CowboyBob

Standard garment machine like a Singer 241.

The problem with either one of these is getting a shuttle or even the shuttle tension spring.If ever need one they are almost impossible to find.

The LR point will make a zig-zag look to your stitch(which some people like),if you want it to be straight get the S point.

The 42-5 has a lifting cam that lifts the feet underneath the end cover,the 31K47 has a cam on the top shaft(and rod on back) that makes both feet lift as they walk.So yes the both are spring loaded walking aka hopping feet.They both need the feedog to pull the outside foot back.The feet don't interchange between this 2-models the 42 & 16 class use the same feet.

Adjust it,the speed reducer has 2-bolts you can loosen & lower it down to tighten it.

You need more foot pressure to hold the leather down or try to hold with your hand as all machine won't sew correctly if the material is lifted while your sewing,if it's an old dried out piece of leather you need to oil or wet it to soften it up. The group on FB is China Leather Shoe Patcher

Yes we do but you can also get it @ TSC or Atwoods or even a auto parts store it needs to be 3/8" wide.

Yes,M57 is a 57" belt.

Should take a 214x1 needle

If your going to sew leather the Juki 1181 wouldn't be a good choice as the feed dogs can leave marks on the bottom of the leather where the 1541S with needle feed & walking foot the teeth can be polished off & as they are not needed .

We've found on thicker leather do to nylon being stiffer than poly it sews better with less skip stitches.The poly doesn't make a good loop for the needle to catch.

92 will be hard to thread on a #16 needle.

Yrs ago we used to use air pump pulley off Chevy engines,the water pump pulley will work too it's offset,you drill holes & bolt it on the the original pulley.

On another topic, I hear Sailrite now makes a smooth feed dog for these machines. It's nice to have it so it won't mark on the bottom but,I wonder if that would give consistent stitch length when sewing leather?

You would also get a lower speed since the motor pulley would be smaller than the one on the machine,so a motor with 200 rpm low speed would be 100 or less @ the machine on a standard setup.