Stretched Estes Protostar

[Bill S]

For your viewing pleasure, here is my latest creation: a stretched version of Estes's Protostar rocket. I used a set of 1/8" plywood fins from Bad Boy Rocketry, an 18" body tube instead of the stock 16", and an longer nosecone. Overall length is 30" instead of the standard 24". The idea was to use an longer nosecone because I thought it looked better, and this way, I don't have to use any noseweight (Stability is about 1.25).

The fins are nice. They are a bit smaller than stock, but much sturdier, and they come with tabs on the ends of the fins so you can put in a slot in the fin tip pods and epoxy it all up to greatly strengthen the fin pods. I drilled 4 holes for the slot (one at each end, 2 in the middle), used an Xacto hobby saw to cut the slots, and then filed out the slot to a tight fit. Some 30 minute epoxy on the inside to hold the fin tabs in place, and voila, strong fins pods that shouldn't come off. Unlike my previous Protostar that lost a pod on nearly every launch.

I also cut off some rounded parts from the bottom of some BT-50 nosecones to glue to the bottom to seal up the fin pods and make them nicer looking.

 

[pugachu]

Looks great, I like the paint

 

[Back_at_it]

That looks really nice. I was looking at the Bad Boy fins as the slot makes a ton of sense. I've heard a lot of people having issues with the pods popping off.

 

[Bill S]

I experienced a fin pod popping off nearly every flight. Between the fin being a through the tube mount, plus the fin tip tab, plus some 30-min epoxy fillets (fin tip pod only, not the fin base), its sleek and strong. A bit heavier though, so it won't go as high (about 1100 feet with an E12 motor, but that's acceptable).

Paint is Rustoleum Custom Premium automotive lacquer spray paint, matte blue (it actually has a semi-metallic finish to it).

https://www.rustoleum.com/product-c...general-purpose-paints/premium-custom-lacquer

 

[Hobie1dog]

paint job is very nice. Thanks for the pictures.

 

[happyhaplo]

Great color on the paint, nicely done. Thanks for sharing the link.

 

[lakeroadster]

Yep... that's a thing of beauty right there. Well done. Let us know how she flies.

 

[Bill S]

Yep... that's a thing of beauty right there. Well done. Let us know how she flies.

Assuming the weather cooperates, I'll be launching it this weekend. D12-5...

 

[Bill S]

The stretched Protostar II flew yesterday, nice stable flight on an D12-5. Unfortunately, the kevlar somehow caught on one of the fin pods and hung up, causing the rocket to come down under parachute on its side. Naturally, because I seem to be cursed, it landed on an asphalt parking lot, cracking the fillet at the bottom of one fin, and scraping off the paint on the side of two fin tip pods. The paint I used takes 4-5 coats to fully cover (Rustoleum Custom Premium automotive lacquer), so just spraying several times to cover up the damaged area won't work. I had that happen to the nosecone while the rocket was under construction, and I had to sand the entire nosecone and respray the entire thing.

Design was good, flew well, got some compliments on it, crappy recovery.

 

[lakeroadster]

Congrat's. Look at the bright side... much better than a lawn dart.

An "Asphalt Seeking Rocket".... I've got one of those too. Pilots try to land on a hard surface whenever possible.

That's another advantage of a rear eject design, it helps to prevent such entanglements.

 

[Bill S]

Aw that sucketh, lakeroadster.

 

[loopy]

The stretched Protostar II flew yesterday, nice stable flight on an D12-5. Unfortunately, the kevlar somehow caught on one of the fin pods and hung up, causing the rocket to come down under parachute on its side. Naturally, because I seem to be cursed, it landed on an asphalt parking lot, cracking the fillet at the bottom of one fin, and scraping off the paint on the side of two fin tip pods. The paint I used takes 4-5 coats to fully cover (Rustoleum Custom Premium automotive lacquer), so just spraying several times to cover up the damaged area won't work. I had that happen to the nosecone while the rocket was under construction, and I had to sand the entire nosecone and respray the entire thing.

Design was good, flew well, got some compliments on it, crappy recovery.

ouch...glad it flew well, though.

 

[Bill S]

AAAAAAAAAHHHHHHH!!!! This rocket is cursed. I've only flown it twice, both times it landed on the ashpalt parking lot despite the rod being angled away. Both times its suffered damage, this time its a creased body tube right in front of the fins, and more cosmetic damage to the bottom of the pods (which is easier to just respray).

I think next time I may just say heck with it, and instead of using an D12-5 (approx 700' high), I'll bust out the E12 just so that it'll drift further away and not into that dang parking area. What's the worst that could happen, I lose it?