Built In Integrated Dual Feed Walking Foot Portable All Metal Sewing Machines
Additional Information:
Bonded Polyester threads size #69 and up were designed for walking foot upholstery machines sewing primarily on exterior fabrics with size 20-25 needles.
Juki TL and portable home sewing machines were designed for regular home sewing and quilting threads sewing primarily on interior fabrics with size 9-19 needles.
Not to say that it cannot be done, but top thread diameter clearances around the rotary hook may be too close to prevent jamming, even with size 19 needles.
We recommend using bonded nylon and polyester upholstery threads with portable walking foot or industrial sewing machines. John Douthat, Owner & Tech, AllBrands