Gimbal

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Area66

Well-Known Member
Joined
Apr 5, 2013
Messages
2,251
Reaction score
4
Ok I will work on a project involving active stabilisation with Gimbal. as I said in another post one of the problems of Canards and Guardian is the lack of processing power to anticipate the amount of correction needed to not over correct and create more problems. With Gimbal it will be the same problem except I think if we use a cluster of fix motors to surround the gimbal one. It will create some sort of inertia. The goal is to get a slow liftoff similar to real rocket send to space.

cluster_zpsmklxtghx.jpg


This is a long effort project, my weakness is the programing. But I have first to establish the goal and after it will be more easy to achieve it. First think, I was thinking to use a spherical bearing made of polymer, to hold the motor tube at his base and some sort of cam system to pivot the motor tube on the top.

I find some source in Europe nit it’s seem to not be popular here on in US

igubal_egfm_1_zpswrkzn14h.jpg



I think the best approach will be to make a rocket on a skeleton and use some king of skin over it , this will be more easy to work on a skeleton than force my hands in tube.
 
Last edited:
Best of luck!!!

I will need more than luck, it's a real long time project with a lot of effort and trial and errors. But I'm not the typical first post guy who come with crazy idea, this thing can and will work. I study what other have tried and the problem is their system do too much correction, it make the rocket even less stable. So I want at first give less correction, use more inertia, even if it’s results in a less than vertical fly, most important it’s to be strait at first or at least in a nice curve with a trust/weight ratio close to 2:1 and lower when I will gain experience.
 
Last edited:
I don't doubt it, and my remark was sincere, not flippant or sarcastic.
I too would love to see more technology integrated into the stabilization of model rockets.
I have yet to even fly an altimeter. 808 Cams are about as tech as I've got so far.
 
I know Top, I know...

One of the advantages of my fix motors cluster around the gimbal one will be that it’s a progressive approach. I can use like 3 H motor for the cluster and 1 G for the gimbal, this will have less impact on the fly, correction can be progressive too, a little step at the time, with each launch, flight data will be recorded and results analysed.

What I need to go is to start the motion, we don’t know may be a team will form and thing will go faster.
 
I happen to disagree with Jim Jarvis on this one. Alyssa Stenberg showed the Guardian works just fine in her NARAM presentation. She used it for gimbaled motors and for canards. And she made the videos to prove it.

[YOUTUBE]A4M9Uso9EsY[/YOUTUBE]

Bob
 
From another discussion the OP seems to want to provide that same majestic (for lack of a better word) seemingly low speed launch that was the hallmark of the Saturn 5 and the like. My only thing is the fact that most of our motors don't burn anywhere near long enough for that type of guidance.
 
From another discussion the OP seems to want to provide that same majestic (for lack of a better word) seemingly low speed launch that was the hallmark of the Saturn 5 and the like. My only thing is the fact that most of our motors don't burn anywhere near long enough for that type of guidance.


a K185W burn 7 secondes , I will be happy with 800 feet will be ok with 500 of altitude
 

In 1999, 15 years ago, can you believe no one have done anything since that time , I hope peoples understand my idea, I don’t want to rely only on the gimbal for the first flights. Clusters, fins and speed will help to experiment. I want to have a 100% functional system before give it a 100% trial ( software, cam system, ….everything 100% running ) I don't want a cowboy aproach or what peoples like to use here, basement bomber aproach
 
Last edited:
I happen to disagree with Jim Jarvis on this one. Alyssa Stenberg showed the Guardian works just fine in her NARAM presentation. She used it for gimbaled motors and for canards. And she made the videos to prove it.


Bob

What do we disagree about? It's obvious that Alyssa was able to use the Guardian for the flight profiles she tested. And, the OP's objectives might be within its capabilities too. I do see significant limitations taking that device much further, though.

Jim
 
I happen to disagree with Jim Jarvis on this one. Alyssa Stenberg showed the Guardian works just fine in her NARAM presentation. She used it for gimbaled motors and for canards. And she made the videos to prove it.

[YOUTUBE]A4M9Uso9EsY[/YOUTUBE]

Bob


And that girl is'nt even a member of Rocketry Forum as far as I know. What's up with that???
 
I have a life outside rocket, I make also model train, fish keeping and stamp collecting........... :facepalm:
 
What do we disagree about? It's obvious that Alyssa was able to use the Guardian for the flight profiles she tested. And, the OP's objectives might be within its capabilities too. I do see significant limitations taking that device much further, though.

Jim

Hi if I read the post of Bob in your I think I know where he disagrees. ( it’s about the timing when you activate the system ) I think my project and yours have the same limitations; ; The guardian is too limited, it make over correction that make the rocket even less stable. The best you gone get is sine wave like in the video of the college girl. But it’s already not that bad if the rocket stay vertically over the pad. This is why I want first use a cluster around the gimbal and limit the side play of it. I want to be able to keep control on the rocket as I do my experimentation and calibration. I think you can achieve it also if you use very little canards. Just to see how the system react and collect data. But we have both the same problem; we need a real flight computer. 1 step at the time I will build my test rocket, use a guardian but limit the side play and try to keep an inertia with the 3 motors in cluster around the gimbal.
 
Last edited:
Hi if I read the post of Bob in your I think I know where he disagrees. ( it’s about the timing when you activate the system ) I think my project and yours have the same limitations; ; The guardian is too limited, it make over correction that make the rocket even less stable. The best you gone get is sine wave like in the video of the college girl. But it’s already not that bad if the rocket stay vertically over the pad. This is why I want first use a cluster around the gimbal and limit the side play of it. I want to be able to keep control on the rocket as I do my experimentation and calibration. I think you can achieve it also if you use very little canards. Just to see how the system react and collect data. But we have both the same problem; we need a real flight computer. 1 step at the time I will build my test rocket, use a guardian but limit the side play and try to keep an inertia with the 3 motors in cluster around the gimbal.

I think Bob just wants us to not overlook that the Guardian has been used successfully for stabilization (although he can speak up if that's not the case).

With respect to the Guardian, I wouldn't call it "too limited" in its ability to control a flight path. The proportional control it uses at a minimum will do that just fine and will not necessarily result in a sine wave. I'm using proportional control and I don't think anything else is needed, at least for my use. My issue with the Guardian is the lack of information about what it actually does in all circumstances. EagleTree doesn't want us using it for rockets - it's not designed for them. They have, however, confirmed that they do not deactivate the accelerometers at any point during normal use. Based on my limited experience and understanding of how these devices work, I believe that this factor alone disqualifies it for use in HP rocketry. But not to worry. Within a relatively short time, rocketeers will have access to a stabilization system that has been tested for rockets, that can be used off the shelf or programmed, at a cost of about $80.

Jim
 
I'm not sure what I'm reading here.

The way I interpreted the original post is that Area66 is looking to solve problems that haven't been addressed for the past 15 years, at least. He is suggesting that technologies applied to other areas of modelling have somehow passed this rocketry community by. In particular, having to walk to an unpredictable place to recover a rocket. If my interpretation is correct (and I stand to be corrected by Area66) then I agree with his question.

Surely the answers cry out for innovation from the those experienced in model rocketry and not reference to ballistic missiles and ITAR!
Design to need, cost and environment.

I recognise that cost is a big issue, compliance to safety and law equally so. But where is the innovation from the "cream" of the world's model rocketeers on this site?
If it has not been forthcoming for the past 15 years then Area66 has a point worth addressing and most importantly, answering simply.

Regards.
SO.
 
Ok I will not give detail of my work, but I want to address the electronic part of the project. I want to use what I will call Rocket-Network, this will allow me to have interoperability between every module in the rocket including also the telemetry and the ground station computer, I will not re-invent the wheel, we have in Model railroading something that work fine and can be simply modify for rocketry. So each module will have a power supply, a microprocessor, some will have input and control other only input or control. I will also use a special software layer to the already existing network topology to adapt it to rocketry. I’m very lucky o have help for the company who produce the Model Railroad modules; they Will adapt for me some prototype modules. I will not go in detail as the company may be interested to put in the market this product once developed.
 
Back
Top