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  #31  
Old 05-12-2005, 07:46 PM
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Quote:
Originally Posted by Nuke Rocketeer
Cherokee triple C-triple D.


Sounds like one of Doug's cartoon women.
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  #32  
Old 05-12-2005, 08:20 PM
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Quote:
Originally Posted by Eagle3
I'll weight the cam and a 9V battery tonight. It's not going to be a lot. The cam weighs less than the battery IIRC.


9V Battery = 46.6gm
Cam and wire harness = 19.2gm

Total = 65.8gm or 2.3 ounces

Add maybe another 25grams for the mounting bay..... yes... yes.... this is most doable.
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  #33  
Old 05-12-2005, 09:49 PM
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Quote:
Originally Posted by Eagle3
9V Battery = 46.6gm
Cam and wire harness = 19.2gm

Total = 65.8gm or 2.3 ounces

Add maybe another 25grams for the mounting bay..... yes... yes.... this is most doable.


So, maybe allow about 3.25 oz for the full package, including padding and "sloppy construction"...

Here's the results:

For the Double-D, we get 1654'.

For the Triple-D, we get 2283'.

In all of the simulations, with and without the camera package, I've averaged about 600' higher with the Triple-D. That's a farily good difference for the difference in power of one D12 motor.

Yes, I think this is a do-able project. I may have to break down and order a camera package myself just for this.


Craig...
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  #34  
Old 05-12-2005, 10:23 PM
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Quote:
Originally Posted by Ltvscout
Kind of funny how this design is the exact opposite of how Centuri and Estes use to design their multi-stage rockets. There designs always had the booster with the larger fins.


It is strange, isn't it? The formulas we use and the ones they used back then are basically the same. I guess that's the advantage we enjoy of having GUI-based computer tools like RockSim over what the pioneers in this hobby had, which was pencil and slide rule.

We're able to try out various design ideas and SEE what happens before the model ever gets built, which means we can change things faster and try again before the glue could dry on a fin. It could also be that we're willing to attempt odd-ball things more than designers were back in the 50's and 60's because the tools allow it. Designs like the Farside and the T-Bird reflect a more traditional, subdued, dare I say "conservative" approach to engineering. Pencils and slide rules allowed a measure of "what if?", but not to the same degree as our fast desktop computers with full-tilt simulators. Imagine if the Apollo engineers had access to a copy of RockSim 8 with just a "simple" eMachine to run it on? We might be sitting in our home offices on Mars reading these messages tonight...

I'm just trying to show my appreciation by using these tools as often as I can!

Craig...
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  #35  
Old 05-12-2005, 10:30 PM
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I took my kids out to eat at a Max & Erma's last night while my wife was out with some friends. The Max & Erma's in Eastgate has a giant. and I mean GIANT, slide rule hanging on the wall as a decoration. I don't know of anything locally significant that it would be there for, so I guess it's just a M & E warehouse thing.
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  #36  
Old 05-12-2005, 10:35 PM
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Quote:
Originally Posted by Nuke Rocketeer
How about adding three strap-ons using C6-0's to the first stage? That ought to add a few feet in altitude! Hmmmm........Cherokee triple C-triple D. I just may have to build this.


Yikes! What kind of a monster have I created here?

I think the biggest issue here is in the timing of the motors. The C6 burns 0.25 seconds LONGER than a D12, so there would still be residual thrust from the strap-ons when the second stage ignites. The strap-ons would still be "strapped on" at staging. Also, this setup requires the D12 to be lit 0.15 seconds AHEAD of the three C6s to achieve a peak thrust at the same moment. That means a complicated launch system with separate feed circuits, and all four motors MUST fire, without a failure.

Not impossible, but not simple, either!

Something to consider for a later project...

Craig...
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  #37  
Old 05-12-2005, 10:45 PM
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Originally Posted by CPMcGraw
... there would still be residual thrust from the strap-ons when the second stage ignites...


And as fast as I typed this in, another possibility came to me in that it doesn't really matter when the C6s 'shut down'. The act of booster separation could simply "release" the three strap-ons simultaneously, thus negating the residual effect of the extra thrust. The thrust from the three strap-ons would "die" at the same moment as the booster itself.

The added visual effect of the three strap-ons "peeling away" like from a Delta would also be"veer-ry een-ter-resting"...


Craig...
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  #38  
Old 05-12-2005, 10:50 PM
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Quote:
Originally Posted by A Fish Named Wallyum
I took my kids out to eat at a Max & Erma's last night while my wife was out with some friends. The Max & Erma's in Eastgate has a giant. and I mean GIANT, slide rule hanging on the wall as a decoration. I don't know of anything locally significant that it would be there for, so I guess it's just a M & E warehouse thing.


Is M&E a chain, or just a local shop? What kind of grub-n-grog does it sling?

Maybe what it needs is a model of the SatV hanging next to that slide rule...

Or, less expensively, perhaps, a model of a Cherokee Triple-D???

Craig "Eating is NOT against my religion!" McGraw
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  #39  
Old 05-12-2005, 11:30 PM
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Quote:
Originally Posted by CPMcGraw
...this setup requires the D12 to be lit 0.15 seconds AHEAD of the three C6s to achieve a peak thrust at the same moment...


Another layer of proof that the human brain doesn't work after midnight...

Or even after 11 PM...

When I overlayed the C6 graph over the D12 graph, what I get is a 'double spike', or a two-tiered thrust curve, where the peak thrust of the combined C6s begins to decay before the D12 has come up to full chamber pressure. Essentially, the three C6s would be the dominant force lifting the rocket, although the D12 would contribute signifigantly to the overall effect. The three C6s also have greater residual thrust than the D12...

Three D12s plus three C6s also peg the limit on fuel at 3.96 oz of powder for the combined all-up stack...

So, as long as ALL FOUR motors ignite AT THE SAME TIME, this would be one impressive bird. Going to need a couple of gel-cells, or a really fresh deep-cycle truck battery on a relay-driven launch system with VERY reliable igniters to achieve this level of reliability. Anything short of perfection might cause a few folks to need a change of underware...

Craig...
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  #40  
Old 05-13-2005, 01:32 AM
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Quote:
Originally Posted by CPMcGraw
Is M&E a chain, or just a local shop? What kind of grub-n-grog does it sling?

Maybe what it needs is a model of the SatV hanging next to that slide rule...

Or, less expensively, perhaps, a model of a Cherokee Triple-D???

Craig "Eating is NOT against my religion!" McGraw


Yes, it's a chain. The particular one we ate in the other night was pretty bad, and it's fairly new. They're kind of a rung or so down from Applebees, O'Charleys or TGIF. Not quite as expansive a menu as those three, but a little more than a Steak & Shake. We probably won't go back based on this past visit. I should have gone with Sonic. Longer drive, but cheaper and better food.
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