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HEAL 2. Any suggestions?

Posted: Sat Jun 28, 2008 1:25 pm
by Ragnarok
OK, it won't be called HEAL 2, but I'm hoping to start building it sometime fairly soon, next couple of weeks most likely.

What I'll be building is the basic single shot configuration, which doesn't differ too much from the tried and tested mechanics of HEAL - and I'll retrofit with semi-auto later.

The design is partly finalised, but I'm still looking for ideas about improvements - I'm not perfect, and I seldom think of everything.

So far, the changes from HEAL boil down to:
> Pilot volume and dead space tightened up, a fairly obvious change to make.
> The main valve has a few dimensions changed to make it more efficent.
> I'm cutting back on hard edges within the internals by altering fittings. The hope is that this will improve internal flow.

Also, it will be a 500 psi cannon, not a 300 psi cannon, at least after I've got the means to reach that pressure :D

I may also at a later date do things like make a lighter piston and improved muzzle attachments (air stripper and "silencer")

There are a few things I'm not going to change, such as the distinctive "S-Kink" in the chamber, even if it doesn't help the performance any - I'm also planning on using the same rough dimensions and calibre.

So, chuck any (sensible) ideas you may have at me, any thoughts about performance tweaks, that sort of thing... even if it relates to something I've already said! You might have a better idea than me. The design is not yet set in stone, and I'm open to suggestions.

In other words, if you could have changed something about HEAL, what would it have been?

Posted: Sat Jun 28, 2008 1:34 pm
by Carlman
you need a scope :D

that is the only thing i would add to heal really so why not add it to 'heal 2'

Posted: Sat Jun 28, 2008 1:56 pm
by elitesniper
haha, glad your making some improvements:D, well more pressure is the only thing i would say, you should also add an oring inside where you breech is. :) heal jr is also on the way:D

Posted: Sat Jun 28, 2008 2:14 pm
by judgment_arms
Auto-cocker type mechanism for half-auto capabilities or at least something to automatically open the breach for you.

Also, try to avoid hose-clamps… it’s not the most professional looking. ;)
A nice, full-length wood stock to support the long barrel might help with accuracy.

Posted: Sat Jun 28, 2008 2:22 pm
by pizlo
Onboard Co2? Heal was pretty nice:P

Posted: Sat Jun 28, 2008 2:29 pm
by rp181
c02 sucks. i say try to get a nitrogen tank, try scott specelity gasses.

Posted: Sat Jun 28, 2008 2:29 pm
by MaxuS the 2nd
I think the judge said just about everything that i wanted to say.
Would be good if you had a nice walnut stock or something to go with it. I didn't particularly like the polymorph handle either to be honest..
I think a wooden handle would do the image good.

Why not fit it with a semi-auto system to begin with. It'll save time, money and a pain in the neck when it comes round to it.
Will you need to machine any of these components or is it just 'find what fits'?

Posted: Sat Jun 28, 2008 2:51 pm
by POLAND_SPUD
yeah that's it... semi auto from the very begining - if you want to improve HEAL that's all you need

EDIT
iron sights or a reddot sight would be nice too

Posted: Sat Jun 28, 2008 3:17 pm
by Fnord
The only way I can think to improve it is reduce the total weight and touch up the aesthetics a bit. If you want a performance boost, 500 psi will do it, but other than that I don't think the small tweaks to the pilot and flow coefficient will offer much improvement.

My (predictable)personal thought on metal pneumatics is: If I have to pump up this chamber to xxx psi, why not throw in some propane and get 5 times the power? (Make a hybrid out of it).

I'm not sure if your situation would allow this, but it would probably be worth it if you can. You'd need to do some serious re-designing though.

Posted: Sat Jun 28, 2008 4:11 pm
by judgment_arms
Instant half-auto:
Palmer’s Pursuit Shop Micro Pro Kit

The stroke is a bit short, but should be fine for marbles and paintballs.

Just have a linkage from your trigger to the four-way, it’ll take a bit to get timing right but once you do you’ll be able to shoot as fast as your pressure reservoir can re-fill.

Posted: Sat Jun 28, 2008 4:13 pm
by SEAKING9006
judgment_arms wrote:Instant half-auto:
Palmer’s Pursuit Shop Micro Pro Kit

The stroke is a bit short, but should be fine for marbles and paintballs.

Just have a linkage from your trigger to the four-way, it’ll take a bit to get timing right but once you do you’ll be able to shoot as fast as your pressure reservoir can re-fill.

:shock:


Care to fork over the bill-and-a-half it takes to BUY one of those?

Posted: Sat Jun 28, 2008 5:10 pm
by judgment_arms
SEAKING9006 wrote:
judgment_arms wrote:Instant half-auto:
Palmer’s Pursuit Shop Micro Pro Kit

The stroke is a bit short, but should be fine for marbles and paintballs.

Just have a linkage from your trigger to the four-way, it’ll take a bit to get timing right but once you do you’ll be able to shoot as fast as your pressure reservoir can re-fill.

:shock:


Care to fork over the bill-and-a-half it takes to BUY one of those?
What? $140u.s.d. plus shipping, considering copper pipe ain’t exactly cheap an additional, $140 bucks ain’t that bad. :wink:

Posted: Sat Jun 28, 2008 5:18 pm
by SEAKING9006
Yes, but alot of us don't even have jobs yet!


I've never had that much money at once.

Posted: Sat Jun 28, 2008 5:47 pm
by MaxuS the 2nd
SEAKING9006 wrote:I've never had that much money at once.
Haha, just you wait till you hold your first big wad of cash..

Posted: Sat Jun 28, 2008 6:50 pm
by Ragnarok
@Carlman: Way ahead of you there, HEAL has long since had a scope, although it did get nicked for a short while to go on my air rifle (while I sourced a better one): http://i210.photobucket.com/albums/bb12 ... P01256.jpg

@elitesniper: I was about to argue against that idea, because there have been problems with it in the past (the breech is specifically designed for high pressure, and most ways to put an O-ring in there would be detrimental).
However, I've just thought of a practical way for it to be done.

@Judge: I'd agree, I'm not a huge fan of the Jubilee clips, but they're hard to get around, because like HEAL, this will be a modular cannon with interchangeable parts, so things have to be firmly held, but also removable.
If you have a good suggestion for another, better looking, way to do that same job, you're doing better than I can.

I like the idea of the stock... although, I'll need to be inventive with it's design.

@Pizlo and rp181: I'm too much of a tightwad to pay for both gas and ammo, especially when I can get air for free, or close to it. :P

@Maxus: Actually, the staggered building has been the plan for a long time, and it allows me to concentrate on getting each bit right in turn.
I want a breech loader for the cannon anyway, and the parts for it sum to almost no cost at all, a few quid at most, so that's not a problem.

I did have a wooden grip at one point (picture here), but the problem was it wasn't particularly sturdy. The polymorph grip was the solution to that problem, because it was built over a frame of steel rod.

Judge's stock idea might work, but equally, that's more weight, and as Fnord points out, HEAL was heavy enough without that.

@_Fnord: Reducing weight is a little tricky. If I want a copper cannon in that size, the copper is several pounds on it's own, and the additions add up to surprisingly little.

And the tweaks are because I can - why waste performance when I have the means to deal with it?
Anyway, this is primarily a high velocity cannon, and because you lose more efficiency at these speeds, that means I have to fiddle with these things to get the best results.

As for the thoughts on hybrids - I'm a pneumatics guy, through and through. Not to say I never plan to build a hybrid, but for now...