Do you consider MPR a pre-requisite for HPR?

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Off Grid Gecko

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I couldn't think of a clever title that encapsulated what I really want to ask, but I've been thinking on this lately.
First, this thread is not to demean, undermine, or discourage using MPR as a stepping stone to larger rockets. I'm simply seeking some concrete clarification and different people's opinions on the matter. That said.
I see it quoted quite often that experience should be gained in a hierarchical order. Generally LPR first, then "stepping up" to mid power, then onto L1 and L2, each in their own category. I won't discuss L3 here.
I see the merit in someone new to rocketry starting with low-power kits. I think a lot of us started there as kids, or even as adults. There's a lot to rocketry, and the LPR stuff offers a low barrier to entry, both in terms of cost and difficulty. It's an "easy" way to get familiar with rocketry, you can fly just about anywhere, and unless you live near an airstrip there is no need to call the FAA or the closest tower.
High power is obviously a different animal. I can Elmer's glue a LPR rocket from paper in a matter of hours and it will fly just fine. Obviously we don't want that kind of construction mentality when dealing with 10-s to 100-s of pounds of thrust, or higher as the scale progresses.
Now, MPR is in the middle. I know I had a kit or two that flew on D's and E's as a kid, just fell out before I got to them "big" F motors that I would drool over. They do need to be constructed with some minimal amount of care, but for the most part, they mimic the smaller LPR build process with a touch more attention to detail. Let me stop there for a minute.

So, not looking for anyone to argue with anyone else, just your own opinions on this. Should MPR find it's way into everyone's fleet before considering a high-power build at all? Why? Why not?
Some of the why's that I can think of quickly:
-More familiar with stronger building techniques
-More time to learn about bond strength and think about how much stress is applied to a rocket in different places.
-Fly a little higher and cement the idea that you need more space with more power.
-Failures are lower risk than with HPR (though things can still fail even with a careful build)

And finally, I don't see MPR as a "requirement" so much. I see it as a stepping stone. People come to our hobby from engineering disciplines sometimes, sometimes they are already expert model builders. Some have flown RC helis or race RC cars and understand a lot of concepts the average guy off the street wouldn't. Etc. Some people read a lot more than others (how many people visit this forum frequently to learn what they need to know without ever signing up?)
To me this is more of a case-by-case thing. To my brother I recommended him to get a little launch rod and a small kit. He knows how glue works and has built models before. I also recommended going with a small motor and explained how easily these things can get lost. And he did this as a kid at one point as well. But getting back into the hobby, it's the easiest way. I might also recommend MPR to him if he wants to go further so that he can learn some of the engineering concepts specific to rocketry.
But I don't consider these recommendations a one-size-fits-all solution. Someone who understands engineering and has built and flown several small rockets on C and D engines probably has the basics down, and might select more appropriate glue, but otherwise could be turned loose on a bigger build, especially if they are simulating all of their designs on the computer already.

Just some thoughts, sorry so long winded. What are your thoughts? To restate the general question, do you consider MPR a pre-requisite for HPR?
 

mikec

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Not a prerequisite, but it's much cheaper and a lot of the experience at least at the F/G level translates directly to HPR. Certainly flying MPR for a while directly contributed to my success in my L1 and L2 cert flights.
 

dhbarr

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Barely anything's mandatory and some people grouse about even that.

But g54fj's, g64w's, and g76g's are relatively inexpensive ways to have no-hazmat no-waiver fun, right up to the FAR101 limits.
 

Off Grid Gecko

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I consider it a nice addition to experience, but not requisite.
I wonder if you could elaborate or "put a pin on it," the experience that you see someone gaining from MPR, as it's this point that I'm most curious to hear people's opinions, and yours I greatly value.
Do you think it's build quality/strength experience?
More flying time, and likely more time at club launches as not many can scoot a rocket so high from the local park? So, experience with a club environment?
More launches = better knack for knowing how the wind and parachute sizes will affect certain builds?
etc.
 

Off Grid Gecko

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Not a prerequisite, but it's much cheaper and a lot of the experience at least at the F/G level translates directly to HPR. Certainly flying MPR for a while directly contributed to my success in my L1 and L2 cert flights.
G and H aren't that far apart indeed. Could you give some examples of precisely what you learned from MPR that helped you on your L1 and L2? Did you test out dual deploy on MPR? (I'm planning on doing this) I'm genuinely curious and I think your experience might be perfect for this thread.
 

mikec

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Could you give some examples of precisely what you learned from MPR that helped you on your L1 and L2?
I built a couple of MPR rockets (2.6" Madcow kits) that are much more like HPR rockets than small Estes kits (plywood, TTW, epoxy) and in fact would be perfectly fine L1 rockets. Then I built my L1/L2 rocket (Madcow Super DX3) and flew it several times on G motors. After that, a flight on an H123 was not much of an increment.
Did you test out dual deploy on MPR?
I actually didn't, though there is nothing wrong with doing this (I've done it a lot subsequently, a 38mm DD rocket on a G is a nice fun flight). I ended up doing my L2 with motor ejection and no electronics, and the rocket gods decided to keep the winds aloft low. With an apogee of nearly 4000 feet it's not something I would recommend.
 

Antares JS

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I don't think it's something you need to get into extensively, but building and flying a mid-power kit or two can give you some experience working with epoxy and assembling reloadable motors - both valuable skills that can contribute to a successful high power cert. Nowadays you can also experiment with electronics and dual-deploy with a kit like the LOC Deployer.
 

Off Grid Gecko

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I don't think it's something you need to get into extensively, but building and flying a mid-power kit or two can give you some experience working with epoxy and assembling reloadable motors - both valuable skills that can contribute to a successful high power cert. Nowadays you can also experiment with electronics and dual-deploy with a kit like the LOC Deployer.
I had forgotten all about motor assembly, especially if you plan on running Aerotek hardware. I'm going with CTI on my L1 just to keep everything as "dummy proof" as possible :p
 

Nytrunner

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First thing to note is that "Mid power" doesnt really exist. There are Model rocket motors (mmax-G), High power motors (H-O), and experimental amateur motors (P+).

The mid power distinction is really home grown out of the hobby itself. When you get to Es, Fs, and Gs, you start to get some real altitude and lifting power. The composite motors that are available starting in those classes can teach about impulse and burn time differences as well as motor building. More thought should be put into the rockets and their flights than "make tube fly with FIre!"

I once thought E didnt really belong in "mid power" because my only experience was with the Estes E9, but there are some kicker composite E's out there and I understand better now. (And even the E9 can lose slick rockete)

-Fly a little higher and cement the idea that you need more space with more power.
This is the most important reason in my opinion. You can punch pretty average rockets over a quarter or half mile with F's and G's, gaining valuable flight and recovery experience without having to wait for waivered launches or be certified. What I tell folks interested in high power is that if you can fly and recover a G, L1 is a walk in the park. (For most cases anyway, there's a bit more to learn for the I1299)

I also happened to use mid power rockets to experiment with electronic deployment and tracking without needing a waiver, and without having to cram stuff into a D powered airframe. Strength building is relative. My L2 was mainly woodglued except for where plastic or metal parts were bonded

But I don't consider these recommendations a one-size-fits-all solution.
That is the key. All powers of rockets have there place. Whether for learning, or flying economically, or however they make folks enjoy the hobby.
 

heada

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Take an Estes Star Orbiter, load it up with a CTI G33 and a BT60 electronics bay from Apogee and a Quark from Eggtimer. All that is mid-power but uses skills that aren't required until well into HPR. That rocket on a G33 will be out of sight to all but the best of eyes when it hits apogee.

If you roll your own CF tubes and go minimum diameter, get an Apogee F10 and break a mile high easily.

Mid power isn't required but teaches the skills needed for high power. Vast difference in build methods for a low end G vs a high end H.
 

OverTheTop

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Not entirely a prerequisite, but it develops some nice skills as people have mentioned. It is also nice to go back to some smaller rockets as they are so easy to prep and fly. Low-stress rocketry!

They are also good to fly if the cloud ceiling is sitting a bit lower than you would need for HPR.

Forgot to mention, they are a lot easier to transport too ;).
 

scschulte

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Excellent question. I really think that like learning a language, progression from basic rockets (or vocabulary) to more complex and often more powerful rockets is a logical path to take-- and fun, too! Many things can be tested on small model rockets-- and often the skill required to build a smaller rocket (from sanding balsa wood to attaching parts inside a 0.75" diameter tube…) is higher than with the larger diameter rockets. (I love 4" diameter rockets because my arm fits down the entire length!). Having built rockets since 1962, in retirement now I am working (eventually) on my Tripoli Level-3, but just built a 9" tall, 1 oz. "Full Moon" kit and I can tell you it honed my sanding, glueing and painting skills! And the cost is generally much lower for MPR -- which lets one experiment a bit!

So YES I would say LPR, MPR then HPR level 1, 2 and perhaps 3 --- but also go back and build different models. One example of HPR helping with LPR - I modify kits to include high-strength Nylon or Kevlar® shock cords -- no more elastic unless we're talking 3 oz models or under.

I'm new to this Rocketry Forum and looking forward to participating. And I'll be having lots of questions on dual deployment and more!

Thanks for posting and stay safe!

Steve Schulte
Tuesday 7 July 2020
 

OZRoc

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As far as I'm concerned MPR is a definite step to HPR. The skills required to enjoy the transition from LPR to HPR are a much required progression.
As a BAR with a 20 year hiatus before coming back into the hobby I (re)found the skills necessary to continue on through the system and was (am) very thankfull I did so. The progress through MPR to HPR (IMHO) is a pre-requisite for all the disciplines necessary to move on. As that BAR with a founding in approx. 1965 I am only now attempting L3 because only now I am happy with myself to do so.
LPR - MPR - HPR. Necessary steps.
Cheers,
Mark
 

Greg Furtman

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I have been flying LPRs since high school (I graduated in 1969.) A few years ago I was asked to mentor a HPR college team for the First Nations Launch Competition at the Tribal College I worked at. It was my first introduction the HPR. The Wisconsin Space Grant Consortium, who sponsors and funds the FNL came to our College and held a workshop where each team member, including myself, built a LOC Caliber-ISP, a 3.1" rocket with a 38mm motor mount. The building workshop was 2 days long. On the 3rd day we launched them at a local HPR field thanks to the support of the Western Wisconsin Association of Rocketry and we recovered all of the rockets in flyable condition. And for that we all received our Tripoli Level I certificate.

I modded my Caliber-ISP to be a dual deployment rocket and have flown it with the WWAR group a number of times. Nothing like a HPR launch. But it is expensive and now that I'm retired money is tighter. So now I am messing around with MPR. Less expensive to fly but I still have many motor choices with 24mm and 29mm motors.

So yes, you can go from LPR to HPR if you have some guidance with no difficulty.

WGR_0418.JPG
 

Steve Shannon

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I wonder if you could elaborate or "put a pin on it," the experience that you see someone gaining from MPR, as it's this point that I'm most curious to hear people's opinions, and yours I greatly value.
Do you think it's build quality/strength experience?
More flying time, and likely more time at club launches as not many can scoot a rocket so high from the local park? So, experience with a club environment?
More launches = better knack for knowing how the wind and parachute sizes will affect certain builds?
etc.
Sorry I didn’t elaborate.
The simple fact is that I went straight from D to H without ever flying anything in between, so obviously the experience of building and flying MPR wasn’t truly necessary. I never even saw a G motor until the day before I certified L1. In fact I might not have flown a G until after I was L3. That doesn’t say anything good or bad; I was just enjoying HPR.
At that time there was an official definition “large model rocket” which the FAA used. Up to and including a pound was a model rocket. Above a pound but less than 3.3 pounds were the “large model rockets” which required notification but not permission. Above 3.3 pounds was high power rocketry, which required permission before flying. I don’t remember if impulse levels were part of the differentiation between model rockets and large model rockets. Since then the FAA has changed to the Class 1 - Class 3 system which considers mass (only at the boundary between 1 and 2) and impulse and lumps mid power into Class 1 along with model rockets.
The reason I believe that experience with MPR is beneficial is because midpower rockets can be flown without a COA yet have enough impulse to lift rockets which use more advanced building techniques, such as laminating fiberglass to cardboard tubes, dual deployment recovery, and the use of composite materials or polymers such as Quantum tube. Bridging the gap in impulse also can add to a rocketeer’s confidence; many, if not most, midpower rockets could be used to certify with a small H.
 

Mike Haberer

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I had forgotten all about motor assembly, especially if you plan on running Aerotek hardware. I'm going with CTI on my L1 just to keep everything as "dummy proof" as possible :p
I would recommend an Aerotech DMS for an L1 flight. Eliminating the engine assembly limits variables. All you have to do is drill the delay. There are plenty of H DMS engines to choose from.
 

boatgeek

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I had forgotten all about motor assembly, especially if you plan on running Aerotek hardware. I'm going with CTI on my L1 just to keep everything as "dummy proof" as possible :p
I'm a CTI partisan too, so I approve this message. Aerotech DMS motors are also excellent choices, though there's not as much variety as the CTI 3-grain and 4-grain 29mm motors.

My personal experience was also largely skipping MPR. After returning to rocketry 20 years after my last launch in 4th grade, I watched my older kid's TARC team and built/flew an Estes Wizard. That became frustrating quickly, popping fins on nearly every flight and then losing the rocket on a C. At that time, I was getting more involved in the TARC team and decided that I should build an L1 bird so that I had more experience to give the team technical advice. I also went scratch because I prefer scratch builds to kits. Cheeto Dust flew once on a G88 before getting my cert (I didn't really realize I wasn't supposed to fly that motor without an L1). After fixing the retention that I broke on that flight, it flew successfully on its next flight. Since then, I've flown that rocket more on MPR motors than HPR, but that's partly because of the fields we have readily available. So the MPR experience wasn't really all that important to me getting the cert.

However, I came from a place of some experience in building with epoxy and plywood from building and repairing boats, so I didn't really need to build those skills. I also learned an awful lot about construction on that project, which made my later HPR builds far better.
 

jrap330

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I couldn't think of a clever title that encapsulated what I really want to ask, but I've been thinking on this lately.
First, this thread is not to demean, undermine, or discourage using MPR as a stepping stone to larger rockets. I'm simply seeking some concrete clarification and different people's opinions on the matter. That said.
I see it quoted quite often that experience should be gained in a hierarchical order. Generally LPR first, then "stepping up" to mid power, then onto L1 and L2, each in their own category. I won't discuss L3 here.
I see the merit in someone new to rocketry starting with low-power kits. I think a lot of us started there as kids, or even as adults. There's a lot to rocketry, and the LPR stuff offers a low barrier to entry, both in terms of cost and difficulty. It's an "easy" way to get familiar with rocketry, you can fly just about anywhere, and unless you live near an airstrip there is no need to call the FAA or the closest tower.
High power is obviously a different animal. I can Elmer's glue a LPR rocket from paper in a matter of hours and it will fly just fine. Obviously we don't want that kind of construction mentality when dealing with 10-s to 100-s of pounds of thrust, or higher as the scale progresses.
Now, MPR is in the middle. I know I had a kit or two that flew on D's and E's as a kid, just fell out before I got to them "big" F motors that I would drool over. They do need to be constructed with some minimal amount of care, but for the most part, they mimic the smaller LPR build process with a touch more attention to detail. Let me stop there for a minute.

So, not looking for anyone to argue with anyone else, just your own opinions on this. Should MPR find it's way into everyone's fleet before considering a high-power build at all? Why? Why not?
Some of the why's that I can think of quickly:
-More familiar with stronger building techniques
-More time to learn about bond strength and think about how much stress is applied to a rocket in different places.
-Fly a little higher and cement the idea that you need more space with more power.
-Failures are lower risk than with HPR (though things can still fail even with a careful build)

And finally, I don't see MPR as a "requirement" so much. I see it as a stepping stone. People come to our hobby from engineering disciplines sometimes, sometimes they are already expert model builders. Some have flown RC helis or race RC cars and understand a lot of concepts the average guy off the street wouldn't. Etc. Some people read a lot more than others (how many people visit this forum frequently to learn what they need to know without ever signing up?)
To me this is more of a case-by-case thing. To my brother I recommended him to get a little launch rod and a small kit. He knows how glue works and has built models before. I also recommended going with a small motor and explained how easily these things can get lost. And he did this as a kid at one point as well. But getting back into the hobby, it's the easiest way. I might also recommend MPR to him if he wants to go further so that he can learn some of the engineering concepts specific to rocketry.
But I don't consider these recommendations a one-size-fits-all solution. Someone who understands engineering and has built and flown several small rockets on C and D engines probably has the basics down, and might select more appropriate glue, but otherwise could be turned loose on a bigger build, especially if they are simulating all of their designs on the computer already.

Just some thoughts, sorry so long winded. What are your thoughts? To restate the general question, do you consider MPR a pre-requisite for HPR?
I believe in going in steps for all the reasons you stated and in fact, this hobby is routed in science. Science takes time, you take small steps to form a hypothesis and for this hobby get knowledge and experience. Otherwise, you might take on, more than you can chew and also be discourage by losing your high power kit, with altimeters, motor casings and high cost of the kit. Patience is necessary for every thing we do and yet more and more people especially young, do not have it. And I know because when I was young and even now at 61 years old, I still do not have patience. And you needs tons of patience to assemble a high power kit vs a model rocket. Signed still not ready for HP
 

Zeus-cat

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I've seen college students doing the NASA projects where they basically jump from nothing or very little LPR to high power. Let's just say the results of that L1 cert attempt are often less than optimal.

Take your time, learn how to do things properly, have fun. MPR and LPR aren't required, but for most people, that is probably the best way to do it.
 

boatgeek

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I've seen college students doing the NASA projects where they basically jump from nothing or very little LPR to high power. Let's just say the results of that L1 cert attempt are often less than optimal.

Take your time, learn how to do things properly, have fun. MPR and LPR aren't required, but for most people, that is probably the best way to do it.
Fair point. My older child's IREC team members basically went from Estes D kits to a 20'x8" carbon fiber rocket with a student-designed full O hybrid motor. There's a reason that IREC has about 1/3 fully nominal flights. That said, I think there's a pretty fine line between G and H so there's less learning curve between those impulse levels. There's a much bigger learning curve to L2, which is one reason why I encourage people not to use the same airframe for L1 and L2 certs.
 

ZEDL1

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I agree with Steve Shannon. Although he did not say this, at all, in my view, adding rules upon rules to what is to be an enjoyable and educational hobby, and it is our hobby, is too political for my taste...far too political. I'm old school, and had initial concerns about the now-old need to restructure our Certification system into 3 levels. I, and a great number like me, did more than a bit fine without them.
 

prfesser

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I think it depends in part on one's experience with A-D rockets. Anyone who has some difficulty with building and flying LP kits should definitely take things in small steps. OTOH if you consider LP kits and most scratchbuilds to be pretty simple and un-challenging, the jump from D to H need not be a big deal.

Best -- Terry
 

DaveW6DPS

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There are skills and knowledge required for high power rocketry that does not always result from flying low power rockets.

Keeping in mind that "mid-power" is a poorly defined, essentially made-up category, you have to consider what rockets you are really talking about. A large model rocket, built with model rocket techniques but flying on an E or F, does not help prepare for high power rocketry. A rocket kit built with techniques more in keeping with high power can.

I don't think it is a hard and fast prerequisite, but jumping into high power without the skills and knowledge required can lead to a very step learning curve. Most of the people who want to jump into the deep end without a clue ("What kit can I use for both Level 1 and 2?") would benefit from additional experience.

Learning by trial and error usually involves a lot of error. You hope no one gets hurt and the newb doesn't get frustrated by failure and quit the hobby.
 
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