Level 1 motors

I have a question specifically for UK members regarding level 1 motors.

I'm planning to attempt level 1 sometime soon. I have the rocket and have tested it successfully on a G motor.

I'm now deciding on the H motor to power my attempt. In line with the design I have a choice of a Cesaroni 29mm/3G/H90 or H163. Either will do, I'm in favour of the 163.
My question is: Is there any restriction in the UK on the type of H motor I can use for a level 1 attempt? As far as I can read, it only has to be an H motor. The type is not is not a factor. Is this correct?

Belt and braces checking maybe, but I want to be sure I haven't missed any small clauses in the rules.

Advice appreciated.

SO.

Following with interest, have just ordered my own 29Pro with similar thoughts. As I interpret the motor classes an H163 supplies 49lb peak thrust compared with 35lb for the H90. Quicker off the rod?

You are correct Space Oddity.

You can use any legally obtainable solid fuel H class motor, which includes the Cesaroni Pro29 motors.

JohnRE,

You are correct about the difference between the H90 and H163, they are very close in total impulse so will probably go to approximately the same height and maximum velocity, but the H163 will burn in just over half the time of the H90 so will be much faster off the rod or rail.

Thanks for the advice.

Interestingly the OR design suggests an altitude difference of only 5 feet at around 1800.

The launch rod velocity is 15mph greater with the H163.

The biggest difference is in the maximum acceleration and velocity figures which are both much greater with the H163. I think the rocket is built to survive both (I hope).

Now for the deciding difference between the two motors. An H90 costs 20p more than the H163!

SO.

PS. I'll let you know how the flight goes which should be in May or June and should be a quickly long reported success or a furtively and short reported, "back to the drawing board" disaster.

My personal preference would be the H90, mainly because of it's longer burn time. With the H163 it's blink and it's gone with the burn time of a second.

The following is just a bit of fun.

The H90 may be more expensive, but if you calculate the cost to burn rate it works out better value.
Looking at the prices, I see the H90 costs £20.99, and the H163 £19.99.
So the cost per second of burning those motors is:
H163 = £19.99 / 1.02 = £19.59 per second
H90 = £20.99 / 1.82 = £11.53 per second

So it just depends really on how fast you want to see your money go up in smoke (literally)

Don't want to thread-jack but is one able to purchase an H rated motor ahead of a certification flight or does it need to acquired on the day from an L1 or above? As things stand I doubt I will be launching for some time, nor will the lauch be local, nowhere to fly so high with a decent chance of recovery, but it never hurts to clear stuff up early. I am assuming E, F & G is fine (if you have a large enough flying area).

If you have an RCA from the HSE you can purchase and store E, F G and H class motors, actually you can go up to J class. As I said before, obtaining an RCA is as simple as sending the pre-prepared letter to the HSE.

JohnRE said:

Don't want to thread-jack but is one able to purchase an H rated motor ahead of a certification flight or does it need to acquired on the day from an L1 or above? As things stand I doubt I will be launching for some time, nor will the lauch be local, nowhere to fly so high with a decent chance of recovery, but it never hurts to clear stuff up early. I am assuming E, F & G is fine (if you have a large enough flying area).

Click to expand...

No "thread jack" at all. In fact I'd meant to ask the same question. However, having now used a Cesaroni G motor I'm happy to buy an H at the event rather than in advance.
Before I bought my first motor all I knew was from what I'd read on web sites and from a down loaded manual on the Cesaroni site. Buying one in advance of a flight was very helpful for a first time user like me. To be able to take it apart and understand it with my fingers rather than from pictures on a web site, that was invaluable. In the event I missed something, how to install the igniter. Though I read the instructions they didn't register where that was concerned. Fortunately there were many on hand at the event to tell me that all I had to do was bend the igniter into a loop before closing it into the retainer cap - obvious really!
I guess that my point is that for beginners it's rarely obvious, there are always questions that seem stupid to ask on here. But they are worth asking. Once you've done it once it becomes second nature immediately and you wonder why you worried about in the first place. I suppose that learning and doing it confidently is all part of the fun.

Speaking of fun, Simon; I bow to your ability to to take costs and highlight them in a positive way. Are you an accountant by any chance? ��
I have to say that my view of level 1 is to get the rocket up and back as quickly as possible, relieve the tension, and get the bit of paper. Then I can relax, experiment and launch H's and I's with purpose and adventure.

But seriously and without consideration of cost I think you maybe right. The H90 Is probably the best bet. I'll go for that. As I've said somewhere before, for level 1 (or for that matter any level qualification) I want the least spectacular flight possible. I'll save the spectacle for the next flight.


SO.

Simon, letter found, edited and off in the epost. Thanks for the pointers via your email.