Crosman 1322

[jackssmirkingrevenge]

Finally found the time to make some progress on this:

Here's the new valve in brass compared to the old one in aluminium. Note the flat top on the new valve, I will be making a pump head to match soon.

This is what it looks like taken apart, note the balanced valve and separate eccentric check valve.

The valve is not exactly balanced in order to maintain a residual force keeping it shut. Even so, I was able to expand the porting to 7mm diameter over the original 5.5mm, while still having 20% less force keeping the valve closed.

The porting to the barrel is now 5mm diameter, though due to my pledge not to alter any original parts the barrel restriction of 3.4mm will remain.

This was made somewhat on-the-fly, here's the paper I was working off - dimensions are not necessarily correct but it gives you a rough idea of how it works:

[Labtecpower]

After shooting jake's modified 2240 I think i'll buy a 1377 or 1322 soon, and modify everything
I'll be watching this thread closely for inspiration

Very nice work on the valve!

[wyz2285]

The porting to the barrel is now 5mm diameter, though due to my pledge not to alter any original parts the barrel restriction of 3.4mm will remain.

Then not much will change, flow is limited by the lowest point.
I see you used a o-ring for seal, I made the exact same way for my airsoft gun. Even though the o-ring sits in a groove it sill get blow off some times and I was using much less pressure so bear that in mind...
Looks like (didn't calculate anything nor read the dimensions), the new valve set seems to have less chamber volume than the original?
Anyway, looking good. I wish I have the time to make something.
Edit: how did you make such good male threads? I found it quite hard for the die to "bite" onto the piece and often the thread isn't linear to the piece also I can't cut deep. Did you use a die holder on the tail stock of the lathe?

[Gippeto]

... it sill get blow off some times...

Been there...done that..with the same result. Delrin, Teflon or Urethane.

Nice work on the valve Jack. The results of your testing will be interesting.

[jackssmirkingrevenge]

Cheers all, it was nice to spend some quality time with the lathe also, this is the first hammer valve I've made from scratch.

The results of your testing will be interesting.

It's been quite inconsistent so far, I've been fiddling with different springs... sometimes it gives an almighty bang, other times two or three shots - with the same spring and number of pumps!

I think I'm going to re-do it with some more thought. I can't have more than 5mm diameter counterbalance because of the need for the separate check valve, so perhaps I should go for a smaller port - say 5.5mm - to keep the difference minimal. This would mean that there would be much less stress countering the hammer, so the stem can be thinner.

Then not much will change, flow is limited by the lowest point.

Well, yes and no - imagine the difference between filling a bucket from a water bottle, and filling it from a hose. Same diameter, different flow speed.

I see you used a o-ring for seal, I made the exact same way for my airsoft gun. Even though the o-ring sits in a groove it sill get blow off some times and I was using much less pressure so bear that in mind...

It seems to have held so far. Pretty much the same as used in airsoft valves.

the new valve set seems to have less chamber volume than the original?

Should be a bit more actually.

how did you make such good male threads?

Magic

Cutting male threads is the one aspect of machining I really can't stand!

Did you use a die holder on the tail stock of the lathe?

Yes, to start it off, then I move it to a vice and continue manually. What I usually do is make the part say 5mm longer and make this extention slightly smaller in diameter, usually half way between the thread major and minor diameter, and file the edge to a taper - and start cutting the thread with the reverse side of the die, once that is done I flip the die and do it properly. Use plenty of lubricant and quarter turn clockwise, then half turn anti-clockwise to break the chip. Once the thread is cut, I remove the extra part on the lathe.

[wyz2285]

It seems to have held so far. Pretty much the same as used in airsoft valves.

I know, but you're using a lot more pressure. Good luck though

Yes, to start it off, then I move it to a vice and continue manually. What I usually do is make the part say 5mm longer and make this extention slightly smaller in diameter, usually half way between the thread major and minor diameter, and file the edge to a taper - and start cutting the thread with the reverse side of the die, once that is done I flip the die and do it properly. Use plenty of lubricant and quarter turn clockwise, then half turn anti-clockwise to break the chip. Once the thread is cut, I remove the extra part on the lathe.

Too bad I haven't find one for my lathe. I also made the piece longer and thinner in the end, still can't cut threads deep enough, can't secure the piece from rotating with the die...

[Brian the brain]

JSR:

You need a way to bleed the counter-side in case some pressure leaks past the O-ring.
This can easily happen when you fill it from zero.

Nice to see you're doing exactly what I had in mind but was unable to do so far.
Now put together a kit including a barrel, bolt, etc to convert original Crosman's to 9mm.

And get rich.

[jackssmirkingrevenge]

Too bad I haven't find one for my lathe. I also made the piece longer and thinner in the end, still can't cut threads deep enough, can't secure the piece from rotating with the die...

This is what I had done before I got one



I had the same issues with Dimply as it was the first time I tried it, have a look.

You need a way to bleed the counter-side in case some pressure leaks past the O-ring.
This can easily happen when you fill it from zero.

There is a bleed hole, unlike the diagram the threaded port goes straight through the counter chamber. Unfortunately I was unable to access the holes to clean them up properly so it tears the o-ring going past it afer a few shots, meaning I had to limit travel. This is why I want to re-do it.

Now put together a kit including a barrel, bolt, etc to convert original Crosman's to 9mm.

I have another "Get rich" project with LeMaudit at the moment which is coming along nicely, hopefully I will have something to show soon

[Brian the brain]

I suggest discussing any further details on the CBHV in private...before any possible commercial gain is taken away by another party.

I'm still awaiting your job-offer..

I have a few more get rich idea's and one definate winner...just need the means to produce them.

[Gippeto]

Nice to see you're doing exactly what I had in mind but was unable to do so far.
Now put together a kit including a barrel, bolt, etc to convert original Crosman's to 9mm.

And get rich.

9mm conversions have been done in the past...not currently available AFAIK so you might be able to sell a couple to the hard core types. I have been selling .25 conversion kits for a couple years now and find it increasingly hard to move them even though those who've purchased them gave good reviews.


Keep having fun Jack...THAT is what airguns are about.

Regards

[jackssmirkingrevenge]

Well, made a new valve stem, ironed out some bugs that were causing inconsistencies and failures and now it seems to be working great. So far, noise has been my only perception of power and up to the 20 pumps I've tried it just keeps getting louder! Clearly the sweet spot hasn't been reached

Did a quick non-scientific power test by putting an airsoft BB in the transfer port (6.5mm bore) and clucking bell! It went through a cardboard box!

[youtube][/youtube]

My cellphone microphone really doesn't do justice to the noise, it sounds like a 22 rimfire at 20 pumps!

Now to make a new breech and see how fast it will throw some lead

Keep having fun Jack...THAT is what airguns are about.

Definitely - though to be honest, since this is such a widespread product I am reluctant to publish the details in case someone with a bigger manufacturing capacity than my little lathe and mill chose to make money off it, Brian does have a point. We'll see, still no idea what a difference it power this will make.

I'm still awaiting your job-offer..

Still finding my feet in the snow but the future is bright

[Gun Freak]

I had previously missed this. Following closely...

[jackssmirkingrevenge]

I had previously missed this. Following closely...

Noted, I will find a way to make it a hybrid

Comedy aside, here's the brass breech block I just finished, next to the naff stock plastic one:

Here's the underside:

It started off life as a 3/4" round bar, I loosely based the dimensions on the plastic one but made no attempt to replicate it. Nice and shiny but I don't think I'll polish it much more, I want to black it eventually anyway.

[FragmentedSanity]

Nice looking breech Jack. I prefer em in black too, but polished brass can look great on the right gun.

I didn't see any rails milled in, is it just set up for for the stock sights?

[Gun Freak]

I'm guessing you went with the flat top for accessories?