I was asked to post this, cause...

I was asked to post this, cause...

Joined: December 5th, 2007, 9:32 pm

January 29th, 2008, 2:04 am #1

Some of y'all may not have seen it, elsewhere. So here goes, it is a re-post, of my continuing efforts at customizing a $20.00 B3...

Starting from the inside out.... I really don't like that leather seal on the piston. I DO like that synthetic seal that comes with the South Summit kit....but it won't fit the stock piston.

OK....

Lets, make a new piston. We'll start by turning out a steel "button" for the seal to reside upon, and to "cap" our piston assy.

[/IMG]

Let's cut a piece of 1" D.O.M. steel tubing to length, and dril a couple of "sweat hole" so we can sweat solder the cap on with silver solder...

[/IMG]

After checking the spring fit, I decided to ream the inside for a smooth .015" spring clearance.

[/IMG]

Then it was time to sweat the cap on the tube....it was also a press fit, .004" interference. That baby ain't coming apart!

[/IMG]

Now I'll start releiving the body for compression cylinder clearance, and to reduce weight...

[/IMG]

That's enough for today...., tomorrow, I'll start on the piston "fantail," slot and weight matching to the OEM piston....




It was brought to my attention on the YF Chinese forum, that there is an easier way to adapt the synthetic piston seal to a B3, yesterday evening. And after close examination of the pics...I gotta agree! I'm still gonna continue with my full fab piston, but I had to make one of these seal adaptors too....

[/IMG]

[/IMG]

[/IMG]

That is really a COOL idea! Wish I'd come up with it....but I didn't...so I'll copy it! LOL!
Oh man, I love playing with aluminum on the lathe....so one thing led to another, next thing I knew, I was cutting about 3 inches off the thingying handle....

[/IMG]

Mainly so I could get back on the lathe...

[/IMG]

So I could make a new thingying handle...handle....and start on the muzzle break....

[/IMG]

[/IMG]

So now, I don't know which way to turn....finish the muzzle brake, or go back to the piston....it's all gotta get done...we'll just see which way the wind blows when I get back in the shop. :



I'm gonna get back to the custom piston next week. I just like rolling big swirls off aluminum...its almost addictive to me....

So that being said Day 3 involved finishing up the barrel breal, and installing with JB Weld...

[/IMG]

[/IMG]

[/IMG]





Day....something or other...anyway...back to piston fab. Started by turning a groove for a delrin guide ring in the fan tail area. Then millig a section for sear engagement...

[/IMG]

and milling a guide rod slot, for the thingying arm...

[/IMG]

Then after weighing the OEM piston, and finding it to weigh 200gr, and the new piston at it's present state at about 246.4 gram.....hmmmmmmmm, let's lighten this bad boy uo a bit....back in the mill, and weighed after each slot was cut. I ended up with 196.4gr on the new piston....

[/IMG]

[/IMG]

[/IMG]

Still got a little work to do, a spot weld in the sear disconnect area, and some hand fitting....yadayadayada.... but the piston will be done tomorrow. Then it's on to making a reducing bushing for the transfer port. Lot's to do yet, but almost 50% complete.



Hope this helps some of y'all... I'll get back to y'all with an update, when the metal work, and maybe a little plastic turning continues. Right now, I'm taking a break, and doing the stock...

kliff

Cr CS2240-.177(x2) "Sylvia" and "Elvira"

Crosman Sierra Pro 3-9X50AO scope .177, Quest 1000 4X32 scope .177, RWS34 .177.
Cummins B3(x2).177

Hy-Score 806, circa 1961, Daisey .177BB SA "Peace Maker," circa 1962, MkII/.177 circa 1977

http://kliff53.proboards101.com/index.cgi
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Joined: March 6th, 2002, 3:54 am

January 29th, 2008, 4:28 am #2

Looks like your on your way.

Very sneaky, though. Some of those pictures, hmmm.

Bryan
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Joined: April 4th, 2005, 6:09 pm

January 29th, 2008, 5:06 pm #3

Some of y'all may not have seen it, elsewhere. So here goes, it is a re-post, of my continuing efforts at customizing a $20.00 B3...

Starting from the inside out.... I really don't like that leather seal on the piston. I DO like that synthetic seal that comes with the South Summit kit....but it won't fit the stock piston.

OK....

Lets, make a new piston. We'll start by turning out a steel "button" for the seal to reside upon, and to "cap" our piston assy.

[/IMG]

Let's cut a piece of 1" D.O.M. steel tubing to length, and dril a couple of "sweat hole" so we can sweat solder the cap on with silver solder...

[/IMG]

After checking the spring fit, I decided to ream the inside for a smooth .015" spring clearance.

[/IMG]

Then it was time to sweat the cap on the tube....it was also a press fit, .004" interference. That baby ain't coming apart!

[/IMG]

Now I'll start releiving the body for compression cylinder clearance, and to reduce weight...

[/IMG]

That's enough for today...., tomorrow, I'll start on the piston "fantail," slot and weight matching to the OEM piston....




It was brought to my attention on the YF Chinese forum, that there is an easier way to adapt the synthetic piston seal to a B3, yesterday evening. And after close examination of the pics...I gotta agree! I'm still gonna continue with my full fab piston, but I had to make one of these seal adaptors too....

[/IMG]

[/IMG]

[/IMG]

That is really a COOL idea! Wish I'd come up with it....but I didn't...so I'll copy it! LOL!
Oh man, I love playing with aluminum on the lathe....so one thing led to another, next thing I knew, I was cutting about 3 inches off the thingying handle....

[/IMG]

Mainly so I could get back on the lathe...

[/IMG]

So I could make a new thingying handle...handle....and start on the muzzle break....

[/IMG]

[/IMG]

So now, I don't know which way to turn....finish the muzzle brake, or go back to the piston....it's all gotta get done...we'll just see which way the wind blows when I get back in the shop. :



I'm gonna get back to the custom piston next week. I just like rolling big swirls off aluminum...its almost addictive to me....

So that being said Day 3 involved finishing up the barrel breal, and installing with JB Weld...

[/IMG]

[/IMG]

[/IMG]





Day....something or other...anyway...back to piston fab. Started by turning a groove for a delrin guide ring in the fan tail area. Then millig a section for sear engagement...

[/IMG]

and milling a guide rod slot, for the thingying arm...

[/IMG]

Then after weighing the OEM piston, and finding it to weigh 200gr, and the new piston at it's present state at about 246.4 gram.....hmmmmmmmm, let's lighten this bad boy uo a bit....back in the mill, and weighed after each slot was cut. I ended up with 196.4gr on the new piston....

[/IMG]

[/IMG]

[/IMG]

Still got a little work to do, a spot weld in the sear disconnect area, and some hand fitting....yadayadayada.... but the piston will be done tomorrow. Then it's on to making a reducing bushing for the transfer port. Lot's to do yet, but almost 50% complete.



Hope this helps some of y'all... I'll get back to y'all with an update, when the metal work, and maybe a little plastic turning continues. Right now, I'm taking a break, and doing the stock...

kliff

Cr CS2240-.177(x2) "Sylvia" and "Elvira"

Crosman Sierra Pro 3-9X50AO scope .177, Quest 1000 4X32 scope .177, RWS34 .177.
Cummins B3(x2).177

Hy-Score 806, circa 1961, Daisey .177BB SA "Peace Maker," circa 1962, MkII/.177 circa 1977

http://kliff53.proboards101.com/index.cgi
I've got a million ideas for mods on airguns and powderburners.

Unfortunately for those projects, but fortunately for my wallet, I've got loads of "paying jobs" to do first.

I hate it when work gets in the way of fun!!

MM
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Joined: July 11th, 2001, 7:44 pm

January 29th, 2008, 11:26 pm #4

Some of y'all may not have seen it, elsewhere. So here goes, it is a re-post, of my continuing efforts at customizing a $20.00 B3...

Starting from the inside out.... I really don't like that leather seal on the piston. I DO like that synthetic seal that comes with the South Summit kit....but it won't fit the stock piston.

OK....

Lets, make a new piston. We'll start by turning out a steel "button" for the seal to reside upon, and to "cap" our piston assy.

[/IMG]

Let's cut a piece of 1" D.O.M. steel tubing to length, and dril a couple of "sweat hole" so we can sweat solder the cap on with silver solder...

[/IMG]

After checking the spring fit, I decided to ream the inside for a smooth .015" spring clearance.

[/IMG]

Then it was time to sweat the cap on the tube....it was also a press fit, .004" interference. That baby ain't coming apart!

[/IMG]

Now I'll start releiving the body for compression cylinder clearance, and to reduce weight...

[/IMG]

That's enough for today...., tomorrow, I'll start on the piston "fantail," slot and weight matching to the OEM piston....




It was brought to my attention on the YF Chinese forum, that there is an easier way to adapt the synthetic piston seal to a B3, yesterday evening. And after close examination of the pics...I gotta agree! I'm still gonna continue with my full fab piston, but I had to make one of these seal adaptors too....

[/IMG]

[/IMG]

[/IMG]

That is really a COOL idea! Wish I'd come up with it....but I didn't...so I'll copy it! LOL!
Oh man, I love playing with aluminum on the lathe....so one thing led to another, next thing I knew, I was cutting about 3 inches off the thingying handle....

[/IMG]

Mainly so I could get back on the lathe...

[/IMG]

So I could make a new thingying handle...handle....and start on the muzzle break....

[/IMG]

[/IMG]

So now, I don't know which way to turn....finish the muzzle brake, or go back to the piston....it's all gotta get done...we'll just see which way the wind blows when I get back in the shop. :



I'm gonna get back to the custom piston next week. I just like rolling big swirls off aluminum...its almost addictive to me....

So that being said Day 3 involved finishing up the barrel breal, and installing with JB Weld...

[/IMG]

[/IMG]

[/IMG]





Day....something or other...anyway...back to piston fab. Started by turning a groove for a delrin guide ring in the fan tail area. Then millig a section for sear engagement...

[/IMG]

and milling a guide rod slot, for the thingying arm...

[/IMG]

Then after weighing the OEM piston, and finding it to weigh 200gr, and the new piston at it's present state at about 246.4 gram.....hmmmmmmmm, let's lighten this bad boy uo a bit....back in the mill, and weighed after each slot was cut. I ended up with 196.4gr on the new piston....

[/IMG]

[/IMG]

[/IMG]

Still got a little work to do, a spot weld in the sear disconnect area, and some hand fitting....yadayadayada.... but the piston will be done tomorrow. Then it's on to making a reducing bushing for the transfer port. Lot's to do yet, but almost 50% complete.



Hope this helps some of y'all... I'll get back to y'all with an update, when the metal work, and maybe a little plastic turning continues. Right now, I'm taking a break, and doing the stock...

kliff

Cr CS2240-.177(x2) "Sylvia" and "Elvira"

Crosman Sierra Pro 3-9X50AO scope .177, Quest 1000 4X32 scope .177, RWS34 .177.
Cummins B3(x2).177

Hy-Score 806, circa 1961, Daisey .177BB SA "Peace Maker," circa 1962, MkII/.177 circa 1977

http://kliff53.proboards101.com/index.cgi
Cummins tool sale B3s that I've cobbled together into 1 gun that shoots way better than a $20 has a right to.

For my homemade R9 pistons I used to use DOM tubing at first. I don't know the grade but it had a finish that required a lot of work, and wasn't especially consistent in wall thickness. After a couple pistons I tried some 4130 chrome molly "aircraft tubing" I stopped using the the original tubing because the dimensional and surface consistency was much better and the stuff cuts great on my lathe with hand ground tool steel bits.

Anywhoo......here is a pic of my reworked and home fabricated B3 internals including a factory piston that was cleaned up and fitted with an oring sealed piston cap. I also turned a fitted spring guide (not quite finished in the pic).

Here is a pic of the completed B3 spring guide.......

My mods allowed me to get about 700fps with JSB pellets and even group pretty good using a 6x Burris Compact scope.

I even shot this 3 shot group on the paddle of my Gamo FT target using the gun with iron sights.
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