[modelman]

Cooper-I am also a "backyard machinist" self taught. I had problems with the cut-off tool until I learned how to sharpen it. If the tool is right and sitting at the correct height you should be able to go right thru that big stuff. Maybe some of the real machinist on here can help you. I think the delrin (plastic) will work just fine. In some cases it will outlast aluminum. Keep cranking!!