Cardboard/Plywood Parts to a 100k

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JimJarvis50 said:
Well, it is a little complicated. I've done a lot of calculations, but the information I really rely on is actual flight data. Basically, I know from experience that I can change the tilt of a rocket away from vertical by about 25°/sec with a 5° canard angle. A turn towards vertical is about 10°/sec. I just adjust those values for the flight and variables in question. A long rocket, such as the three stage, turns slower. From a control perspective, proportional control works pretty well, although we have added a derivative term to reduce oscillation. I should stop ...

Jim
Click to expand...
Did you mean 25 degrees/min? Per second is quite fast.
 
I gave the general idea for LOC-style rockets more thought and I wanted to add a few comments on "rules". The only real rule is the rocket needs to be safe by Tripoli and NAR standards. You can use whatever you want. The spirit of this is accessibility and ease of build. So for example if you want to put some epoxy on the fins to prevent delamination, that is within the spirit of this, as that can be done safely and easily in an apartment. If you find yourself vacuum bagging, oven curing, machining parts etc, you are going too far. Maybe another way to think about it. If a determined 8th grader could replicate the build steps in his or her house without causing duress to the parents, you are in the spirit of this challenge.
 
Side boosters will kill you in drag. Use a linear staging magazine. Google Winchester 73 action and implement a version of that concept using ejectable motors
 
AlexBruccoleri said:
Did you mean 25 degrees/min? Per second is quite fast.
Click to expand...
No, 25°/sec. This is for what I consider to be a relatively large canard deflection (I don't allow them more than 7.5° ever). And this is for a turn away from vertical. A turn toward vertical is less, about 10°/sec. As you get closer to the target value, whether that's vertical or some tilt value, the canard deflection starts to decrease and ends up at zero at the target tilt. So, the time to actually reach the target value is typically on the order of 5 seconds or so (going to vertical). I saw this timing in multiple flights early-on. I was expecting a shorter correction period so it took me a while to figure out what was actually happening.

The the rate reasonably characterized, I can now set up a "flight plan" to move the rocket by either changing the tilt up or down or changing the bearing (at a fixed tilt value, so neither tilting up or down for a bearing change). The video below (my Infinity flight) is an example of this. There are approximately 45 direction changes in that flight, with each change starting from wherever orientation the rocket has at the time the change is commanded. This only works if you know how fast the rocket will move for a given rocket stability, canard size/deflection and velocity.

Jim

 
jderimig said:
Side boosters will kill you in drag. Use a linear staging magazine. Google Winchester 73 action and implement a version of that concept using ejectable motors
Click to expand...
You are probably right on side boosters. I did a sim with a 9 inch rocket, core N1000 and 6x k250s and got to around 60k lighting them in sequence. The same rocket with J510s instead gets to around 40k. A 98 mm and 6 x 38 will fit in the 7.5" tubing though. That might be a sufficient first stage.
 
AlexBruccoleri said:
You are probably right on side boosters. I did a sim with a 9 inch rocket, core N1000 and 6x k250s and got to around 60k lighting them in sequence. The same rocket with J510s instead gets to around 40k. A 98 mm and 6 x 38 will fit in the 7.5" tubing though. That might be a sufficient first stage.
Click to expand...
Just to ask, you say 9 inch, but LOC atm deal with 7.5 max, at least from what I can see on the website.
 
JimJarvis50 said:
No, 25°/sec. This is for what I consider to be a relatively large canard deflection (I don't allow them more than 7.5° ever). And this is for a turn away from vertical. A turn toward vertical is less, about 10°/sec. As you get closer to the target value, whether that's vertical or some tilt value, the canard deflection starts to decrease and ends up at zero at the target tilt. So, the time to actually reach the target value is typically on the order of 5 seconds or so (going to vertical). I saw this timing in multiple flights early-on. I was expecting a shorter correction period so it took me a while to figure out what was actually happening.

The the rate reasonably characterized, I can now set up a "flight plan" to move the rocket by either changing the tilt up or down or changing the bearing (at a fixed tilt value, so neither tilting up or down for a bearing change). The video below (my Infinity flight) is an example of this. There are approximately 45 direction changes in that flight, with each change starting from wherever orientation the rocket has at the time the change is commanded. This only works if you know how fast the rocket will move for a given rocket stability, canard size/deflection and velocity.

Jim

Click to expand...

Thanks for clarifying and that is quite impressive. I think that type of control system would make a low-speed first stage possible for a 100k attempt.
 
AstroAbaqus said:
Just to ask, you say 9 inch, but LOC atm deal with 7.5 max, at least from what I can see on the website.
Click to expand...
I was just hacking around with Rock Sim and upscaled a LOC Ultimate. 7.5" is the max diameter for LOC tubing. It is worth noting though that 7.5" LOC rockets are on the border of accessibility/ease of build though.

I agree with some of sentiment of other posters that it is time to stop talking and start building. I asked Jay at LOC if they plan to make more Laser Loc 313 kits. Just building that is a good way to start this. Then try making a two stage version. Either add a 38 or 29 mm, minimum diameter sustainer or make the 313 the sustainer to a booster. In a previous post I discourage minimum diameter, however with a small sustainer it can probably be done.
 
AlexBruccoleri said:
I was just hacking around with Rock Sim and upscaled a LOC Ultimate. 7.5" is the max diameter for LOC tubing. It is worth noting though that 7.5" LOC rockets are on the border of accessibility/ease of build though.

I agree with some of sentiment of other posters that it is time to stop talking and start building. I asked Jay at LOC if they plan to make more Laser Loc 313 kits. Just building that is a good way to start this. Then try making a two stage version. Either add a 38 or 29 mm, minimum diameter sustainer or make the 313 the sustainer to a booster. In a previous post I discourage minimum diameter, however with a small sustainer it can probably be done.
Click to expand...

I think that in anyway you want to try this you have to go by steps. Already doing a modification of Laser Loc would be a nice one. I think is good to talk, this helps to pull out ideas. I am sure that the next step will be to start to design it, maybe CAD and/or OR.
 
AlexBruccoleri said:
I was just hacking around with Rock Sim and upscaled a LOC Ultimate. 7.5" is the max diameter for LOC tubing. It is worth noting though that 7.5" LOC rockets are on the border of accessibility/ease of build though.

I agree with some of sentiment of other posters that it is time to stop talking and start building. I asked Jay at LOC if they plan to make more Laser Loc 313 kits. Just building that is a good way to start this. Then try making a two stage version. Either add a 38 or 29 mm, minimum diameter sustainer or make the 313 the sustainer to a booster. In a previous post I discourage minimum diameter, however with a small sustainer it can probably be done.
Click to expand...
If you want to get started, just begin with a LaserLOC 163 since it's already a reasonably good sustainer and quite inexpensive. When you have some good headend deploy success with the AT I59, work up a 3 or 4in booster as a standalone rocket. THEN worry about staging them, and after that maybe upscaling to the expensive end.
 
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dhbarr said:
If you want to get started, just begin with a LaserLOC 163 since it's already a reasonably good sustainer and quite inexpensive. When you have some good headend deploy success on it, work up a 3 or 4in booster as a standalone rocket. THEN worry about staging them, and after that maybe upscaling to the expensive end.
Click to expand...
The LaserLOC 163 looks like a great rocket too. Thanks for sharing.
 
I should make a correction. Rock Sim saved my fictitious starting altitude in new rocket sims so the numbers I posted before were bogus. (I am not sure why it does this for sims.) Anyway I am getting closer to 70k for a N1000-L400-K250 in 5.5" to 3" rocket and my air-started 9 inch booster N1000-6x K250 lit in pairs of two is closer to 20k. These numbers are more in line with my intuition but I still think this is possible, though no doubt very hard.

Below are three scenarios I can think to pull this off:

1. 3 stage rocket and be clever in construction so the rocket can hit Mach 1.5 while still in thickish air. An M750 for example as my second stage will work.

2. 4 stage rocket and keep the first two stages slow.

3. 3 stage rocket with air-started strap ons or a wide booster.

In terms of action, I think it is worth exploring how fast LOC rockets can go. That will be fun, inexpensive and yield good data for how far the envelope can really be pushed. Scenarios 2 and 3 work in theory, but they would be a lot of work and money to pull off.
 
AlexBruccoleri said:
I should make a correction. Rock Sim saved my fictitious starting altitude in new rocket sims so the numbers I posted before were bogus. (I am not sure why it does this for sims.) Anyway I am getting closer to 70k for a N1000-L400-K250 in 5.5" to 3" rocket and my air-started 9 inch booster N1000-6x K250 lit in pairs of two is closer to 20k. These numbers are more in line with my intuition but I still think this is possible, though no doubt very hard.

Below are three scenarios I can think to pull this off:

1. 3 stage rocket and be clever in construction so the rocket can hit Mach 1.5 while still in thickish air. An M750 for example as my second stage will work.

2. 4 stage rocket and keep the first two stages slow.

3. 3 stage rocket with air-started strap ons or a wide booster.

In terms of action, I think it is worth exploring how fast LOC rockets can go. That will be fun, inexpensive and yield good data for how far the envelope can really be pushed. Scenarios 2 and 3 work in theory, but they would be a lot of work and money to pull off.
Click to expand...

I would also suggest thinking about guidance, after reviewing work done by other flyers I can see that flying a lot and learning the art of guidance and control is crucial to do not lose height and flight straight. If I have to approach this challenge, or anyway a high flight such as this one. I would try to master control with some long burn. This is something I will do, whatever it takes but I still learning:).
 
AstroAbaqus said:
Absolutely a nice entry kit for high speed and minimum diameter.
Click to expand...
AlexBruccoleri said:
In terms of action, I think it is worth exploring how fast LOC rockets can go. That will be fun, inexpensive and yield good data for how far the envelope can really be pushed.
Click to expand...

Yes, it's a fun rocket, at a good price, and it is capable of going fast (at least Mach 1.3) and high as well.

https://www.rocketryforum.com/threa...-on-level-1-motors-with-modifications.159420/
 
AlexBruccoleri said:
In terms of action, I think it is worth exploring how fast LOC rockets can go. That will be fun, inexpensive and yield good data for how far the envelope can really be pushed. Scenarios 2 and 3 work in theory, but they would be a lot of work and money to pull off.
Click to expand...
"Speed of paper" probably better stated as "max Q of paper"
 
AlexBruccoleri said:
It is a 3-fin rocket.
Click to expand...

I got one in OpenRocket to hit 58k only. That's using same motor combo you listed above, but a 4" MD first stage, a 4" second stage, and a 3" third stage all 3 and 4 clipped delta fin design - trying to keep as small of fins vs weight and achieve around a 1.25-1.55 stability. Each one has dual GPS receivers as well as dual altimeters for recovery. 215" in length - mostly for motors and accommodating room for shock chord and parachute based on FC's packaging dimensions.

Its long and foldy. :| There may be some areas that could be tightened up a bit, like use of more compact horizontally stacked instead of verticallly stacked altimeters (I just grabbed my current working avbay and reused)

I was mostly just curious - I'm only working on L2 now, so any look at doing something like this (probably not that interested really unless huge group project) is quite a long journey off.

Capture.PNG
 

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thzero said:
I got one in OpenRocket to hit 58k only. That's using same motor combo you listed above, but a 4" MD first stage, a 4" second stage, and a 3" third stage all 3 and 4 clipped delta fin design - trying to keep as small of fins vs weight and achieve around a 1.25-1.55 stability. Each one has dual GPS receivers as well as dual altimeters for recovery. 215" in length - mostly for motors and accommodating room for shock chord and parachute based on FC's packaging dimensions.

Its long and foldy. :| There may be some areas that could be tightened up a bit, like use of more compact horizontally stacked instead of verticallly stacked altimeters (I just grabbed my current working avbay and reused)

I was mostly just curious - I'm only working on L2 now, so any look at doing something like this (probably not that interested really unless huge group project) is quite a long journey off.

View attachment 500878
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I do not have OR yet, so I cannot mess with the sim. What is your second stage? Also try making all the stages shorter.
 
rfjustin said:
So when do parts get ordered for this project?
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As stated several times before, I am not looking to do this challenge. I have no access to black rock and barely any access to a waiver > 4500 ft. I did order a custom LOC Magnum for 98 mm motors though and I plan to post on that build. If I get to MDRA or Potter I can try pushing that rocket.
 

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