Cheap Shrink Fit Test - Part 1

​I like to show when experiments don’t work out.

Recently, we traveled to a customer to tap-test milling tools. One of the assemblies was a new ½” shrink fit, but they had not yet received their shrink machine.  At the shopping center next to my hotel was a Harbor Freight store and they had a 1500 watt heat gun on sale for $15. We used the gun to first heat the bore on the toolholder and then the outside of the taper end. Within a minute or two the carbide endmill dropped right in. We let it cool and it was ready to test. It gave us an idea.

What if we could make a low priced rig to load and unload shrink fit holders using this cheap heat gun? So, we went to Home Depot and bought a wire chicken BBQ stand. It was designed to hold a beer can (diameter was a little to big for a CAT40), so we bought a PVC pipe adapter to reduce the hole size but also to provide a little more height for removing the endmill. The thinking was that if we inverted the tool once it was heated to the right temperature the endmill would just fall out. No need for a temperature sensor, but we bought a $9 non-contact infrared thermometer gun from Rural King anyway. We also bought a small plastic turntable to rotate the tool.  Total investment was less than $40.

Results next.