Singer 400W 103

Singer 400W-103
Uses Needle System Size 135X7 (I misspoke in the video)

[@mostlymetalmachines9249]

Looking at the Singer Instructions for 400w101 - 102 -103 & 105 Machines, Publication 2783w (pdf available online): Machine 400w103 - is the same as 400w101 except it has a 1-7/16 inch needle bar stroke and 3/16 inch presser bar lift, for stitching heavy and extra heavy weight fabrics. Sub-model -101 is the one for light weight fabrics. You mentioned difficulty with heavier weight fabrics. But I'm wondering if the underlying issue was not the weight of the fabric itself, rather trying to fit too many layers under the presser foot? Fabric weight vs fabric layer(s) thickness. Another KZbinr handle 'Cechaflo' has several videos on upholstery using a Singer 241-12 (rated for medium weights) that he has modified for heavier weight fabrics and he addresses presser foot height. He may have some tips that would be helpful for you. Other than being a heavy weight fabric machine, you have the bonus of a sub-model with a regular/long bed. Singer made sub-models with short beds that were 'artisan' or 'home manufacturing' targeted.

[@adriananoelle4699]

And what was the purpose of this design? Mere innovation? Thanks!

[@thepaulhowell]

I suppose it's an attempt to re-invent the wheel. 😆 Juki has a similar rotary machine, the DDW-9 series.