Tuesday, November 8, 2011

Healthways Plainsman BB Pistol Disassembly, Part 3

Almost done…

The barrel end of the feed mechanism.

The BB hopper side of the feed mechanism.

The valve assembly is just pushed into the CO2 tube.
The cartridge is pierced and fills this chamber with gas. The o-ring was hard, it’s amazing that it was holding gas at all.

A snap ring holds the exhaust valve in the body.

Ok, a snap ring and a spring star washer holds the exhaust valve in the body.

I had to gently lever out the spring washer. The disk with the 4 holes allows the gas to flow.

Valve assembly.

For some reason the stem has a ground bevel on the end. Since there’s nothing to hold it in a particular orientation (unless it’s carefully aligned at the factory and then stays put?) I don’t see why.
I’m assuming that the rim of the seal holds the valve seal in?

I can’t tell if the stem is soldered, screwed or pressed in. No hint from the spring end. This is odd as the rest of the pistol is so repairable. But making a new valve stem would be easy I suppose. The pin diameter is the same as the Crosman guns from the era, but the seal is more like a Benjamin or Sheridan. I'll reuse it and if it leaks then I'll worry about making a replacement.
A standard sealing lip inside.

The cutouts in the valve body allow gas to flow around the end of the CO2 cartridge and into the valve.

The piercing assembly. Clip was levered out with a stout dental pick.

The piercing pin was pushed out from the other side (I opened the lever and wedged the pick up and into the hole.

An o-ring seals the pin.

It fits in this cup that looks to be staked in place. Yes, I put those two scratches at 12:00 on it. Oh well. It doesn’t matter.

I decided not to punch the lever pin out. those three notches means that it’s a press fit and has cut into the hole material. Better to leave it and not risk loosening the pin. The o-ring around the body (on the left) was hard as a rock.

A setscrew underneath the muzzle end of the frame.

Removed and a bushing for the barrel slips out.
So overall this was a unique design. I love design from this die cast era. Compared to the Roger or other die cast pistols, this has superior quality.

I’ll need to get some more 8 gram cartridges (I used up all I had with the Benjamin 30/30 debacle) to test after I get it back together.

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