Sheet Metal Guys: Pexto ID?

[an0nymous]

This is on offer locally. Pexto No502 1/39. Might be a ...seamer? Can anyone tell me anything about it..maybe a video? Apparently my googlefu is weak.

 

[WWIIjeep]

This is on offer locally. Pexto No502 1/39. Might be a ...seamer?

The actual name for those is "grooving machine."

Specifically, Pexto called the model 502 a "short horn groover."

It was their smallest grooving machine.

Capacity is 20" and 24 ga. mild steel.

 

[an0nymous]

Thanks, Jeep! Sadly the original owner isn't really in shape to explain it's operation. Can you point me to a resource? I see lots of references to hand groovers but am having trouble finding one for this sort of thing.

 

[WWIIjeep]

A grooving machine is used to finish plain lock seams in sheet metal cylinders, like stove pipe or other round ducting.

The "hand made" equivalent of the grooving machine is a hand groover and conductor stake.

The process goes like this:

1. Make locks (180-degree bends) on edges of flat stock with a bar folder. The locks are typically 1/4" to 3/8" wide.

2. Make cylinder out of the flat stock with a slip-roll forming machine.

3. Hook the locks on the two edges of the formed cylinder together.

4. Flatten and groove the locked edges with the grooving machine.

I'll try to find a couple of illustrations of the process.