The sewing submission by TJG about Singer 66 Treadle machines is informative and “generally” relays the usefulness of such a machine, especially in a grid-down environment, however, as I have learned personally, her claims that the Singer 66 can handle THICK and BULKY items like leather and nylon is not accurate in my opinion. I learned this by buying a beautiful electric-motor-driven Singer 66 “Red Eye” model to do all the nylon web gear modifications I have always wanted to do to my gear, as the Singer 66 is indeed a tough all-steel sewing machine, yet I quickly discovered the weakness the Singer 66 had with thick, tough materials (as well as other old home sewing machines), that being thread tension capabilities. Thread tension is what constructs a strong stitch by pulling up the bobbin thread into the fabric, ideally half way into the center, and the Singer 66 without modification just doesn’t have the tension capabilities to pull up thick T69 or T90 thread into thick nylon or leather. Remember, these Singer 66’s were designed for normal household sewing tasks, such as dresses, suits, shirts and other thin fabrics. They were not designed to sew multiple layers of nylon strapping onto Cordura fabric.
However, mechanically-minded as I am, I was able to modify the thread tension assembly on the sewing head to allow it to place more tension on the thread, but even that had limits, as the design of the Singer 66 thread path would often cause the needle to flex from the thread tension being so tight which would then send the needle point slamming into the plate on the next downstroke, breaking the needle. True, sewing heavy leathers, fabrics and nylon webbing can be done with patience and test materials to get the tensions just right, but it is a frustrating hassle at times and not for the easily angered… But I confess, before I finally found a more suitable sewing machine for my purposes (Consew 206RB walking-foot industrial machine), I was able to create and modify quite a bit of web gear as well as make new upholstery covers for my retro vintage camping trailer.
Lastly, I found the lack of a reversing capability in the early Singer 66 machines the most frustrating of all. Without reverse capability to lock in the stitch by overstitching you end up having to [lift the foot and] spin the whole project 180 degrees to lock in a stitch. This is very difficult on thick or big projects, and time consuming.
My set up now is my Consew 206RB-3 walking-foot, industrial straight-stitch machine which has beautiful reverse capability and unbelievable sewing power and capability with thick materials using thick threads, and an all-steel-gears vintage NEECHI Super Nova home machine for thin materials that not only reverses, but does zig-zag for bar tacks and serging (keeping edges from fraying).
Shalom & YHWH Bless You! - R.S.