Author Topic: I like shiny things....... (Read 1361 times))

Tack Driver 10 · « **on:** February 02, 2019, 09:51:45 PM »

Gold, silver, platinum, it's all good.
But for my next air gun project it's got to be stainless steel and brass.

Why stainless steel?
Because rust never sleeps.....LOL

Got some 3/4" OD T-316 SS tube to make some pump tubes.
The tubing as received isn't ready for prime time.
Honed the ID from .618" to .621" and gave the OD an initial polish.

This tube is cut to 20" and is destined for my next project.
A 2200 based 31xx chassis gun with a 1" longer pump tube.
The longer tube will allow a full brass valve instead of the short 2100/2200 valve.
Could possibly be the recipient of a balanced valve/multi shot configuration.

mav72 · « **Reply #1 on:** February 02, 2019, 10:22:18 PM »

Don’t make it too shiny.

The finger prints will annoy you.

Rick67 · « **Reply #2 on:** February 02, 2019, 10:30:03 PM »

Mr. Don Cothran had planned to manufacture stainless steel 13xx tubes but encountered some problems with the "fissure" (the bottom opening where the lever goes up and down) as cracks would materialize.

Probably he uses a hydraulic stamping machine of some kind.

I pray success on your endeavor, Tack D sir

Tack Driver 10 · « **Reply #3 on:** February 03, 2019, 12:03:52 PM »

Thanks for the tips.

I'm more of a brushed metal kind of guy.
The tube has a slight tiger stripe pattern in it from the manufacturer that I like.

Stainless steel is work hardened so aggressive stamping or compressing can lead to cracking.
I'll be milling the slots so should be OK but I'll keep an eye on it, just in case.

We're all skating on the thin ice of modern life and cracks are inevitable.
Just got to keep moving in the right direction.....LOL

Tack Driver 10 · « **Reply #4 on:** February 04, 2019, 04:41:55 PM »

Machined the slots and holes on the back end of the tube.
Just need to cut the pump slot and drill some holes for the pivot arm.

Here it is with the breech/barrel and trigger frame attached.
The tube will be trimmed about 2" to around 18".

BoostCreep · « **Reply #5 on:** February 05, 2019, 01:42:36 AM »

Tack Driver 10 · « **Reply #6 on:** February 05, 2019, 12:42:39 PM »

Milled the pump arm slot and drilled the holes for the barrel band.
The gun will use a NOS 766 pump link with the protruding rivets so needed to make clearance.

The stroke will be 4 3/4" with a 12 1/2" pump arm so will be easy to pump to high levels.

2K1TJ · « **Reply #7 on:** February 08, 2019, 07:29:24 PM »

Coming along nicely!

Are you finding that the stainless is any harder to machine than regular steel?

Tack Driver 10 · « **Reply #8 on:** February 08, 2019, 09:16:08 PM »

Quote from: 2K1TJ on February 08, 2019, 07:29:24 PM

Coming along nicely!

Are you finding that the stainless is any harder to machine than regular steel?

The 316 SS is quite a bit more difficult to machine.
Like a dog on a stainless steel steak house bone, I was all over it....LOL
Carbide drill bits and coated carbide end mills are a must.
Lots of oil and light passes milling the slots gets it done.
Definitely not a high production material.

Of the few SS tubes I've seen made, 304 SS seems to be the popular choice.
It's almost half the cost but also not as strong and corrosion resistant.
I'm guessing the Crosman tubes are some type of mild steel alloy.

As the saying goes, "Better ingredients, better pizza."
In this case, "Better materials, better air gun."....LOL

Here's a link to a build by Chevell using 304 SS and a 140 tube/pump link.
http://buddyl.com/edr/air/Crosman/chevell_build_pumper.htm

2K1TJ · « **Reply #9 on:** February 09, 2019, 02:57:53 PM »

Thanks. I may need to upgrade my tooling before attempting a stainless tube build.

I had read that build by Chevelle years ago, but it was nice to read it again. I was always a fan of his work.

Tack Driver 10 · « **Reply #10 on:** February 10, 2019, 08:26:51 PM »

Made the front pump arm pivot support from brass.
Used tapered SS 10-32 hex bolts and a black oxide shank bolt for the pivot bolt.
The mounting holes are slightly oversize so the bolts wedge in when tightened.

The brass nut is contoured to fit the curve of the tube so the bolt can't spin.
The bolt enters from the RH side so when the gun is pumped it will attempt to tighten.

Hoosier Daddy · « **Reply #11 on:** February 10, 2019, 09:27:29 PM »

Subscribed!

Rick67 · « **Reply #12 on:** February 10, 2019, 10:12:42 PM »

Looks overbuilt and tougher than a poso negro

https://www.google.com/search?q=poso+negro&rlz=1C1CHBF_enUS761US761&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjjiI6ezbLgAhVG_4MKHX_mCNkQ_AUIDigB&biw=1600&bih=740#imgrc=h6cm0QJAclfQYM:

Insanity · « **Reply #13 on:** February 10, 2019, 11:13:39 PM »

You have my attention.

Tack Driver 10 · « **Reply #14 on:** February 12, 2019, 06:38:10 PM »

Made the valve, a three piece affair.
Sort of an air gun Menage a Trois....LOL
Just in time for Valentines day.

Cut the original top just ahead of the check so there's minimal dead air space and max volume.
This allows the ultimate in flexibility by altering the internal valve volume.
Regular valve, high volume/multi shot or even a balanced valve.
Like a box of chocolates except you know what you're getting....LOL

Machined the floor back .080" but left the throat at .200" as it matched the new .157" port nicely.
Cut the seat at 22 1/2 degrees along with the Delrin valve stem.

BoostCreep · « **Reply #15 on:** February 12, 2019, 07:34:31 PM »

beautiful work!
I'd absolutely love a custom stainless tube/lothar barrel hpa/bulk co2 2240, with a nice set of olive wood/pearl resin grips.

Tack Driver 10 · « **Reply #16 on:** February 14, 2019, 12:35:29 PM »

Made the piston.
It's made to resemble the old Ash Can pellets.

Hoosier Daddy · « **Reply #17 on:** February 14, 2019, 09:05:59 PM »

That is a work of ART!

Tack Driver 10 · « **Reply #18 on:** February 14, 2019, 10:17:12 PM »

You may also like these versions from my "Gallery".....LOL

A modern version of the pellet piston.

My favorite, a NASCAR inspired racing piston.

Skillet · « **Reply #19 on:** February 15, 2019, 03:55:19 PM »

Ron, I am so impressed by your work! I think you're having almost all the fun!

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I like shiny things.......

Author Topic: I like shiny things....... (Read 1361 times))