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18mm
Fat Boy XL
- Thread starter DragonRocketry
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Just finished mine. Only ended up adding maybe half the nose weight, should be plenty stable. Won't be able to fly it until next month. Clearcoat just went on, so now it's just a waiting game. Super sturdy build. Since its so wide, was able to do nice inside fillets and then some expanding 2 part foam just for fun.
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Ordered March 21, finished April 20. I love it.
happyhaplo
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If they had any of these in stock I would have purchased one, I ordered a big daddy with upgrades instead.
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I will have more as soon as my supplier gets more 4" tubing in. Right now, it is looking like it will not be till after the beginning of May.
Did you contact the vendor and ask about inventory before losing your patience and posting something retaliatory?
happyhaplo
Member
Retaliatory to state something was out of stock? Sorry I dont think it was negative at all. And no I did not contact the vendor to confirm that their website was accurate when it said it was out of stock. As you can see above your post Dragon has stated why and when they will be back in inventory.
happyhaplo
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That's perfect timing as ill have another payday before then. Thanks for the heads up.
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Anyone wanting one, I have 2 38mm versions in stock. This will be the last till I get a tubing order in sometime in the beginning of May.
Sooner Boomer
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When do we get the version with a 54mm motor mount? I'm debating flying mine on a 38/360 H999N-P. I fear it will shred.
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5.5" version with a 54mm motor mount?
Sooner Boomer
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4" or 5.5" I can probably overpower either...
Tip to tip fg!
Sooner Boomer
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Not worried about fins. I'm worried that the centering rings won't hold up to the predicted 200+ Gs of acceleration.
Yeah, I was thinking of those too (runaway motor!), but you can fg & epoxy the heck out of the motor section as well (for my 7.5 V2 I'll likely do that). Fg inside & out, but also don't forget a tracker...AND video!
However, it would then probably make more sense to just get it in all fg, but what's the fun in that?
Actually I thought about it a bit more. I have a 4" phenolic and plywood Madcow Patriot that has over a pound of nose weight and it was fine off an I600.
Given that, I'd guess
the FBXL motor section should be able to take the H999 assuming strong fillets inside and out since there isn't much static mass for the motor to fight against to accelerate off the pad. However, once it gets up, the next question is if the fins (and rocket) can survive 500mph+ speeds.
YMMV since I don't have experience in this scenario, but I'll cheer on any of your efforts to do so!
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Build the fin can outside the body tube. Set you bottom CR on the motor tube, then epoxy your fins the motor tube. Then put the top ring on tight to the fins. Then use some fiberglass strips and glass the fin roots to the motor tube This will be more than strong enough to handle that motor.
Here's a great thread on similar Big Daddy (with some upscale Fat Boys) on some BIG motors. Great reading!
https://www.rocketryforum.com/threads/anyone-flown-an-estes-big-daddy-on-38mm-hardware.155387/
And from what I recall in other threads with short rockets like these, as the motor gets longer, the less nose weight needed since it starts to extend past the CG!
(YMMV)
Sooner Boomer
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None of the loads for an Aerotech 38/360 will lift the rocket to over 2000' (by sim). I don't think I'll need a tracker.Yeah, I was thinking of those too (runaway motor!), but you can fg & epoxy the heck out of the motor section as well (for my 7.5 V2 I'll likely do that). Fg inside & out, but also don't forget a tracker...AND video!
However, it would then probably make more sense to just get it in all fg, but what's the fun in that?
Ya got me thinking...
I'm now tempted to build three Fatties... XLite, XL Stock-y, and XL Heavy (38mm).
However my sim puts the H999 over 3K. Plus that's a warp motor, so it's plugged and needs an altimeter for deployment. Will think about it, but I gotta build the other two first!
Sooner Boomer
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If you do the 7.5” version and will ship it to Australia, I’ll buy one!
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A little update to the Fat Boy XL kit. All kits from this point on will be 38mm and a 29mm adapter will be included, also the nose cone now has a removeable bulkhead so you can adjust the nose weight or hide a tracker in there. I will also be offering a night glow version that will have a LED lighted nose cone. Should have more of these in a week or so as I finally could order some more tubing as my supplier got their order in today.
Thank you all for your support.
Thank you all for your support.
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I made a 38 mm big daddy and put an H550 in it - was out of sight so quickly, good thing I had GPS in it. Found it half a mile away not a scratch on it. I purposefully got the 29 mm version of the big daddy so I could fly it from our low/mid power pads. Inaugural flight was on a G76 and it was perfect! Such a perfectly straight flight, it actually started to tail slide back down after apogee before the chute popped. Maybe an H238 next...
Aww, fatty catty. He looks pissed that you brought out the scale...again. LOL
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He probably can't see the scale very well. His eyes are almost completely black. He can see, but we think the right eye is blind and the left eye is less-than-optimal.
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Finally got to fly mine. Fantastic perfectly straight flight on an Aerotech G138T!
ljwilley
I’m pretty sure it will work…
Yes he does. I bought a nose from him a few months ago for a 3" dia. Starship Vega upscale. I think he can do it any size, if he glues together enough pieces, but it would be INSANELEY expensive. The 3" dia. nose I got cost the same as the entire Fat Boy XL kit itself! I can't imagine how much a 7.5" kit would cost! Again, about size, he has pics of noses on his site of rocket noses he made that were at LEAST 7.5"
P.S., I vote 98mm motor mount!
