Making a Conoco Gas Truck, Part IV

While I was waiting for my replacement cutter to arrive, I did some cleaning up in my workshop. I should do this more often because I found some cutters I didn’t realize I had, including another 1/32” long-reach cutter! After quite a few hours, I finally finished milling both halves of the mold.

Now for the moment of truth—injecting a part. And disaster! Well, maybe not disaster, but certainly not what I was hoping for. I shot plastic into the mold and then I couldn’t get the part out at all. Stuck solid. Grump. In looking at my mold design I discovered I only had a 2 degree draft on the inside walls and no draft angle on the outside walls. That’s way to little draft, especially for such deep walls. So, I’ve adjust the draft angle on the inside walls to be 8 degrees. Fortunately, this is just removing more metal, so I don’t have to start all over. And I can mill out the plastic that’s stuck in the mold while I’m at it. This, of course, will take a few more evenings…