It's a pipe dream....


Postby D_Hall » Mon Sep 18, 2006 8:40 am

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by joannaardway
Err... Why were you doing that?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Aging studies. The stuff in question was 20 years old. What had the years done to it's chemistry? Sure you can look at the surface of it, but that doesn't tell you what's going on deep inside (away from surface effects). Only way to know that is to go exploring (I did do it by remote control, mind you).
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Postby D_Hall » Mon Sep 18, 2006 3:07 pm

And it looks like moving to a hybrid system makes valving easier. Pushing cold air I needed the 29 inch burst disc to get the flows I require. With hot air? Not so much. It's obviously not AS good as going with the 29 inch, but it looks like going with a 19 inch disk is acceptable. Thus the disk ought to be makable with much lighter material... 1/8" or something.
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Postby joannaardway » Mon Sep 18, 2006 3:35 pm

Remote control... I had these horrible images of you perched on a massive block of explosives with a power drill.

I thought it sounded rather off your companies safety procedures as an idea...

On the subject of sensiblity - how is recoil going to be compensated for?

I know that a massive steel contraption won't move much, but after a few launches, it might well have moved back a fair bit. Would it just be a case of towing it back into place with a hefty vehicle, or would it be bolted to something?
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Postby D_Hall » Mon Sep 18, 2006 4:06 pm

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by joannaardway
On the subject of sensiblity - how is recoil going to be compensated for?

I know that a massive steel contraption won't move much, but after a few launches, it might well have moved back a fair bit. Would it just be a case of towing it back into place with a hefty vehicle, or would it be bolted to something?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

I've got a flatbed low-boy trailer that we dont use anymore(*) and a big ol' diesel truck to move it with. The plan is to hard mount the gun to the trailer and just let the trailer slide/roll a foot or two when the gun is fired. Moving it back into place is no big deal. We've got some LARGE forklifts that could move it a foot or two or we could hook the truck back up to it.


(*) Originally designed to haul Polaris missiles. Put new tires/brakes on it and it's "mine".
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Postby joannaardway » Tue Sep 19, 2006 8:49 am

Sounds good.

I presume that ignition will be done with hefty spark plugs and capacitors.

Assuming safety, recoil, construction, mixing and ignition is sorted, then I can't think much further - other than loading procedure and launch angle.

How will you load your ammunition? - crane? forklift?

And will the firing angle be set, or cranked up to variable levels by some method?
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Postby D_Hall » Tue Sep 19, 2006 9:23 am

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by joannaardway
I presume that ignition will be done with hefty spark plugs and capacitors.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
We have options of a 28 VDC, 300 VDC, or 120 VAC firing system (ie, all three are operational at the test sight).

Right now I'm thinking of going with multiple ignition sources. Probably 6. Probably 12 VDC automotive systems (ie, spark plug, coil, capacitor) run at 28 VDC. The jump in voltage will obviously shorten life, but I don't think that'll be a problem given the limited duty cycles in question.

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">How will you load your ammunition? - crane? forklift?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
There should be adequate room for 2 men to work (1 on either side of the breech). I figure use a single point attachment and fork the load to them. At that point, loading is manual (2 guys ought to be able to handle a 100 pound item).

<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">And will the firing angle be set, or cranked up to variable levels by some method?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Quasi set. Some adjustment is desirable, but only a couple degrees worth. For that, I plan on just using the trailer's landing gear.
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Postby utcpyro » Wed Sep 20, 2006 1:50 am

If you use the old type oil filled coils (the cheep ones), 28V in the limited amount of time you're be applying power to them wont cause any problems.

Thinking of any small scale prototypes with proper instermentation that you could check out the exact way that the gasses combust and what type of pressure you'd be getting throughout the combustion process? I'm sure you have more toys to do that kind os stuff with then any of use have ever touched.
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Postby D_Hall » Thu Sep 21, 2006 11:19 pm

Well, the preliminary design is almost done. Still need to add more structure for recoil absorbtion and overall stabization and the fuel metering system isn't included but here's what I've got so far....
<center>
<a href="http://www.thehalls-in-bfe.com/Bender/19incher.jpg">19 incher</a></center>

'Tis breech loading with a break-type action (sort of).

Oh, and it weighs in at about 14,000 pounds (just the gun, not including the trailer).
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Postby utcpyro » Fri Sep 22, 2006 12:46 am

*drool*
So, does the mean that it's actually going to be built if you're invested the money (in your pay) into designing it and it's going to cost very little to build?

Oh, and any projections on what the power would be like? I presume INSANE my our standards, but maybe relative to the air guns you all use.
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Postby joannaardway » Fri Sep 22, 2006 4:50 am

Holy...

I knew it was going to be serious hardware, but 14,000 pounds?

That must work out at 8 to 9 tonnes with the trailer thrown in!

The fuel meter is going to be fun. At the 327 litres I guestimated before, at 90 psi, then you'd need nearly 7 metres of 4" pipe for each X of mix.

Have you ever heard hell crack open? Because if you haven't, then this might not sound that far off.

I know your work is all secret, so I guess that videos and pictures are out of the question. It would be nice to hear what it does when it's finished.
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