One of the best upgrades for your Class 7 industrial sewing machine is switching from the metal operator wound under bobbins used in the early 1900s to the pre-wound Style 41 bobbins (We detailed the advantages here).
You’ll need a bobbin pin in the shuttle casing to keep the pre-wound bobbin centered. Here are step by step instructions on how to complete the easy one time set up:
Step One – Remove Hook and Casing from Machine
Step Two – Release Bobbin Case from Hook Frame
Step Three – Remove Retaining Screw from Base of Bobbin Case
Step Four – Insert Bobbin Pin into Case
Step Five – Align Hole in bobbin Pin with Thread Hole in Bobbin Case Post
Step Six – Reinstall Retaining Screw
Step Seven – Insert Pre-wound Bobbin
While this pin is available from your local service center for $68.00, if you mention or respond to this blog post you can get one for free from Service Thread!