Sewing: Industrial Sewing Machine - feralcoder/shared GitHub Wiki

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Top Level Public Wiki: feralcoder shared I do car, sewing, wood, and other work in my SHOP One level up: Sewing

History

I got this machine over 10 years ago, to sew many layers of polyethylene tarp together to make a geodesic dome cover. It's a Mitsubishi LS2-210, and it punched that stack of tarps like a jackhammer in butter.

Rehabilitation

The table was always in bad shape, and the sewing head only ever got a rough tuning. This was good enough when handling thicker, predictable nylon thread and a huge needle.

I dug this out of storage after years of decay, most urgently to sew facemasks (under construction) for CV-19, and I have plenty of other projects stacked after that. Definitely not ready for service.

First I had to replace the table top, which was trickier than it sounds. I had to order it 3 times. First they sent the wrong one, then it was stolen after delivery, and finally I got this nice new one, made from plywood, not particleboard. I did have to custom fit the machine's feet into the table with a router.

Then I had some parts to replace - tension springs and nuts that got lost to time...

Even after getting table and head set up and doing basic tension tuning and thread timing, I could not get a reliable, or even good, stitch, under the simplest conditions.

Tuning

One thing I love about industrial equipment is this: when things go out of alignment, there are ways to dial alignment back into true. With home-grade gear you often have to resort to bending and flexing things that get sloppy. Design for adjustment is crucial for initial high precision and to keep the machine true as it wears. But it's also handy to adjust for different fabric and thread conditions, and can extend the very usability of the machine.

Basics:

  • top thread tension
  • bobbin tension
  • stitch length
  • forward / reverse

Nice tuneables:

  • fwd / reverse gradient
  • feed dog inclination
  • feed dog elevation
  • feed dog / needle timing
  • feed dog / needle alignment on 2 axis
  • feed dog / needle travel ratio
  • foot pressure
  • foot height (up and down)
  • hook/needle timing
  • hook/needle sweep distance