Back in the day, when old-timers set their Singer machines up for darning, they simply removed the feed dogs, and installed a blank needle plate. There were dozens of feed dog, needle plate, and presser foot combinations that were interchangeable for several models of the Singer “old iron” machines like the 31-series, 95-series, 96-series, etc. to set the machine up for specific tasks. It wasn’t even that unusual to change those three items on a regular basis to avoid having to purchase multiple machines. With just a quick change of FD, NP, & PF, the machine was ready to perform a different task. Many of those feed combinations are still available today.
The blank needle plate for your 31-15 is part number 12422. Here is a photo of mine shown set up on my 1936 Singer 96-40. It has no feed dog slots cut in it, just a needle hole.
CD in Oklahoma
Last edited by ThayerRags; 07-27-2015 at 04:12 AM.