ADA: Ask Doc Anything!

[DocsMachine]

Where on the body do I drill a SL68 II for the gas line when building a VSC version?

-According to this ancient pic I scanned from a paper photo of my SC-SL back in 1996 (and unfortunately scaled for the 640x480 monitors of the day) ...



I'd say about an inch forward of the rear plug. Pull the rear plug and measure the depth of the valve chamber with a thin rod or stick. Use that to mark the outside of the gun, then lay the endcap on the side, and mark how far it screws into the body. Drill and tap your hole in between those two marks.

(I do still have the original paper photo of that somewhere- I've meant for years to re-scan it at a higher res. But then, I still have the gun itself somewhere, and I've been meaning, also for years, to dig it out, re-polish it, and see if I can't finally fit it with a tighter-bore barrel.)

Doc.

[Junglepeanut]

-Of course! I'm long since out of parts, so I'll have to make it all from scratch. How much of a hurry are you in? At this point, I'd really like to get my benches cleared off by the end of the year, so if you're not in a huge hurry, I'd like to suggest either sending the gun or body in (for a proper fitting) or making the 'official' order after the beginning of the year.

Doc.

Not in a huge hurry, just itching to have it complete. I will get back to you in the new year

[un2xs]

Why are BOA barrels so highly regarded? Was there a secret that only BOA knew? Were they that much "better" than other barrels offered at the time? Are they matched by modern barrels?

[un2xs]

In a previous response you said that ICD Desert Foxes could have become great in another generation or two. What would have made a third generation better? Can it be done to an existing Fox or would it need to be designed in from the start?

How would this hypothetical Fox 3 compare to a Mag? Is it worth bringing to market now?

[DocsMachine]

Why are BOA barrels so highly regarded? Was there a secret that only BOA knew? Were they that much "better" than other barrels offered at the time? Are they matched by modern barrels?

-To answer that question, we need to go back a few thousand years.

When discussing swords, the katana is generally regarded as one of the finest styles, and the early master-craftsman-made blades the finest among those. To the point they're considered, by the... well, the unwashed masses, to be the finest ever made, and not surpassed even today.

And those masses aren't just referring to the quality and care of it's creation; no, some unknown-unto-this-day aspect makes them sharper, they stay sharper longer, can cut right through lesser swords, etc. Technology lost and supposedly unequaled even by today's metallurgy.

Which is of course, horsecrap. It's purely a form of... I don't know, call it "established rumor". The katana was the superior sword during the Edo period, so to those who don't know any better, they're still the best-ever sword even today. (Movies, TV and comic books don't exactly try to correct this misconception, either. )

What it is, is that for it's time, yes, it was a top-quality weapon. First off, they used actual steel- or at least a form thereof, where much of the rest of the world was still using wrought iron (not much different than today's mild steel.) second, the lamination of the steel with iron made a more flexible blade- an iron sword would bend and stay bent, a steel one would bend and spring back. The softer iron blades were never really "sharp", they were generally more of a bludgeoning or stabbing implement. The far sharper katana could effectively cut and slash.

And so on. And that reputation has been repeated and repeated, so that someone hearing "the best sword ever made" today, makes them think, well, in that case it must me sharper than a ceramic chef's knife, more flexible then a epee`, can chop through a granite boulder, etc. etc.

Which is of course not the case. It was one of the finest weapons of it's day, and still considered very good even today, but modern metallurgy and computer-controlled heat-treating and the like, can produce a superior blade, and in days, rather than in years.

The BOA enjoys the same sort of situation. In its day, it was a very good barrel, in large part simply because it was one of the very, very few aftermarket barrels even available at the time. Generally speaking, they were typically slightly tighter bore than a typical factory barrel of the day (though not by much) were finished a little smoother, and were hard-chromed to boot.

So they were very good barrels, and out of the maybe half-dozen or so aftermarket barrels even available back then, definitely among the best.

At the time.

Today, they're only okay. They were made back in the big-paint era, so you'll rarely see one that mics under about .688, with .689 to .692" being more common. They're just a typical smoothbore, with their one remaining feature being a generally minimal amount of porting.

Basically they're cruising on a 20-year-old reputation that's long since been superseded these days.

Doc.

[DocsMachine]

In a previous response you said that ICD Desert Foxes could have become great in another generation or two. What would have made a third generation better? Can it be done to an existing Fox or would it need to be designed in from the start?

-Ooh, good question, but one that's going to be tough for me to answer. It's been a good long time since I last had a DF through here, and even then, I wasn't really analyzing it with an eye towards future improvements.

Of course, there's simple stuff like switching it to 'Cocker thread, a vertical ASA, a 45 frame and a proper 2-finger trigger, and giving it vertical feed. Apart from that, I seem to recall one of the main complaints was inefficiency- somebody could play with chamber sizes and bolt weights to see if they can't bring that up a bit. It'll never equal a modern spooler, but can probably be better. And wasn't there an ROF issue? Like the reg couldn't keep up? ICD has always had notoriously bad regs, so some better technology here would also likely pay off.

I'd have to get one in and play with it before I could speculate further. I'm definitely not an expert on this one.

Is it worth bringing to market now?

-No.But don't get me wrong, that has less to do with the 'Fox itself and more to the overall market. And the fact is, there's kind of no market for it anymore. Players today- new ones- want one of two things: Dirt cheap or high-end. They either want it as cheap as possible to get into the sport, or they want the best money can buy, because of course the more you spend on your gun, the better a player you are.

The 'Fox design simply can't compete, even upgraded, with modern spoolers or rammers. That means it'd have to be an entry level gun, and it's too expensive a design for an entry level. We'd be back to the same thing ICD found with the PRP- it'd be considerably more expensive than competitors, but without really offering much extra by way of performance. And there's very little "mid level" market markers out there right now- there's a few, sure, but WAY less than there used to be.

If we ever get back to the heady days of the pre-recession nearly-double-digit growth, with some updating it could be a viable design to bring back, in a limited way. But for the forseeable future? Nope.

Doc.

[DavidBoren]

Why do we have to choose between L-stocks and T-stocks when the vertical piece could easily be made to mount in both positions?

Two horizontal threaded holes in the butt-end of the horizontal arm would allow the vertical piece to attach in several positions, would they not?

[DocsMachine]

Why do we have to choose between L-stocks and T-stocks when the vertical piece could easily be made to mount in both positions?

Two horizontal threaded holes in the butt-end of the horizontal arm would allow the vertical piece to attach in several positions, would they not?

Doc.

[Silvester17847]

Work is sucking big time today, so I'll bite...


Doc,
How difficult would it be to fabricate a drop-in semi-auto mechanism (not pneumatic cocking) into a stock Nel-Spot 007 body & frame without structural changes?

[DocsMachine]

How difficult would it be to fabricate a drop-in semi-auto mechanism (not pneumatic cocking) into a stock Nel-Spot 007 body & frame without structural changes?

-If you already have a known, proven, tested design to go by? Fiddly, I'm sure, but straightforward.

If you don't have a known, tested design, and have to clean-sheet it yourself? There's where it gets tricky.

It's theoretically possible, sure. Obviously some sort of simplified, compact Automag valve, or close to it. Personally, I've always wondered about making a 'Mag valve with a small enough dump chamber you could run it on unregged CO2.

The biggest trick I can think of is how to make a trigger work. We can basically assume you'll have to replace the trigger, but for the moment we may still be able to make it drop-in, without requiring a new frame.

The problem is, making a super-short dump-chamber valve that short- the length between the nose of a 007 bolt and the end of the sear, which is what, about 1-1/2" at best? With an extended trigger, you might be able to move the "on off" rearward a tad more to gain more room.

Maybe something like an Equalizer or Desert Fox valve? I'd suggest a spooler, but that would require something like an Emek trigger valve mounted in the frame, and some way to connect it to the spool... and I don't think there's room for that.

One main thing to keep in mind? The insert body would have to have a "sleeve" of some sort, to convert the breech of the gun into a bore drop. The stock breech-drop chamber combined with semi-auto bolt speeds turns into a blender in a big hurry.

All in all? Not impossible, but also not very bloody easy... Line SI was working on a "drop in" unit for Bushmaster pumps back in '89. Did indeed look vaguely like a sort of self-contained 'Mag valve, but of course nothing ever came of it. And once actual semiautos came out, there really wasn't much reason to keep working on development.

Send me a nice weighty down payment and I'll get started.

Doc.

[grendal50]

A system similar to a DSDS Semi might work, it's basically what you're talking about. The valve is a small tube with holes around the outside, when you pull the trigger it pushes out with pressure, blows its wad and gets pushed back in with a spring where its held with a sear.

[Silvester17847]

I was thinking along similar lines re: AutoMag - my knowledge of AutoMags is incredible shallow.
My thought was a bore-drop sleeve to act as the front spring seat, but it would require some sort of alignment system to keep it from free floating and closing the opening.
My ideal concept is to not replace the trigger, maybe use a spacer plate with the A-Mag sear to ride and rock on the stock trigger.
After that, I come to the extent of my understanding...

Another thought would be electric with a rocker switch and maybe AA or AAA batteries in the stock trigger frame.

I had drawn up a mechanical semi-auto drop-in based on a Tippmann right as the auto-Traccer was coming out, end of the PMI-III era...
I never got beyond Patent-Pending, certainly no proof of concept prototype... :-(

Not being a machinist sucks!


:-)

If I could afford to send you a down payment, I would...
But if I could afford to pay you what it would take to make this, I could afford to learn to run the machines and buy them - I know what your skill is worth. :-)

[Indeed]

Doc, have you taken a look at the Humphrey solenoids to see if they will work for the led manifolds?

[DocsMachine]

Doc, have you taken a look at the Humphrey solenoids to see if they will work for the led manifolds?

-I've got them in, and they're on the bench, but I haven't had much free time to fiddle just yet. I'm going to have to dig out- excavate is more like it - one of my spare LED bodies and sit down and do some fitting. I have no doubt the solenoid will work, the only question is will it fit.

And, since I never ginned up a proper drawing back in the day, I need to take the finished part, once it's fitted and tested, and do up a proper dimensioned drawing, and/or a workable CAD model.

Doc.

[DocsMachine]

I was thinking along similar lines re: AutoMag - my knowledge of AutoMags is incredible shallow.

-Well, it's tricky in a lot of not-so-commonly-known ways, too. A 'miniaturized" Automag system, for example, if made with a small enough dump chamber to be able to run unregged CO2, would end up having an incredibly fast bolt speed. Fast enough that I suspect heavy ball breakage would be a serious and chronic problem. (Keeping in mind that one of the chief features of the Level 10 bolt is that it intentionally slows down the first part of the bolt travel, which goes a long ways towards paint survivability.)

So with that in mind, unless we could add a LOT of mass to the bolt some how (lead? tungsten?) a spooler might wind up a better bet, and that opens up an entirely different set of problems to solve.

Doc.

[grendal50]

http://www.warpig.com/paintball/technical/paintguns/sidekick_semi/index.shtml

[XEMON]

I've been wanting to get my hand on one of those ... They don't seam to pop up for sales much ...

[grendal50]

They are certainly fun to play with, I bought one new and still have it.

[Silvester17847]

What I dreamed up back in the day was a pseudo Tippmann with the valve body trapped between the forward and rear bolts inside the NelSpot body with four connecting rods instead of the one (thought process being alignment and spreading the cross sectional.mass to maintain strength), feed the valve thru the cocking knob slot with a standard Nel sear on the cable body. The stock valve body replaced with a sleeve that over laps instead of going in the main body and that contains the drive spring. Shrinking the valve to fit inside the Nel body made me think I would need to extend it a bit...

I might be able to dig up my old drawings if any of that made sense...