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-   -   Scrounged-Up Designs 2006 (http://www.oldrocketforum.com/showthread.php?t=192)

CPMcGraw 05-30-2005 12:49 PM

Scrounged-Up Designs 2006
 
2 Attachment(s)
Here's a cheap-n-dirty quickie that I whipped out last night to kill off some extra components that were just laying around, otherwise minding their own business... :D

The NC came from an Estes Hi Flyer that I scavenged for the motor hook, and the BT started out as a whistle tube from the Estes Screamin' Mimi.

I call it PUG, and it uses 13mm motors. Streamer recovery.

Enjoy.


Craig McGraw

ScaleNut 05-30-2005 04:09 PM

nice !.. reminds me of the old goblin

CPMcGraw 05-30-2005 08:57 PM

New Design -- Scorpion
 
2 Attachment(s)
Here's another quickie, though not as simple as the Pug. This one is more along the lines of the Estes Interceptor and Quest Intruder.

The canopy is modeled in RS as a chunk of balsa, and should actually be more rounded than the simulation allows. This piece could also be created in clear plastic sheet, vacuum-formed. The engine intake cheeks are also shown as balsa chunks, and can probably be left this way. Again, this is a limitation of the simulator. You might choose balsa sheet to form a hollow cheek set to reduce some weight, but probably not much.

There should also be 6 simulated cooling fins attached to the motor tube, for show...

500' on a C6-5. This is the preferred motor.

Enjoy.


Craig McGraw

CPMcGraw 05-30-2005 10:18 PM

Quote:
Originally Posted by CPMcGraw
Here's another quickie...


These designs will be worked up into full PDF plan booklets, with templates and alignment guides, and possibly decal images, at a later date. When completed, they will be sent to Scott for posting to the BARCLONE website.

I'm posting them here first to let everyone have a go at them and hack on them, hopefully so you can send me some feedback on them before I get so far along with the PDFs that there's something missing.

Craig...

rkt2k1 05-30-2005 10:37 PM

1 Attachment(s)
Craig,

I like your designs! If these are "scrounged up" designs, I'd love to see your "better" designs! :D

I tweaked the Scorpion design a little to add the cooling fins you mentioned in your post. Is this what you had in mind?

... Bill

CPMcGraw 05-30-2005 11:18 PM

New Plan -- Cone Itchy Way
 
2 Attachment(s)
A "Flying Cone Of Death" design...

Don't ask about the name. It's just a play on a word that I heard somewhere and can't get out of my head!

Craig...

CPMcGraw 05-30-2005 11:28 PM

Quote:
Originally Posted by rkt2k1
Craig,

I like your designs! If these are "scrounged up" designs, I'd love to see your "better" designs! :D

I tweaked the Scorpion design a little to add the cooling fins you mentioned in your post. Is this what you had in mind?

... Bill


Thanks, Bill! I appreciate that!

Yes, this is just what I had in mind for the cooling fins.

"Scrounged Up" doesn't always mean I have the parts on hand, but this is what I'd toss together if I had them... :D

RockSIM makes it so much easier to try new designs out...

Craig...

CPMcGraw 05-31-2005 03:38 PM

New Plan -- No Tube Left Behind
 
2 Attachment(s)
Here's another truly "scrounged-up" design...

Think of a stretched "Totally Tubular"...

One plan note: The launch lug needs to be mounted on a standoff such that the rod passes through the center of one of the tube fins. The plan does not show this -- it has the rod running through the gap between the main tube and two of the tube fins. This might work, but I think it would be unnecessarily tight.

Craig...

John Brohm 05-31-2005 09:18 PM

Hi Craig;

Here's a quick way to calculate an answer to your question: if the body tubes are the same size then the space, or "void", between the tubes when they are just touching (are tangent) can be calculated from the following:

CV = 0.155BT, where CV = the diameter of the void, and BT = the OD of the body tubes.

I'd provide the full formula here except that the Forum's text window doesn't seem to permit me to cut and paste data from Equation Writer (but that's not a complaint Scott. Just an observation...).

So in the case of your tubular design, if the tubes were, say, BT-50s (OD = 0.976"), then the space between the tubes would accept a maximum diameter of 0.151"; I'd say a 1/8" rod has a good chance of sliding in there friction free so long as there wasn't too much paint build up. Saves you the lug and the drag that goes with it.



<Craig speculates:>

it has the rod running through the gap between the main tube and two of the tube fins. This might work, but I think it would be unnecessarily tight.

Ltvscout 05-31-2005 09:36 PM

Quote:
Originally Posted by John Brohm
I'd provide the full formula here except that the Forum's text window doesn't seem to permit me to cut and paste data from Equation Writer (but that's not a complaint Scott. Just an observation...).

Hmmm, I've never used Equation Writer, but I know that cut & pastes work in the text edit box. Try pasting the equation to Notepad first, then cutting it out of notepad and pasting into the forum.

John Brohm 05-31-2005 09:45 PM

Quote:
Originally Posted by Ltvscout
Hmmm, I've never used Equation Writer, but I know that cut & pastes work in the text edit box. Try pasting the equation to Notepad first, then cutting it out of notepad and pasting into the forum.


Scott;

Notepad won't accept objects from Equation Writer either; I have no problems cutting and pasting between Word documents though. I imagine the "problem" is that the elements from Equation Writer are objects, not text.

Ltvscout 05-31-2005 09:48 PM

Quote:
Originally Posted by John Brohm
Scott;

Notepad won't accept objects from Equation Writer either; I have no problems cutting and pasting between Word documents though. I imagine the "problem" is that the elements from Equation Writer are objects, not text.

Ah, yes, that could well be. Paste the equation into Photoshop then save it as a jpg and insert the image into the message. heh

CPMcGraw 05-31-2005 09:54 PM

Quote:
Originally Posted by John Brohm
Scott;

Notepad won't accept objects from Equation Writer either; I have no problems cutting and pasting between Word documents though. I imagine the "problem" is that the elements from Equation Writer are objects, not text.


John, can you "zip" the file and then send it to me via this forum as an attachment? I have a copy of OpenOffice 2.0 Beta (v1.9.104), and it has a math formula editor. Maybe I can open it from there...

Craig

John Brohm 05-31-2005 09:58 PM

1 Attachment(s)
Quote:
Originally Posted by Ltvscout
Ah, yes, that could well be. Paste the equation into Photoshop then save it as a jpg and insert the image into the message. heh


Ok Scott - good point! Must be why you make the big bucks(!).

Let's try this as an attachment. In the formula, CV is the Center Void, MMT is the Body Tube diameter (OD), and n is the number of tubes.

CPMcGraw 05-31-2005 10:31 PM

1 Attachment(s)
Quote:
Originally Posted by John Brohm
Ok Scott - good point! Must be why you make the big bucks(!).

Let's try this as an attachment. In the formula, CV is the Center Void, MMT is the Body Tube diameter (OD), and n is the number of tubes.


OpenOffice forces an additional set of square brackets around the cosine function to make it show up as purty as yours... :D

If you have a copy of OpenOffice, I've attached the file in a zip.

Did anyone ever think this forum would become THIS geeky? :eek:

Craig McGraw

CPMcGraw 05-31-2005 11:36 PM

New Plan -- Cygnus Probe
 
2 Attachment(s)
Another ST-10 design, to show support for Carl and SEMROC!

The tips of the main fins are supposed to have some 1/8" diameter dowels attached, 3.5" long, and pointed at the top. These are supposed to be the "landing legs" of this rocket, but I didn't include any feet. You could use some small circles of thick pressed paper board for this, but I'd leave them bare myself.

Attach them with 1" of the dowel ahead of the leading edge of the tip. The dowel is supposed to extend farther below the trailing edge of the fin tip, about 1.625"

Be sure to epoxy them to the fin tips, or they'll be the first to get knocked off in a bad landing...

Enjoy!


Craig McGraw

Ltvscout 06-01-2005 08:17 AM

Quote:
Originally Posted by John Brohm
Ok Scott - good point! Must be why you make the big bucks(!).

Let's try this as an attachment. In the formula, CV is the Center Void, MMT is the Body Tube diameter (OD), and n is the number of tubes.

It worked! Thanks for sending that over, John.

John Brohm 06-01-2005 07:53 PM

Quote:
Originally Posted by Ltvscout
It worked! Thanks for sending that over, John.


No problem; but watch what happens when you plug in n=6. Ain't geometry neat?

Oh and Craig, about the Geeky thing. You are aware that this is a forum mainly frequented by middling age guys still fascinated about model rockets, right? I don't think the math stuff is our biggest issue (!)

CPMcGraw 06-01-2005 08:08 PM

Quote:
Originally Posted by John Brohm
No problem; but watch what happens when you plug in n=6. Ain't geometry neat?

Oh and Craig, about the Geeky thing. You are aware that this is a forum mainly frequented by middling age guys still fascinated about model rockets, right? I don't think the math stuff is our biggest issue (!)


Touche', John. :D

My middling is a little bigger than my age, though... :eek:

Craig...

CPMcGraw 06-01-2005 08:52 PM

New Plan -- Empyria
 
2 Attachment(s)
The cheeks are balsa in the simulation, these probably should be hollowed out to reduce weight. The canopy should be rounded out, of course. Keep the tube length at 18" to eliminate having to add weight to the nose area.

Enjoy!

Craig...

CPMcGraw 06-01-2005 09:40 PM

New Plan -- Rampage
 
2 Attachment(s)
Another in the family line...

Same notations as Empyria.

Enjoy!

Craig...

CPMcGraw 06-01-2005 10:19 PM

New Plan -- Sky Marshall
 
2 Attachment(s)
For 13mm motors.

Only one motor recommended: A3-4T.

Enjoy!


Craig...

John Brohm 06-01-2005 10:29 PM

Quote:
Originally Posted by CPMcGraw
For 13mm motors.

Only one motor recommended: A3-4T.

Enjoy!


Craig...


Craig - I like this one; how would it look without the canopy?

CPMcGraw 06-01-2005 10:39 PM

2 Attachment(s)
Quote:
Originally Posted by John Brohm
Craig - I like this one; how would it look without the canopy?


Here you go, John. Not terribly bad. I might build this version myself...

Craig...

John Brohm 06-01-2005 10:42 PM

Quote:
Originally Posted by CPMcGraw
Here you go, John. Not terribly bad. I might build this version myself...

Craig...


Craig;

I've not updated my RockSim yet- two fins or three? If two, I'd be a little concerned with the sturdiness of the ring fin. Your view?

John Brohm 06-01-2005 10:52 PM

Quote:
Originally Posted by CPMcGraw
Here you go, John. Not terribly bad. I might build this version myself...

Craig...


And what do you think about bumping this one up to say a BT-50? Then you could bring in the PNC-50SP nose (Argosy, Venom), or the P/N 071005 nose (Star Rider, Nemesis). Could be slick.

CPMcGraw 06-02-2005 12:32 AM

Quote:
Originally Posted by John Brohm
Craig;

I've not updated my RockSim yet- two fins or three? If two, I'd be a little concerned with the sturdiness of the ring fin. Your view?


I chose two; The shapes of the support pylons were originally curved on the leading and trailing edges, to form the "stock" of a standard "six-shooter". If you look at the model with the fins top and bottom, the body tube was supposed to resemble a lawman's peacekeeper...

Limitations of the simulator prevented me from drawing that shape completely as I wanted...

Having said that, your comment about sturdiness is interesting. I thought about the possible vibration of the ring as I drew this up, but considered it a lesser problem given the smaller motors I intended to use. Perhaps if you add two thin, narrow pylons inside the ring toward the center, so that they're not seen in profile, maybe that would keep the ring from fluttering. Another possible solution is to glue two doublers at the ring-to-pylon joint, both sides, to reinforce the joint. Might be you could get by with two strips of cardstock, folded down the middle, and glued right into the corner on both sides, like a piece of welded angle stock...

One thing I was trying to avoid was to make it look like the Estes Sprite.

Quote:
And what do you think about bumping this one up to say a BT-50? Then you could bring in the PNC-50SP nose (Argosy, Venom), or the P/N 071005 nose (Star Rider, Nemesis). Could be slick.


Like going from a peashooter to a "Dirty Harry Magnum"? How large would the ring fin need to be to stay in proportion? I haven't looked at that yet, but I might. Interesting idea.

Craig

John Brohm 06-02-2005 08:46 PM

Quote:
Originally Posted by CPMcGraw
One thing I was trying to avoid was to make it look like the Estes Sprite.

Craig


Craig - that was my thought as well. Bringing in the 3rd fin would provide better support for the ring (a smaller propensity for flutter, not that there would necessarily be that much), but then the design conjures up the Sprite. It's what caused me to suggest bringing in those other noses that I mentioned.

CPMcGraw 06-02-2005 10:17 PM

New Plan -- Spectre
 
2 Attachment(s)
Same notes as with the Empyria...

Enjoy!

Craig

CPMcGraw 06-02-2005 11:28 PM

New Plan -- Willow
 
2 Attachment(s)
Combination ring-fin and tube-fin, using 24mm motors.

D12-3 and E9-4 are the only motors recommended. Altitudes of 319' and 515' respectively suggested by RS.

Enjoy!

Craig

A Fish Named Wallyum 06-02-2005 11:34 PM

Cool. Kind of Andromeda-esque. :cool:

CPMcGraw 06-02-2005 11:48 PM

Quote:
Originally Posted by A Fish Named Wallyum
Cool. Kind of Andromeda-esque. :cool:


And since it uses SEMROC components, you can think of it as "What Centuri might have done if Centuri had done the Andromeda..." :D

I'm learning some tricks with RS now (you can tell, right?), and some really interesting results when I put fins in various locations. I'm trying to take advantage of some of those wierd numbers in some of these new designs...

Craig...

CPMcGraw 06-03-2005 03:55 PM

New Plan -- Typhoon
 
2 Attachment(s)
One custom BMS transition required, and a long streamer, but otherwise uses SEMROC components.

The long ST-5 tube is shown in two pieces -- a 1" long inside tube and an 11" outside tube. This is a limitation of the simulator. Use one continuous 12" length of ST-5, and insert 1" up into the transition's core from the front.

Enjoy!

Craig.

rkt2k1 06-04-2005 05:57 PM

Craig,

Very cool :cool: designs!! I especially like the Willow! Thanks for sharing your designs with the rest of us!

... Bill

CPMcGraw 06-04-2005 07:53 PM

New Plan -- Cloud Tickler
 
2 Attachment(s)
This is one of my Schoolyard Sounders series...

13mm motors, ST-8 body tubes...

Designed for very small fields without making you feel like you're flying a small model...

Enjoy!

Craig

CPMcGraw 06-04-2005 07:56 PM

New Plan -- Streak
 
2 Attachment(s)
Another Schoolyard Sounder...

Enjoy!

Craig...

CPMcGraw 06-04-2005 08:22 PM

Revised Plan -- Willow
 
1 Attachment(s)
A couple of design adjustments were needed for this plan, nothing that changes the appearance or the dimensions, but which should explain what I had to do to get the plan to work on the simulator.

The connecting tunnel, between the forward crew compartment and the rear engineering section, should be a single piece of ST-5, 12" long. The two BMS custom transitions are to be cored to accept the ST-7 tube. 3" of the tube at each end are embedded through these cores, and this forms a "backbone" to keep the two sections steady. Doing this also required the addition of a BTC-5 bulkhead in the rear of the tube, to have something to mount the screw eye into. EPOXY the screw eye into the bulkhead, and EPOXY the bulkhead into the tube.

The BR-1013 transition should also be cored, with a 1.75" length of ST-5 embedded as a liner for the deployment gasses to pass through.

Hope this clears up any confusion...


Craig.

CPMcGraw 06-04-2005 08:30 PM

Quote:
Originally Posted by rkt2k1
Craig,

Very cool :cool: designs!! I especially like the Willow! Thanks for sharing your designs with the rest of us!

... Bill


Thanks for the kind words. I'm happy that folks are liking what I've come up with.

Be sure to download the updated plan for the Willow, because I made a couple of changes that should make the plan more understandable. Read the comments section "hidden" on the first tab of the simulation file. The simulator has a few limitations in what it understands about construction, and I've had to adapt my thinking around it.

Craig...

CPMcGraw 06-05-2005 07:42 AM

New Plan -- Solar Flare
 
2 Attachment(s)
Another in the Schoolyard Sounders series.

Schoolyard Sounders are all 13mm motor designs, intended for flying in small fields and small schoolyards, but without compromising the size and feel of larger 18mm designs. These designs offer great performance with minimal power.

Enjoy!

Craig McGraw

CPMcGraw 06-05-2005 07:49 AM

New Plan -- Pointy Thang
 
2 Attachment(s)
When Flying Cones Of Death develop attitudes, they often look painful just standing still...

The simulator says this will fly, and not too shabbily, either.

Enjoy...with care!


Craig...


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