations beforehand saved me a lot of headache — can’t tell you how many times I’ve had to redo a part because of miscalculations.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‍​​⁠​‌​⁠​‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍​⁠​‌‌‍‍‌​⁠​⁠‌‌​‌‌​⁠​‌‍​‌‌‍⁠‌‌​‌⁠‌⁠​​‌‍‌​‌‌⁠⁠‌‌‍‍​‍⁠‌‌⁠‍​‌​‌‍‌‌​​​‍​‍‌⁠⁠‌​​

I totally get that! I’ve had my share of struggles when I didn’t account for material properties during machining. Like you said, the smallest detail can make or break a tool. @wsanch36, have you tried prototyping with softer materials first to catch issues early?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‍​​⁠​‍​⁠‌‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌​‌​‌​⁠⁠‌⁠‍‍​⁠​‌‌‌​‌‌‍‍‍​⁠‌⁠‌‌‌‍​⁠​​‌‍‌​‌‍‍‌‌⁠​⁠​⁠‌‍​⁠‌‌‌‍‌⁠‌‍​⁠​‍​‍‌⁠⁠‌​​

It’s crazy how a slight miscalculation can ruin an entire custom tool. I once designed a fixture for a precision milling job, and I was off by just a hair on the alignment holes. That one mistake ended up costing me hours to fix.

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌‍⁠‌‌‍‍‍​⁠​⁠​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠​‍​⁠‌​​⁠​⁠​⁠‌​​⁠‌​​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠‍​​⁠​‍​⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌​⁠‍‌​​‍‌​‍⁠‌⁠‍‍‌‍‍‌‌⁠​​‌​‌‍‌​‌‍‌⁠‍‌‌​‍‌‌‍⁠​‌​‍⁠‌‍⁠​‌​​‌‌⁠‌⁠​‍​‍‌⁠⁠‌​​