Saturday, May 21, 2011
Here we go--Hey, remember, this copy is not going to be an exact duplication of Anthony's work. I'm making a one-off based on his idea and design. His is the real deal that has gone through prototypes, testing and improvements.
Here's the spare 2240--yes, another gun from the Findlay, OH airgun show. Also scrounged up an extra 22XX valve and some brass rod
End seal on the stock valve. This one is pretty trashed. Got it used and the previous owner really overtightened the cap.
There's that piercing needle. Pressing the stem against the bench simulates the striker hitting the stem. That needle can restrict gas flow--especially when using a heavier hammer spring in an attempt to gain velocity.
Here's what I've been referring to as the 38T style piercing pieces. I have a slightly different threaded collar than what Rienecker uses.
Unscrewed the stock valve. Just trying to conceptualize how I'm going to proceed.
Cut off a 1.5" long piece of brass. Faced the ends and turned the end down.
Threaded 9/16-18 to fit the Crosman body.
Couldn't cut the full thread in the small lathe, so I transferred the work to the vise and chucked the die into a handle.
With a parting tool, I cut a groove for the valve body o-ring
Chamfered the end of the thread.
For concentricity, I threaded the piece into the (gutted) Crosman valve body and snugged it down. Took a very light skim cut to remove any runout between the halves.
Looked too long, so I used the parting tool again.
Spotted the front of the valve with a center drill.
Selected a #30 bit for the through hole.
After through drilling, I started an 11/32" hole then progressively enlarged it...
Until I finished the hole to 0.500" with a tiny boring bar. The 38T piercing pin and seal sit in the bottom this counterbore.
Had to make a quick run to Kromhard Twist Drill for an oddball 9/16-28 bottoming tap. The tap ran me $18.50 or so out the door at the good guy price. Vaughn at Kromhard is still waiting for the day when I just need a "normal" 1/4-20 plug tap. Don't hold your breath, Vaughn.
Only tapped the front half of the hole for the retaining collar.
More to come...
Monday, May 16, 2011
These pictures and notes show my progress, lack or progress and final success in resealing the 105…over the course of a month!
The valve assembly. I figured an o-ring would work for sealing the valve body in the pistol. Unfortunately the pistol leaked. So I spent some time trying to figure out the problem…I removed the brass cup that the valve spring fit in as I couldn't find it on the parts list.
This worked well, so I’ll have to try this in the future. The 80 durometer, being softer than the 90 durometer of the first seals, seemed to work much better. But the pump was not pushing much air into the valve…
I decided to use a modified Crosman 1377 pump cup. I’ve shown that several times on the blog. I turned down an old button head cap screw for the retaining screw as the cup is shorter than the cup used on the 105 originally.
Finally…I noticed that Derrick said the bolt on the 116 is supposed to have tiny balls between the bolt spring and the ID of the breech, and the 105 is virtually identical, so I dug some out and put them in. the bolt is quite smooth now.
I haven’t had time to check velocity, but it seems similar to the Crosman 130, which makes sense given the size of the pump tube. I’m glad it’s done, this pistol was punishing my self-esteem!