Printable spring for wade's extruder

Some people get away without using springs on wade's geared extruder (http://www.thingiverse.com/thing:1794), but I felt that this was too sensitive to being over/under tightened. I wasn't able to find appropriately sized springs at the local hardware store either.

I did cut some longer springs down to size, but I also made these. At least in the short term, they seem to work about as well as actual springs. The biggest difference is that they don't have as much travel. In my opinion, that actually helps with loading new filament since you aren't fighting as hard to push the bearing back. I just made them today, so I do not know how well they will hold up over time though.

EDIT:
I have attempted a dozen or so prints using these springs. Most had to be aborted due to filament jams or bad settings, but I do not think this was related to the springs. They did develop flat spots on the side that presses against the idler block, but turning the screws one full revolution seemed to fi