The Evil Twin

[DocsMachine]

So, who bought this one?

-It is as-yet unclaimed, I was making it in large part as a test bed. I'll probably keep this one for myself, if anyone wants one, I can work up a quote, but really, we need to see if the thing will even work right, first.

I assume this is going to have a similar hammer / spring / valve set-up as the Vee-Twin? Since you are trying to pump out double the air through a single valve?

-The only thing different about the Vee-Twin valve is that it has two ports, due to the angle of the barrels. The Evil will use stock 'Cocker valves- in this particular case, I'll be using an off-the-shelf 11/16" Inception. (And have a fistful of Inception poppets to make the VT valves in the same configuration.)

One idea I've been playing with for the various doubles, is to bump the valve all the way up to 3/4". That'll require a custom hammer, too, but I figure since this thing needs so much air, a bigger valve chamber, a larger poppet and port, and a bigger/heavier hammer, would all help making full field speeds without needing huge pressures or mongo springs.

Unfortunately, I can't 'convert' any of the existing bodies, as they're already drilled. Simply reaming them out would make the bottom of the body just that much thinner, and as any 'Cocker owner knows, that rear grip frame screw already tends to be a little weak. So to do it right, the centerline has to be raised, to leave the bottom the same thickness.

So I figure once I get this lot done, and assuming the Evil works (IE, there isn't a dramatic difference in velocity between the barrels) I'll make another one as a test, with a 3/4" valve.

Doc.

[DocsMachine]

More happy pics!



























And that catches us up to current. I'll get back to it as soon as I can!

Doc.

[BlindFaith429]

Beautiful.

One thing that bothers me about this, is the barrels. With them being so close, I'm sure its a pain to thread in the second one. Or unthread it when they are both stuck in tight, no room to really grab and twist.

Wonder if it could work with like a 12" and a 14", thread the short one in first, and leaves you 2" of open barrel on the second to grab and thread in / out.

[DocsMachine]

One thing that bothers me about this, is the barrels. With them being so close, I'm sure its a pain to thread in the second one. Or unthread it when they are both stuck in tight, no room to really grab and twist.

-Hasn't been an issue yet, but we'll see. Then again, I very rarely get barrels stuck in my guns- keep the threads clean and maybe a drop or two of good oil on occasion, and no issues.

Wonder if it could work with like a 12" and a 14", thread the short one in first, and leaves you 2" of open barrel on the second to grab and thread in / out.

-Too much difference on the barrels and you may induce velocity swings.

Which will be interesting to play with either way. As noted earlier, maybe a different insert to slow down or speed up one ball, or just for the giggles of it, a 16" in one and an 8" in the other. I've got a pair of 14" Eigens, but they're different bores- then again, I'm not sure I can get paint that fits either one of them, so it may be moot.

Doc.

[DocsMachine]

Okay, a fresh update, now with comments!

As I said earlier, possibly in the other thread, a big chunk of the reason for this build was as a test bed. I'll be using the more modern 11/16" valves for these, and that requires different machining. I figured it'd be a smart move to do it on a piece that's NOT a paid-for customer part.

So, since I was getting to the valve-bore work on the Vees, I took a moment to try the milling in this body, to establish, among other things, the depths and bore sizes.

First, I popped the threaded grip-frame holes, then located and popped the valve-retaining/air passage hole and tapped it.



Then, the moment we've all been waiting for, finish-reaming the bottom tube out to size, and determining where there should be a "shoulder" for the valve to seat against.



Some bodies don't have a shoulder, but I figured that'd be handy for assembly. Anyway, after just one additional cut-and-try, I had it spot-on, and a dimension I can use for the Vee bodies.

Now, this vertical one is agonizingly close to being finished. It only needs a bit more millwork, maybe fab a couple bolts, and then a quick run through my junk bins to throw some workable parts at it. I could have it working (however well it's going to work ) by Friday if I had to.

But I have WAY too much on my plates right now, and several other customer who have been waiting patiently, so I need to switch focus to other things for a bit.

In the meantime, have a very bad mockup, using whatever junk was in a nearby parts bin.



And, if you're curious what it's like sighting down it...



We'll be back to this as soon as we can!

Doc.

[BlindFaith429]

Looks fantastic, excited to see it complete.

I bet you could shave quite a bit of weight if you could do similar milling to the Inception FLE body. Though I'm sure that's not going to be an easy feat on your Bridgeport.

Then, while I was thinking along the lines of weight savings, it made me wonder if half-blocking this would be possible. I'm sure that would add a whole new level of difficulty to this, but I wonder if it would make things easier on the pneumatics, moving 2 shortened bolts vs 2 full-length bolts. I don't know, just thinking out loud.

[Grendel]

So one air passage for both bolts so they will fire at the same time? Might make sense to open up the passage so you do not starve the top bolt when firing and then make the bottom bolt passage adjustable so you can tune them for the same velocity. Smart to go with the 11/16th valve so try and keep up with both bolt chambers. I actually like where this is going over the Vee Twin in form factor. Keep up the good work.

[Ecapnation]

Looks fantastic, excited to see it complete.

I bet you could shave quite a bit of weight if you could do similar milling to the Inception FLE body. Though I'm sure that's not going to be an easy feat on your Bridgeport.

Then, while I was thinking along the lines of weight savings, it made me wonder if half-blocking this would be possible. I'm sure that would add a whole new level of difficulty to this, but I wonder if it would make things easier on the pneumatics, moving 2 shortened bolts vs 2 full-length bolts. I don't know, just thinking out loud.

That would ruin all of the fun

[Ecapnation]

The more progress I see the more I want it....lol

[DocsMachine]

I bet you could shave quite a bit of weight if you could do similar milling to the Inception FLE body. [snip] Then, while I was thinking along the lines of weight savings, it made me wonder if half-blocking this would be possible.

-Oh, sure, there's all sorts of things that could be done, once we've shown that it actually works. (Assuming it actually does. )

But then, part of the appeal of a marker like this is it's size- there's an intimidation factor there. That's why I went with the old-style full-size backblock, rather than the later post-2K thinner blocks. (The bolts in the mockup are actually ex-Trilogy, and the bolt pin holes don't line up.)

This one'll get some mild, period-ish milling and I'll probably just anno it black. Anyone wants to try their hand at halfblocking or whatever, I'll be happy to try that on later models.

So one air passage for both bolts so they will fire at the same time? Might make sense to open up the passage so you do not starve the top bolt when firing and then make the bottom bolt passage adjustable so you can tune them for the same velocity.

-There's been some discussion about that, and considering that, as far as I know, Palmer's doesn't have any between-bolts velocity regulation on their over/unders, I suspect it's not necessary.

As for the air passage, one is generally limited by the valve retaining screw- the port through the body can only be the max tap/drill size for the 5/16" setscrew, which is .272".

There's also the fact that this is a high-pressure gun. Trying to get twice as much energy through the same valve pretty much by definition means you have to either drastically jack up the pressure or greatly increase the dwell- most likely, both. I'm hoping the bigger valve and valve chamber will let us keep the op pressure maybe a bit lower- Tim Firpo has a video over in the Vee-Twin thread showing off one of my early bodies, that he assembled and tuned. Said he had to push it to 750 PSI.

Hopefully the better valve and bigger valve chamber will let us keep it down around 600-ish.

The more progress I see the more I want it.

-You could write it off as a business expense. Just look at all that room for advertising and sponsor stickers!

Doc.

[Ecapnation]

Doc I sent you a pm..... There things to discuss

[Alexndl]

It would be fun to see it next to a Raimaker and a shoebox shocker, not sure the evil twin is that much bigger compare to those

[Cunha]

Doc - use all of your powers to make a single center feed over under work correctly. Make some ridiculous ass detents or something. DOOO ITTT

[Ecapnation]

It wouldn't be easy..... Here's what your up against.
.331...... Basically a half a ball bore gap

[BlindFaith429]

What about a pair of right-feeds, stacked on top of eachother, connected to a single vertical "stack".

You'd have to make the distances perfect so they dont jam in the split on the way down though. May have to adjust the angles too. Idk, just an idea that popped into my head.

[Ecapnation]

That's a jam waiting to happen

[Alexndl]

Could add paddle feed system like the Evil guns to prevent jam?
That would be "simple"... lol