Moving up to High Power

Morning everyone, even if it is 1:45 PM.

Just a couple real quick questions... I'm well underway with my Level 1 project, the Mad Cow DX3. Just waiting for Tower Hobbies order for more epoxy.

I noticed on YouTube that out of a bunch of Cert 1 attempts I've watched, guys have mentioned having flown their rocket (I would assume on lower power engines)
So the obvious question is can I legally fly this rocket with power below the H category of engines?

The other question I have is this: Does anyone use Monokote covering on their rockets? It's the iron-on covering used on R/C Airplanes. It's very light in weight and would certainly keep the weight down on a rocket as opposed to paint... Just curious... Thanks guys. Dave

As a general guide, you want to keep about a 5:1 thrust to weight ratio. The DX3 is likely to come in at about a pound. Even a single use Aerotech F50T is going to give you a 10:1 ratio. A single use Aerotech F20W will come in at 4.4:1, and honestly I've launched one pound rockets on them without issue before.

So, yes you'll be OK launching it on lower than H motors.

The Legal aspect of it - the FAA requires a waiver to be in place if a rocket is heavier than 3.3 pounds,or more than 125grams of propellant. It's also considered high power if the motor has an average impulse over 80N, single motor total impulse over 160 N/s, cluster over 320 N/s, or the motor is a "sparkie" propellant type.

Translated - Under 3.3 pound rocket, two G80 motors or less.

a short guide: https://www.doug79.com/stuff/HPR_metric9c.pdf

And a few quick sims for you

F20W - 913'
F42T - 784'
F50T - 1033'
G78G- 1645'
G79W- 1588'
G80T - 1923'

Those are all single use motors, requiring no hardware. Just slide them in, and fly. There are also single use high power motors.

Many people use reloadable cases for their motors. It reduces cost per flight, but requires you to build the motor. This isn't really difficult and some brands are easier than others.

I flew my level one rocket (the one in my avatar) several times on F and G motors before certing. There's really no need to do it as any kind of shakedown flight. Also no reason not to other than risk of damage. But if you've got the motor and the opportunity, I say go for it.

Diz got the rocket part covered...speaking of covered Yes, I've MonoCote'd and TrimCote'd rockets. The one I MonoCote'd I used a regular home-type iron turned way low. I use TrimCote for stripes, saves much time and hassle over painting stripes.

All of these rockets were built with Trim MonoKote.



(Below, only the one of the right)





Greg

Thank you so much to all you guys... I believe what I will do is speak with those in the club I'm joining about it, and follow their wishes so as to not get any consternation going... The R/C club that I have belonged to here in Indiana can get pretty tricky ... Somebody is always barking about the way so and so mowed the field and that sort of thing... I'm going on 67 years old and have been a member since I was 9 when my Daddy signed me up.. Like everything else, there always seems to be cross tempers, and I don't handle that very well... Greg those monokote rockets look just great... Again, thanks for the warm welcome and info from each of you... Dave

good thoughts. Lots of IN guys on this forum too.

Wait... I think you mean the 4" Super DX3, not the DX3. If you are just flying the DX3 you will be fine with a lower engine, but I think I remember in your other threads you saying it was a super. If it is a super, it's going to be more like 4 pounds and you MIGHT be able to get a flight out of a G.

I'm assuming the 2.6" cardboard version ,which does have a payload. Didn't see him say super, but I may have missed it

I've used the self stick Monokote on several rockets, both as panels and full wraps. It takes a little care in the application, but you can't complain about the results.

You won't find as much sniping in the rocketry community. Everyone just wants to burn some AP and have a good time.

Welcome to the forum Dave.

Your question on flying the rocket on other than high power motors has been answered.

I too am an R/C guy that uses Monokote for rockets. All of my cert flights (L1, L2, and L3) have been "covered" rather than painted rockets. Most people don't realize it until it is pointed out. Actually, I use Hangar 9's Ultracote. It seems to work easier and stay attached better than Monokote for me.