First-time UK Rocketeer looking for help!

[thetruemystic_]

Hey all, while I know this part of the forum is a bit like a ghost town, I thought I'd post about my current rocketry project, Plasma.

Plasma is supposed to be a simple rocket that will help me grasp the fundamentals of rocketry and UK law and its complexities.

I've been logging my process in a rocket design document which you can see here! Please note, it's still a work in progress and is getting updated as frequently as work and my masters allows me!

Any feedback is much appreciated

Please feel free to grill me for answers to problems I might encounter, I want to get this right and my fundamental understanding of things like openrocket and just rocketry in general can only get better

I'm hoping to launch at Midlands Rocketry Club if all goes well, but I have LOTS to learn until then!

Cheers

 

[Hobie1dog]

to the forum.

 

[teepot]

Welcome to the Forum. Glad to have you.

 

[thetruemystic_]

Cheers all! Not really sure on what my next steps are, I suppose starting to build it!

 

[Tim51]

Hey all, while I know this part of the forum is a bit like a ghost town, I thought I'd post about my current rocketry project, Plasma.

Plasma is supposed to be a simple rocket that will help me grasp the fundamentals of rocketry and UK law and its complexities.

I've been logging my process in a rocket design document which you can see here! Please note, it's still a work in progress and is getting updated as frequently as work and my masters allows me!

Any feedback is much appreciated

Please feel free to grill me for answers to problems I might encounter, I want to get this right and my fundamental understanding of things like openrocket and just rocketry in general can only get better

I'm hoping to launch at Midlands Rocketry Club if all goes well, but I have LOTS to learn until then!

Cheers

Welcome to the Forum. You're correct in saying not many UK rocketeers post here regularly, but alot read the forum. Good luck with your proposed flight it looks very interesting. A few points in relation to your post:
(i) UK regulations (both legal and insurance) are not that much different from US or Canada, except that 'home made' (EX) propellant is illegal. Following the United Kingdom Rocketry Association safety code will keep you the right side of the law. Midlands Rocketry Club are a UKRA affiliated club, as you may know already.
(ii) You will need to certify Level 1 to fly any H motor. I assume you know this, but if you're not certified yet speak to Paul, Kevin or one of the other MRC Range Safety Officers to arrange the exam.
(iii) You may have to revise your choice of motor. Wizard Rockets is the Aerotech dealer for the UK, and I'm not sure that they stock the H195 NT, or any SU HPR (..?) Speak to Stuart at Wizard - he will be able to advise on alternatives.

 

[LD124]

Hi!

I'm a bit of a lurker but here are some things I picked up from your presentation:

A 62-75mm airframe is very large for a first rocket. It is much more common to start with a 24mm motor and fly to a couple hundred metres, so you can launch from any reasonably sized field (with permission and a NOTAM).

H-class motors are big. Very big. As previously mentioned, you need a certification before you can even acquire one. Motors up to G are not restricted in this way, and it is advisable to start with a D or less before moving up.

An Arduino Mega is totally unsuitable as a rocket flight computer. It is designed for desktop prototyping, hence the large footprint and very numerous pin headers. Pin headers are not reliable connecters for a flight computer as they can pull out easily, especially under high-g / vibration. An Arduino Nano or similar would be much better suited. Unless you really have to build your own, there are very small lightweight altimeters that you can stick in a nosecone and will record all the data you want.

Using your own flight computer to trigger recovery in any case is no small thing. UKRA requires that you have a flight-proven COTS computer as the primary recovery device, and then you can put your own avionics in there for data logging etc. if you want. (Smaller motors e.g. up to G-class have ejection charges built-in that will deploy your parachute for you).

The MS5611 is fine, the Bosch BO055 is pricy for the sake of some code.

In summary, if your first attempt at building a rocket is a 75mm airframe powered by an H-class motor, with the recovery system reliant on an Arduino Mega with a bunch of jumper wires stuck into it:
1) no range safety officer in the country will let you fly
2) you will likely not even get to that stage as you run into all the complexities of fabricating an airframe that big and assembling your own flight computer and recovery deployment system

My advice is to start with a <50mm airframe, flying on a D motor (you can upgrade later) using the motor ejection charge for recovery, and an Arduino Nano-based flight computer in the nose to log some data.

 

[jqavins]

I'm not in a position to read the document you linked to (I'm at work) so my comments come with that caveat. Also, I'm one of those nosey, pushy yanks.

I have to agree with @LD124; it's actually rather common that people introduce themselves with grand plans, and some of use feel compelled to, gently and kindly, try to talk them into starting small and building up. Go buy a D or lower powered kit, build it per the enclosed instructions, and fly it a couple of times or more, to get your feet wet. Build an F or G powered kit to see what is different and what's not. Find OR files for the kits you build (it's almost sure that someone has them) then tinker with those to get the feel for both OR and simple rocket design. Then you can design an H-powered rocket.

Building your own flight computer is a big detour if your desired path is bigger and/or more sophisticated rockets. If the flight computer is the goal, and you just need some rockets to fly it in, that's a different story. I won't try to advise both paths here; if you state here which is your real goal then I'm sure plenty of people will have plenty more to say.