Saturday, May 28, 2005
PPSh-41: Upper Receiver Latch
The piece on the left is simulating the big hunk of steel that forms the breach of the gun. If it isn't obvious, I made this piece by sandwiching a bunch of 3mm sheets together...the reddish stuff is putty.
For those who are unfamiliar with firearms operation, the breach is the part at the back of the barrel where the bullet is inserted. Eventually I will drill a large hole in the back of this piece to accommodate a barrel. The small hole that you see now is where the upper receiver is attached to the lower receiver.
The other piece is the latch that locks the upper receiver down to the lower receiver. I heated a sheet of plastic with the heat gun, stretched it over the wooden form that I made before to get the main arch. Then I heated the end and just SMUSHED it around to get the rounded end. A little sanding, a little putty and it looks like it was always one piece! The gripping edge was just some careful carving with a metal file. I then cut a long rectangular slot out of the top and attached a small piece of plastic that I heat bent around a pencil. This area will house a compression spring that keeps the latch closed.
A "L" shaped piece was glued on to the end that will fit into a slot on the lower receiver. Note the spring in place.
On the REAL receiver, a small "U" shape is cut into the top and the metal is bent up to form a catch for the spring. Since it would be extremely difficult to replicate this with the plastic, I just cut a piece and glued it on.
The completed latch! You can see the slot where the tab is inserted on the lower receiver. The white dot on the side of the latch is a pin that goes all the way through both the latch and Upper receiver. The pin actually runs in a small slot on the receiver (visible 2 photos up!) that allows it to move back and forth about 1/4"...enough for the latch to disengage.
It starts to take shape AT LAST! And the best part is that EVERTHING FITS AND WORKS! Yea! Me am smart!
¶ 10:25 PM 
The piece on the left is simulating the big hunk of steel that forms the breach of the gun. If it isn't obvious, I made this piece by sandwiching a bunch of 3mm sheets together...the reddish stuff is putty.
For those who are unfamiliar with firearms operation, the breach is the part at the back of the barrel where the bullet is inserted. Eventually I will drill a large hole in the back of this piece to accommodate a barrel. The small hole that you see now is where the upper receiver is attached to the lower receiver.
The other piece is the latch that locks the upper receiver down to the lower receiver. I heated a sheet of plastic with the heat gun, stretched it over the wooden form that I made before to get the main arch. Then I heated the end and just SMUSHED it around to get the rounded end. A little sanding, a little putty and it looks like it was always one piece! The gripping edge was just some careful carving with a metal file. I then cut a long rectangular slot out of the top and attached a small piece of plastic that I heat bent around a pencil. This area will house a compression spring that keeps the latch closed.
A "L" shaped piece was glued on to the end that will fit into a slot on the lower receiver. Note the spring in place.
On the REAL receiver, a small "U" shape is cut into the top and the metal is bent up to form a catch for the spring. Since it would be extremely difficult to replicate this with the plastic, I just cut a piece and glued it on.
The completed latch! You can see the slot where the tab is inserted on the lower receiver. The white dot on the side of the latch is a pin that goes all the way through both the latch and Upper receiver. The pin actually runs in a small slot on the receiver (visible 2 photos up!) that allows it to move back and forth about 1/4"...enough for the latch to disengage.
It starts to take shape AT LAST! And the best part is that EVERTHING FITS AND WORKS! Yea! Me am smart!
¶ 10:25 PM
