What machine makes this stitch?

[Happy Hooligan]

This is from a WWii B-2 Cap.  What machine makes this zigzag with a double needle top?

I get they sewed the two pieces together, but then they did this double top stitch with the zig zag on the bottom.

?

 

 

[kgg]

1 hour ago, Happy Hooligan said:

but then they did this double top stitch with the zig zag on the bottom.

This is made with a fur / sheepskin sewing machine. Example: finished seam at 2:10 mark

kgg

[Happy Hooligan]

I thought that also, but the stitch on the original looks more zig-zag than bonis fur?   

[Northmount]

@Happy Hooligan moved your post to leather sewing machines.

 

[Constabulary]

Right side of the picture looks like a french seam and top and bottom thread appear to be of a different color. I´m not sure but I would say this was done with at least 2 machines. One double needle machine (with 1/4" gauge set I guess) and then a serger or fur sewing machine for reinforcing the inside seam. But I´m really not sure.

 

 

[Michael Sheldon]

The stitch is basically the same as what a single-needle serger does. The sideways mechanism is downright fascinating.

[CowboyBob]

They used a zig-zag machine with a double needle something like a Singer 107w it has a single bobbin that connects two double needle stitches together as it sews.

[ojd]

Looks like an interlock topstitch on a shuttle stitch seam. Common on old jersey sportswear, but in that application you have a spreader thread on top 

If you look closely it looks as if there are loops on the wrong side typical of chainsewing machines.

Union special made feed up the arm machines for top stitching seams like this, i.e. needle plates, feed dogs and presser feet for shaping the seam allowance like this. Never seen it in leather though but the machines are more than capable of garment weight leather.