Delrin can be pricey stuff. Our local plastic store sells it for about $12 per pound in large quantities. That looks substantially higher than the price mentioned here. But, sometimes there is a machine shop liquidation, and you can pick it up for $6 per pound. You don't see one of these every year, though, so it's not like just going to the store. One day, I went to a liquidation sale, and an old guy came up to me and asked me if I wanted any delrin. He liquidated an eviction, and filled up a storage unit with drops. For him it was free, but he said he'd give me a good price. I don't know what the price was, but it was probably in the range. This definitely doesn't happen every year. I've been making all my change gears on an as needed basis out of home cast aluminum melted with excess brush from required clearing. That costs less per pound than the delrin. I finally broke down and bought a 3/8" sheet at a liquidation sale for about $6 per pound. Shortly afterwards, I found a box of change gears for sale at another liquidation, so I have a piece of delrin that I'll probably not use for a long time. I tried putting a drop of acetone on it to see what would happen in contrast with ABS. Very interesting. Totally worth it, I think.
