The Hairy Eyeball

[DAllen]

Okay, the sticky at the top of the featured project forum states that no project is too small so with that in mind here's mine. The vitals:

4" Diameter
7'2" long
54mm MMT
10~ pounds on the pad
K550
5300' AGL predicted
HiAlt45k
Adept22

Okay, so it's not a mach-busting, waiver-tickling or "HOLY CRAP THAT'S HUGE" kinda rocket but it's mine and it's the biggest dog-gone motor I've ever flown. I don't have a huge budget - hey, I have 2 kiddos in private school. What can I say? So this is big for me. The name originates from my daughters science teacher who is very good and quite a character. He is constantly giving kids the "Hairy Eyeball" so I thought what a great name for a rocket.

Originally flown as my L2 rocket on a J350 to only 1920'. Almost lost it in a corn field (that's an epic tale) and just recently decided it was time for a new paint job.

Can't wait!

 

[cjl]

Looks great, and the K550 is one of my favorite motors (it was also my first K motor several years ago). I love the name and paintjob too

I think your altitude estimate might be a bit pessimistic though. I flew a 4 inch BBX with about a 16 pound pad weight to 5120 on that motor, so with a 10 pound pad weight, I'd guess you're looking at more like 6-7k. I'll definitely keep an eye out for this at LDRS, though it can be hard to spot a specific 4 inch rocket among the enormous number of projects.

 

[DAllen]

Looks great, and the K550 is one of my favorite motors (it was also my first K motor several years ago). I love the name and paintjob too

I think your altitude estimate might be a bit pessimistic though. I flew a 4 inch BBX with about a 16 pound pad weight to 5120 on that motor, so with a 10 pound pad weight, I'd guess you're looking at more like 6-7k. I'll definitely keep an eye out for this at LDRS, though it can be hard to spot a specific 4 inch rocket among the enormous number of projects.

Yeah that's kinda confounding me at the moment. I switched from Rocksim to OpenRocket recently because I dropped WinXP in favor of Ubuntu so in the process of importing RS files I am not sure if OR is predicting altitudes accurately. See, if I just run the sim from the old RS file in OpenRocket it puts my L2 flight waaaaay too high (like 2600+ or something like that) so if I add mass to it to get the J350 sim to accurately match what I actually got in the field (1920') then the K550 sims to 5300' or so. My 10# weight estimate may be off though. That's just what I remember from my cert flight. Could be 10# without the motor...

I'll do some more digging to figure it out.

-Dave

 

[DAllen]

Yep...OpenRocket is predicting 5400~ feet. My dry weight without motor is roughly 10 pounds and with the K550 it's like 12.4 pounds. I think the difference is altitude cjl. You're flying in Colorado (~5500 ASL) and I am flying in Michigan (~600' ASL) and that makes a significant difference in results.

I think I got everything right in the Open Rocket file...There's only one way to find out! :roll:

View attachment TheHairyEyeball.ork

 

[cjl]

That is true - I hadn't considered the difference in air density. I still think you'll probably make more like 6k, but it should be a fun flight regardless of altitude

 

[llickteig1]

Yep...OpenRocket is predicting 5400~ feet. My dry weight without motor is roughly 10 pounds and with the K550 it's like 12.4 pounds. I think the difference is altitude cjl. You're flying in Colorado (~5500 ASL) and I am flying in Michigan (~600' ASL) and that makes a significant difference in results.

I think I got everything right in the Open Rocket file...There's only one way to find out! :roll:

Dave,

10# rocket on a K550 will certainly get my blood pumpin'. K550 is my favorite commercial reload. Great name, too.

BTW, the Rocket Pasture is about 1250'MSL.

See you soon,

--Lance.

 

[DAllen]

Aaaaand it flew on a J570. I thought I would try it out on the J first just to see how it did. Welp, it coned like crazy and I had a hard time tracking it visually so I decided not to risk it on a K. Maybe it's time to go to the eye doctor again? Anyways, it was a fun flight and I got some decent photos. It hit 3k which is about 500-600' lower than the sims show.

 

[eggplant]

Great flight! I love white lightning! Have you showed the teacher? They like that kind of stuff.

 

[DAllen]

Great flight! I love white lightning! Have you showed the teacher? They like that kind of stuff.

I'm glad you mentioned that. I just sent him the pictures this morning. He saw it about 10 days before LDRS and I did not have the paint job done...

 

[dixontj93060]

NICE! (It'll take a K).

 

[El Cheapo]

Nice pics. Love the name. It's cool yet sick and twisted at the same time. Ten pounds seems like a whole lot on a J350 to me since, once started on my L2, I'm going to try to keep mine under 3.5 loaded.

 

[jis2]

J570 not J350 , big diff. on liftoff weight!

 

[El Cheapo]

I was just commenting on the OP's L2 Cert flight on a J350.

 

[DAllen]

It did 2100' on a J350. Flew just fine. According to the numbers from Thrustcurve the thrust to weight ratio on the J350 is 8:1 which exceeds what is typically accepted as a minimum 5:1 thrust to weight ratio.

Don't worry, I did my homework on that flight long before flying it. :cyclops:

 

[El Cheapo]

Guess my post wasnt worded very well. Obviously it flew great without issues. It was just a comparison of what one does versus another. Next to how mine is designed, the Hairy Eyeball is HUGE!!!! Mine is a tuber so wont tickle any waivers either. I do have a 17% margin on the sims with a J350 so should break mach and a mile as long as I can keep the tube fins from collapsing or shredding off. These are my goals, tube fins, mach, mile on common cert motor.

Anywho, wasnt baggin or nay saying at all. Just comparing.

Back to the Hairy Eyeball.