Paintball

[CJOttawa]

Another relevant thread is linked here: Nelson Powertube and Spring dimensions

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Howdy all!

This thread is meant as a technical discussion of issues surrounding the power tube in the very short-barrel guns such as micro-Phantoms and the Redux. (6-8" barrels typical)

The Redux uses breech drop, CCI Phantom internals and comes with a powertube bored to Lapco #6 specs. (typically a #4, bored out)

Issues with this type of tube

• delicate it is, especially near the gas inlets, due to thin walls
• flow rate; tubes with thicker walls and smaller ports are lower flowing

EDIT - and thank you very much Mr.Bacci for the mother of all posts!

EDIT 2 - after sitting in my gear trunk for about a year, I tried a modified WGP Ranger Powertube with amazing results.

Originally Posted by CJOttawa

This powertube is significantly higher flowing, requiring less dwell to achieve the same gas discharge.

Modified WGP Ranger Powertube:









With no other change to the gun, I went from about 275fps to over 300fps. I couldn't turn the velocity down enough and had to drop the red (heavy) hammer spring, substituting a blue (medium) spring.

I expect the 10-32 threads will never break and they leave a lot of metal around them to support the ported end of the tube.

CCI cupseals are extremely easy to drill and tap to 10-32 threads: use a #25 drill bit designed for the purpose and the 10-24 tap will easily cut the brass.

If you go too far with the drill, you'll punch straight through to the back of the cup. I doubt this is a problem; the seal will still seal.

The first attempts to drill the tubes were made with a standard 3/16" Titanium-Nitride coated bit.
I do NOT recommend this.

Buy a 3/16" oversize, right spiral fluted REAMER bit with bevels at the tip. The spiral flutes and bevel tip prevent the reamer from catching on the ports and, being a reamer, it leaves a cleaner surface than a drill bit.

Here's the exact reamer I bought on Amazon.com:
http://amazon.com/o/ASIN/B002PHNB2A

The photos are similar but not the same; it actually has a much longer fluted section, almost the whole length of the powertube. I suspect it's long enough to work with bore drop tube.

[bacci paintball]

Here is a comparison list I put together showing different Redux compatible powertubes.


In my Redux I have been using both a stock Ranger powertube and a modified Ranger powertube. I haven't done any tests with the following shown modified Ranger tube so I can't comment on it's efficiency other than the fact that it seems to work as well as the stock Ranger assembly in the warm climates of Northern and Southern California. The mentioned tubes are pictured below...




Top tube is a stock WGP Ranger powertube with the hybrid seal (built into the valve retaining screw). I have replaced the seal with an oring. On stock hybrid Ranger powertube assembly there is no seal on the stainless cup. Threads on this powertube are a massive 10x32.


Second from the top is a modified Ranger powertube with a Line SI valve retaining screw and modified brass phantom cup seal. The phantom cup and (rebuildable) seal have been drilled to accommodate the 10x32 threads.


Third down is the tube that came out of my redux which is the standard modified Lapco #4 which has been drilled out and shortened.

I am not sure if the base ports are enlarged. It is shown along side a lapco plastic cup seal (left column). Threads on this cup seal are 6x32.


Forth down is a stock modern phantom powertube assembly. With the stock Cup and stock rebuildable seal. Threads on this tube are a longer phantom 6x32.


And the 5th down in the cup seal column is an 8x32 cup seal I attempted to retap to 10x32.




The above image shows a close up of the hybrid ranger powertube assembly set up. The only difference between this setup and a completely stock ranger powertube set up is that the completely stock setup would have a white seal in the valve retaining screw instead of the black oring.




Here is a comparison of the stock hybrid WGP powertube (left) vs the hybrid valve retaining screw which I placed an oring in. In this picture the stock valve retaining screw has a powertube stuck in it (opps).




This picture illustrates the length which a stock ranger powertube protrudes from the valve retaining screw. (Closed Valve potion)

Approximately 1.75 inches.




This picture shows the inner diameter of a stock ranger tube. Approximately .169 of an inch.




This picture shows the inner diameter of the base ports on a stock ranger tube. Approximately .105 of an inch.








Here is the modified WGP ranger powertube assembly which has the 10x32 threads and Phantom cup and rebuildable seal modified to fit (drilled and tapped cup and enlarge seal center hole). The Valve retaining screw is a Line SI.




A larger picture showing the drilled out phantom seal.




This picture illustrated the length which the modified ranger powertube protrudes from the valve retaining screw. (Closed Valve position)

Approximately 1.75 inches.




This picture shows the inner diameter of the modified ranger tube. Approximately .204 of an inch.




Here is a picture of the base ports of the modified Ranger tube. Because of the 10x32 base these holes are able to be drilled out and still offer a significant amount of metal around the base ports.

The diameter of these 2 base port holes are .15 each.




This picture illustrated the length which the stock Redux (modified ((cut down and drilled)) Lapco #4) powertube protrudes from the valve retaining screw. (Closed Valve position)

Approximately 1 and 15/16th inches.




This picture shows the inner diameter of the stock Redux (modified ((cut down and drilled)) Lapco #4) tube. Approximately .191 of an inch.




Here is a picture of the base ports of the stock Redux (modified ((cut down and drilled)) Lapco #4) tube. This tube has 6x32 threads.

The diameter of these 3 base port holes are approximately .13 each.





This picture shows a stock modern phantom powertube assembly.




This picture illustrates the length which the stock modern phantom powertube protrudes from the valve retaining screw. (Closed Valve position)

Approximately 1.625 inches.




This picture shows the inner diameter of the modern stock phantom tube. Approximately .176 of an inch.




Here is a picture of the base ports of the modern stock phantom tube.

The diameter of these 3 base port holes are .095 each.






These pictures show the crack which has developed at the base of the stock Redux (Modified Lapco #4) tube. Because of the narrow base and the enlarging of the inner diameter the base was left with too little metal and has cracked.






These pictures show the difference in the thread size between the top Stock Redux (modified lapco) valve tube which is 6x32, middle ranger tube which is 10x32, and the stock phantom which is 6x32.






Here is a size comparison between the base of the modified Ranger tube and the stock Redux (modified Lapco #4).




And the exposed based port inlets when the modified ranger (left) and stock redux (modified lapco #4) (right) are equipped with the valve retaining screw and cup seal.




Here is a (well used) lapco cup seal I tried drilling out and tapping to 10x32 threads. When enlarging from 6x32 or 8x32 threads to 10x32 I tried a stock Lapco as show above, a NW Spitfire 8x32 cup seal as shown in the first picture, and a brass phantom rebuildable cup seal. I found the easiest to enlarge and most stable would be the rebuildable phantom tube.


When I got my Redux I began using a stock hybrid ranger valve assembly (white seal in valve retaining screw with stock ranger tube) because of the cracked stock tube. This assembly worked well in my Redux with the right springs.


I have not done extensive testing with the drilled out/modified ranger feed tube and rebuild-able phantom cup seal but immediate tests after switching from the stock hybrid ranger valve assembly I didn't notice much increase in velocity or shot count but actual differences between the two would be interesting to see with a determined test.


Ranger tubes are a great commodity for modifying because of the thick base threads and when drilled out extensively they appear to remain strong but continued use will be the real determining factor.

[ironchef97]

DAMN!!!! That was one of the best posts ever. Very informative, thank you Dan .

[tymcneer]

Ok... One of you all with a Redux, a set of Imperial calipers and a CAD program... Can you all make me a drawing of the Redux power tube?

I have an idea, but don't own a Redux, nor can I afford one... Unless someone would like to donate one to my project

Thanks,

Ty

[CJOttawa]

Originally Posted by tymcneer

Ok... One of you all with a Redux, a set of Imperial calipers and a CAD program... Can you all make me a drawing of the Redux power tube?

I have an idea, but don't own a Redux, nor can I afford one... Unless someone would like to donate one to my project

Thanks,

Ty

Hey Ty!

It's IDENTICAL to a Lapco #6, having had the tip cut off to fit a CCI Phantom.

Powertube details here:
http://www.mcarterbrown.com/forums/p...imensions.html

Originally Posted by new2pump

So a shortened lapco #6 will be fine? Just making sure for when the inevitable happens to R018.

Yup. You can cut just about any power tube to fit, including the Lapco #6's.

Remember: the Redux uses almost bone-stock CCI Phantom internals.

[PB Weasel]

Well, I had my first PT partially break at the gas inlet ports, on the original mOngo PT. I knew something was wrong because the gun would partially vent the twelvie down the barrel every 15 or so shots. One of the sidewalls between the gas inlets cracked, just as yours did CJ, only I caught it before it fully snapped. Luckily I had a brand new Lapco #6 PT kicking around and cut her down with a cut-off wheel. The new one works fine, just had to screw in the TPC just under two turns to get R018 shooting at 270FPS again. Figured I would throw this out here.

[CJOttawa]

Originally Posted by PB Weasel

Well, I had my first PT partially break at the gas inlet ports, on the original mOngo PT. I knew something was wrong because the gun would partially vent the twelvie down the barrel every 15 or so shots. One of the sidewalls between the gas inlets cracked, just as yours did CJ, only I caught it before it fully snapped. Luckily I had a brand new Lapco #6 PT kicking around and cut her down with a cut-off wheel. The new one works fine, just had to screw in the TPC just under two turns to get R018 shooting at 270FPS again. Figured I would throw this out here.

Hey PB Weasel. Thanks for the feedback.
I've linked to your post in another thread, discussing broken powertubes:
http://www.mcarterbrown.com/forums/r...powertube.html

[CJOttawa]

This powertube is significantly higher flowing, requiring less dwell to achieve the same gas discharge.

Modified WGP Ranger Powertube:









With no other change to the gun, I went from about 275fps to over 300fps. I couldn't turn the velocity down enough and had to drop the red (heavy) hammer spring, substituting a blue (medium) spring.

I expect the 10-32 threads will never break and they leave a lot of metal around them to support the ported end of the tube.

CCI cupseals are extremely easy to drill and tap to 10-32 threads: use a #25 drill bit designed for the purpose and the 10-24 tap will easily cut the brass.

If you go too far with the drill, you'll punch straight through to the back of the cup. I doubt this is a problem; the seal will still seal.

[CJOttawa]

Originally Posted by chopper duke

CJ, did you source the Powertube from a complete gun or Bacci or other?

Give me until next week to confirm details - long story.

Better story: my intent is to source several of these, put them through stress tests and have them duplicated from S7 tool steel.

Scratch that - Ty seems to have done this already so we just need to get him to make some more:

Originally Posted by tymcneer

So... I finally got some time in the shop...

Here is what fell off the machines. Please pardon my inability to use a camera.

The problem...



The solution...




Some information...

Made from S7 tool steel. Flame hardened. The original cupseal was threaded 6-32 (I think), but the powertube broke at the top of the threads. Having nothing to lose, I chucked up the cupseal and drilled and tapped it for 10-32. I made the PT to match.

Unfortunately, I have not had a chance to air it up and check out whether or not it works

Ty

EDIT - source was Dan Bacci (a year ago!) but I didn't want to burden him with hundreds of inquiries. He's cool with being mentioned; he's already done the Redux community a huge favour posting the photos above.

[DSA]

Originally Posted by cjottawa

Though I've read about them several times, I have yet to see a LineSI "lifetime" tube.

C6quad has one on his Advantage, Ross invented these as the original Promaster was rolling out the door. So it had to be 1990-91. Then over night the whole paintball scene went semi and Line SI Boulder went out if business. I doubt he ever gave Jerry Dobbins the design. Basically he threaded the PT instead of turning it down. This also required he create a new deeper cup seal which made it one heck of a drive train albeit too late to capitalize on it.