I've mostly scavenged a few from dead click pens I had lying around. Some pens will have the blackish wire springs..those are the bad ones. You want the shiny silver ones. I've also found quite a variety in diameter sizes of springs and also lengths. Length is no problem..I just compress them a bit or cut them to fit, but finding the really small ones for my 510 carts is tricky, but the 901 carts will hold the bigger springs.
Best suggestion is to pay attention as you go around town, for businesses that give away free pens for advertising. Open one up and if they are silver springs, grab two freebies and you're set for awhile..LOL!
Best suggestion is to pay attention as you go around town, for businesses that give away free pens for advertising. Open one up and if they are silver springs, grab two freebies and you're set for awhile..LOL!