Lamp Crayon

[gdjsky01]

I don't know where or from whom I picked this thing up. I know I did not buy it... or did I??? Well not as Lamp!
I've had it for YEARS.
I did not really know what it was until I found the sticker inside.

I decided whilst clean some shelves to finally do something with it.

And so I figured it's about a BT-80 I.D. I had some Estes BT-80 CRs for 24mm motor mounts.

It'll need some nose weight. Some being probably 2oz.

I am not sure how much I can trust ROCSIM on the stability since the rear is modeled as a transition.

Should be fun.

Jeff

 

[qquake2k]

Everybody needs a crayon rocket!

 

[rharshberger]

Everybody needs a crayon rocket!

Or two....or 4....

 

[gdjsky01]

Everybody needs a crayon rocket!

I've had several. And still have an 'airframe' or four lying around. Around 1999 I was flying an all 'screw together' three inch crayon bank. Pink. 29mm. Clear acrylic fins. In the right light, it looked like no fins. I have them archived somewhere around here...

I've been flying crayons awhile. But this one I don't want to put fins on. Just that ass end you see.

Jeff

 

[gdjsky01]

Here ya go... I knew I had posted something...
https://www.rocketryforum.com/showthread.php?29339-Crayon-build-Posthumously&highlight=crayon

 

[qquake2k]

Looks like I need to build a crayon rocket. So you're going to use the drag from the flange on the aft end to stabilize it? I don't see why that wouldn't work.

 

[qquake2k]

Or two....or 4....

If one is good, four are better!

 

[rharshberger]

If one is good, four are better!

Actually between me and the kids we have 2 HPR Crayons, 4 MPR/LPR (under construction), and 7 LPR Estes Crayons. My kids love Crayon rockets.

As for the base ring on that lamp Crayon, it may just provide enough base drag to be stable, if not a big ring fin around the base would be cool too.

 

[gdjsky01]

Yes the idea is the conical section makes it stable. ROCKSIM likes it if I put some weight in the nose. E12s and AT 24/40s work. D12 will lob it to 150 feet. But again this assumes ROCKSIM can be trusted. And it would not surprise me if it is not a design parameter of the software to handle this case. :confused2:

I'll fly off the 'MPR' pads for the first time or two.

Similar designs like saucers fly all the time. BUT they have larger cones in proportion to the body length.

 

[BABAR]

Here ya go... I knew I had posted something...
https://www.rocketryforum.com/showthread.php?29339-Crayon-build-Posthumously&highlight=crayon

Like the crayon rocket with the plexi fins.
Really like the flip recovery to keep the fins from hitting terra firma quite so ...um... firma.

Another idea for fin protection is forward swept fins. The forward sweep loses a bit in CP management, but not much. With enough forward sweep the engine sticking out the back is usually the rocket part that takes the brunt of the initial impact.

That said, I am strictly a low power (okay, once in a while I go crazy and throw in an "E"!) guy, so dinging the end of a spent black power motor is perfect. Not sure how well a motor retained or HPR casing would handle it.

 

[Rex R]

if need be you could...mount a lamp shade on the aft end to 'cut down on the glare' from the motor .
Rex

 

[gdjsky01]

So I drilled from one side to the other in the nose cone. epoxied a piece of wood dowel from one side to the other (cutting the dowel flush with the nose cone).

Then poured 2.3 ounces (65gm) of brass BBs into the nose cone, and covered it with 15 minute System III epoxy.

Looking at it, balancing it, IF RockSim has ANY idea what it is doing, it should work!

---

Or not?

---

 

[qquake2k]

Looks good, Jeff. I've used BB's several times for nose weight. Only I used bamboo skewers instead of dowels.

 

[bradycros]

I like what your doing with this build. Keep up the good work!

 

[gdjsky01]

Thanks all...

So nice to hear from the Captain and bradycos!

Obviously this thing needs vetting out in the desert away from anyone else.
That nose cone is 2.5 ounces (71 grams) of metal. :jaw:
I could (should?) have gone for a 29mm MMT.

Lets see what happens... I go back to work Monday (yes work) after almost 4 months of unemployment.
So I have no idea what my hobby time will be like as I try and make sure I am "in the game".

 

[qquake2k]

I really need to get down to a ROC launch someday, to meet you and see some of your rockets in person!

 

[gdjsky01]

Agreed. Love to just hang out and launch with you. And Kit eta al... But the only time that makes sense given your distance and the vagaries of the weather (winds) is ROC-Stock Summer (June) or Fall (November). (Or Roc-tober I guess, which is a Sat/Sun launch focused on kids.).
It would be insane to drive to the lake bed for a day, unless you had to be down here anyway for some other reason. ROC-Stocks are Friday Afternoon to Sunday noon-ish or even a tad later. So at least you have a prayer of launching something at some point.

MDARS only has one day (more like 6 hour) launches. Same with SCRA (which really limited to G and below). Only if you had to be here to begin with. Holtville in San Diego is always a weekend launch if I am not mistaken. Never been there. Someday I should get to a TCC two day launch.

Someday I'd like to get to Springfest in Nevada. Not sure that'll happen this year with me starting a new job tomorrow morning.
The only time I am in the Sacramento area is to head to the Golden State Star Party. And never with rockets in tow.

 

[Scotty Dog]

Looking good.
Glad to see you back in action!!!
Keep up the good work.