What do you think is the future of model rocketry electronics/technologies?

[Spacedog49Krell]

Nice, Krell !

I've seen your data -- it looks great !

Will this be a commercial product ?

Do you have any pics of the gadget ?


My dad was a ChemE who also loved math.

He had us playing with chemistry sets when we were in elementary school.

He might have taught us about oxidizers long before we should have learned about the fun stuff

-- kjh

The 1000Hz & 1600Hz(prototype) are for my experimental use. I'm not giving Adrian or Cris any competition, I'm too old for that. I may nudge Adrian towards higher speeds. Each time I doubled my sampling speed it opened the vista of potential rocket studies by 4X. Now, at 1000Hz I'm hoping to see issues that have not been considered.

The picture is of the 500Hz 18mm proto. The 1000Hz proto is 10mm longer.

In HS chemistry class I was doing nuclear isotope separations. I also graduated from nitrate to perchlorate propellants in HS. I went to HTPB in 1973. The same year Gary fired his first successful polyester E motor.


Update: The latest 18mm prototype 4 now looks identical to prototype 1 (pic). I found that I had one Adafruit QTPY RP2040 in an old project box. The latest software changes record microseconds, 3- 30G accel, and 3- 4000°/sec gyros at 1000Hz with 3 channels of barometric data at 50Hz. All, including battery, <28 grams for the prototype. I was hoping to go to a launch, but we are under a Fire Ban. Maybe real data in October.

 

[lr64]

But why do we need that much energy to deploy recovery? Seems like a weakness of the recovery deployment concept doesn't it?

I don't remember specifying just how much energy. I'm not at all sure that, when I saw lead azide go off, there was enough to deploy a parachute from all but the smallest rockets. It's a chemical, not a size or a particular deployment system. Ditto nitroglycerine, except I haven't seen any go off by itself. It's possible I've seen guns or ejection charges with double base powder fired, I suppose. As far as the unknown, transuranic elements, in the future, there's no telling how much energy is required. ;-)

Anyway, if the weight is kept down, and it works right, what's wrong with a little energy? Certainly it's FAR less than it takes to drive to the field or even the energy that goes into the hamburger you have for lunch at the launch.

 

[jderimig]

The 1000Hz & 1600Hz(prototype) are for my experimental use. I'm not giving Adrian or Cris any competition, I'm too old for that. I may nudge Adrian towards higher speeds. Each time I doubled my sampling speed it opened the vista of potential rocket studies by 4X. Now, at 1000Hz I'm hoping to see issues that have not been considered.

The picture is of the 500Hz 18mm proto. The 1000Hz proto is 10mm longer.

In HS chemistry class I was doing nuclear isotope separations. I also graduated from nitrate to perchlorate propellants in HS. I went to HTPB in 1973. The same year Gary fired his first successful polyester E motor.

What is your SD card SDIO bandwidth?

 

[Spacedog49Krell]

What is your SD card SDIO bandwidth?

QSDIO at 2.0Mbps

 

[MidOH]

-A simple 4 fin and tube kit with couplers that can be added to any kit, to give active stability control to the center of a payload section on a 3 or 4" rocket. With a hollow center pass through for ejection charge gasses.

-Drone catch. Like sky hook. FFS, our shock cords are 50' long on some high powered models. Put a mirror on the shock cord, program a drone to grab it.

A kinetic anti-drone, could already pull this off with nothing more than a V added to it's tail.

Might take too much fun out of rocketry though.

-deployable grid fins for a ballistic first stage of recovery. To coordinates of a landing area. Feathering the fins for extra drag as altitude decreases.

-land boosters with legs and thrust like SpaceX does.

-cameras that don't suck. Probe cameras.

 

[Spacedog49Krell]

The 1000Hz & 1600Hz(prototype) are for my experimental use. I'm not giving Adrian or Cris any competition, I'm too old for that. I may nudge Adrian towards higher speeds. Each time I doubled my sampling speed it opened the vista of potential rocket studies by 4X. Now, at 1000Hz I'm hoping to see issues that have not been considered.

The picture is of the 500Hz 18mm proto. The 1000Hz proto is 10mm longer.

In HS chemistry class I was doing nuclear isotope separations. I also graduated from nitrate to perchlorate propellants in HS. I went to HTPB in 1973. The same year Gary fired his first successful polyester E motor.


Update: The latest 18mm prototype 4 now looks identical to prototype 1 (pic). I found that I had one Adafruit QTPY RP2040 in an old project box. The latest software changes record microseconds, 3- 30G accel, and 3- 4000°/sec gyros at 1000Hz with 3 channels of barometric data at 50Hz. All, including battery, <28 grams for the prototype. I was hoping to go to a launch, but we are under a Fire Ban. Maybe real data in October.

Update on the 18mm & 24mm 1000Hz Flight computers:

Attached is 4-5 rps twirl test data graphs. My flight computer equivalent to the string stability test.

 

[2-0turbo]

48 MPa with ABS on a hobby device, any metal you want on a SLA print from a company like PCB way.

You are mixing units. 48 MPa is about 7,000 psi or 7 KSI. The ABS you mention is 7% the strength of the hypothetical 100 KSI steel. I’m not aware of any FDM plastic that can approach steel physicals—epoxy/CF composites are the only thing I’m aware of and they require either specialized equipment (filament winder) or a lot of labor.

The additive manufacture is an interesting angle though. The metal 3D printers are getting more capable by the day and the part cost is coming down rapidly. Still not affordable for us, but it will likely get there in the next ten years.

 

[NTP2]

You are mixing units. 48 MPa is about 7,000 psi or 7 KSI. The ABS you mention is 7% the strength of the hypothetical 100 KSI steel. I’m not aware of any FDM plastic that can approach steel physicals—epoxy/CF composites are the only thing I’m aware of and they require either specialized equipment (filament winder) or a lot of labor.

The additive manufacture is an interesting angle though. The metal 3D printers are getting more capable by the day and the part cost is coming down rapidly. Still not affordable for us, but it will likely get there in the next ten years.

This stuff is expensive but it’s as strong as metal (like steel metal not gold) from the demo videos I’ve seen. Metal printed parts are pretty affordable form these companies from what I’ve seen, and in say case if you need it you will be spending a lot more on a one use item!!

 

[dhurstell]

I think kits that gimbal the motor will be commercially available. You can choose to make a rocket that flies finless, or choose to make a rocket that flies perfectly straight despite weather conditions. GPS tracking will become more standardized, and a general purpose flight computer that gives decent telemetry will become as easy as sticking a Pi-Zero with a radio module that sends everything to your laptop.

Of course, someone needs to develop this stuff. All the technology already exists, we just need someone to piece it all together as a kit for us dum-dums.

You CAN make those things.

But if you can just buy them off the shelf, then you dont UNDERSTAND what you're doing, and someone could get hurt.

It sounds like elitist gatekeeping, IMO but the knowledge and skill required to fly with ANY type of guidance must be earned and demonstrated along the way.

 

[Azamiryou]

It sounds like elitist gatekeeping, IMO but the knowledge and skill required to fly with ANY type of guidance must be earned and demonstrated along the way.

That does sound like elitist gatekeeping. How does it not also apply to all the stuff already available in kits and ready-made?

 

[Capt. Eric]

You CAN make those things.

But if you can just buy them off the shelf, then you dont UNDERSTAND what you're doing, and someone could get hurt.

It sounds like elitist gatekeeping, IMO but the knowledge and skill required to fly with ANY type of guidance must be earned and demonstrated along the way.

Why should someone have to make these things and not get them off the shelf? Plenty of us fly with engines that are off the shelf. Some even fly RTF rockets that they didn't build. Most (not all) of these fliers are probably safe. I didn't build my own JL Chute Release. I hope I don't hurt someone with it because I'm not good at small soldering and programming. Should we all have to build our own automobiles so that we don't hurt someone when we drive them? I would think the UAW might take issue if that one gets into law.

 

[Spacedog49Krell]

Build, learn, understand, and influence the entrepreneurially gifted to make available products that turn today's science fiction into tomorrow's reality.

 

[dhurstell]

Why should someone have to make these things and not get them off the shelf? Plenty of us fly with engines that are off the shelf. Some even fly RTF rockets that they didn't build. Most (not all) of these fliers are probably safe. I didn't build my own JL Chute Release. I hope I don't hurt someone with it because I'm not good at small soldering and programming. Should we all have to build our own automobiles so that we don't hurt someone when we drive them? I would think the UAW might take issue if that one gets into law.

The level of knowledge you have to understand how to use, let alone WHY to use a JL chute release exceeds the RTF kit buyers by 1000%. You know what all the letters and number mean, and how a B4-4 may struggle to lift what an A8-5 might be ok with.

People take drivers' education AND take a drivers test AND have to maintain a license AND INSURANCE to drive a vehicle.

 

[Spacedog49Krell]

The level of knowledge you have to understand how to use, let alone WHY to use a JL chute release exceeds the RTF kit buyers by 1000%. You know what all the letters and number mean, and how a B4-4 may struggle to lift what an A8-5 might be ok with.

People take drivers' education AND take a drivers test AND have to maintain a license AND INSURANCE to drive a vehicle.

Your motor designation is not a good example. The first letter designates the Total Impulse of the motor. The first number should designate the average thrust for the motor. For the B4, the average thrust is in the 4.2 - 4.9 Newton range. For the A8, the average thrust is 3.2 - 4.2 Newtons and it should carry the average thrust designation of 3 or 4, but it was grandfathered in as an 8, since the motor designation of A8 existed prior to the NAR coding system.

 

[dhurstell]

Your motor designation is not a good example. The first letter designates the Total Impulse of the motor. The first number should designate the average thrust for the motor. For the B4, the average thrust is in the 4.2 - 4.9 Newton range. For the A8, the average thrust is 3.2 - 4.2 Newtons and it should carry the average thrust designation of 3 or 4, but it was grandfathered in as an 8, since the motor designation of A8 existed prior to the NAR coding system.

See that, by arguing the point.. you've demonstrated your knowledge and made the point =)

 

[Azamiryou]

The level of knowledge you have to understand how to use, let alone WHY to use a JL chute release exceeds the RTF kit buyers by 1000%. You know what all the letters and number mean, and how a B4-4 may struggle to lift what an A8-5 might be ok with.

People take drivers' education AND take a drivers test AND have to maintain a license AND INSURANCE to drive a vehicle.

So if a manufacturer decided to offer a RTF rocket that came with a JLCR (and instructions for how to use it with the rocket), that would be a bad thing? I don't think so, but okay

 

[Spacedog49Krell]

Update on the 18mm & 24mm 1000Hz Flight computers:

Attached is 4-5 rps twirl test data graphs. My flight computer equivalent to the string stability test.

The 24mm 1000Hz flight computer is ready for flight tests this weekend. Weight is 31 grams with 400mAh LiPo. The 18mm is progressing and it also might fly this weekend, pending I finish the BT-20 rocket.

 

[PaddyDaddy]

Vashon rockets

What's a Vashon rocket, please?

 

[lr64]

You CAN make those things.

But if you can just buy them off the shelf, then you dont UNDERSTAND what you're doing, and someone could get hurt.

It sounds like elitist gatekeeping, IMO but the knowledge and skill required to fly with ANY type of guidance must be earned and demonstrated along the way.

I wonder what Joe Barnard's experience with his customers has been with his TVC system?
https://bps.space/products/signal-r2
I also wonder how hard it would be to adapt something like that to control fins instead? No doubt he knows the answer to that one. And I wonder what happens to TVC rockets that have no fins when the motor cuts out.

 

[Sooner Boomer]

What's a Vashon rocket, please?

Estes freon-powered rocket from the '70s

 

[cwbullet]

Smaller, lighter, cheaper.

I would like to think so. I really liked Flight Sketch. They just disappeared.

 

[SolarYellow]

AFAIK, that wasn’t due to lack of demand. It was personal issues of the owner to the point that he had finished assemblies on hand and never got them programmed and ready to ship. Eventually, placing an order for items that the website indicated were in stock just got the payment refunded without any other communication, rather than shipping it out.

The Featherweight Blue Jay suggests I might have been on track.

 

[Handeman]

And I wonder what happens to TVC rockets that have no fins when the motor cuts out.

pretty much what you expect, no control at all. I think that is why TVC has never been a big thing in hobby rocketry. Our motors tend to be short burn time. The fin control would seem to be more desirable for hobby rockets that stay in the atmosphere where TVC is better for long burn extra-atmospheric flights which are way beyond hobby flights.

 

[lr64]

pretty much what you expect, no control at all. I think that is why TVC has never been a big thing in hobby rocketry. Our motors tend to be short burn time. The fin control would seem to be more desirable for hobby rockets that stay in the atmosphere where TVC is better for long burn extra-atmospheric flights which are way beyond hobby flights.

I wonder how much air is required for fin control. Some of those hobby flights get pretty high. I found one in the Tripoli records that was over 150,000 feet, and several above 100,000.

 

[boatgeek]

I wonder how much air is required for fin control. Some of those hobby flights get pretty high. I found one in the Tripoli records that was over 150,000 feet, and several above 100,000.

Pretty much any of the very high altitude flights (say over 200K) that have gyro data show some loss of fin authority in the form of tumbling. You could look at where that tends to start.

 

[Capt. Eric]

Pretty much any of the very high altitude flights (say over 200K) that have gyro data show some loss of fin authority in the form of tumbling. You could look at where that tends to start.

I don't think my Marco Polo would be able to track that flight!

 

[Spacedog49Krell]

Above 90K ft you have loss of aerodynamic control through fins. The simplest cold jet stability system uses one nozzle and one rate gyro on a spinning rocket. I believe I still have all the equations from 1966.

 

[Handeman]

I wonder how much air is required for fin control. Some of those hobby flights get pretty high. I found one in the Tripoli records that was over 150,000 feet, and several above 100,000.

Looking at those flights is kind of like looking only at speeding tickets issues for over 200 mph. Very few and far between. The people that fly that high are at the very top of the "hobby" level, just like someone that builds and drives a +200 mph car.
I've never heard of a flight that high that did any type of TVC or fin control for that matter. I could be wrong, but I haven't heard of a hobby flight like that.

 

[lr64]

pretty much what you expect, no control at all. I think that is why TVC has never been a big thing in hobby rocketry. Our motors tend to be short burn time. The fin control would seem to be more desirable for hobby rockets that stay in the atmosphere where TVC is better for long burn extra-atmospheric flights which are way beyond hobby flights.

If someone had their level 2 with Tripoli, they could make special long burn motors that tapered off. Might be interesting and, with lightweight design, might get to some pretty high altitudes.

 

[Spacedog49Krell]

If someone had their level 2 with Tripoli, they could make special long burn motors that tapered off. Might be interesting and, with lightweight design, might get to some pretty high altitudes.

Long burn motors, past 20+ seconds, requires special propellant insulation knowledge. Knowledge that is not well understood. I know that Joe Barnard is working on such insulation. On the Aerotech web site there is a paper published by Bill Wood on "Moonburners" which can produce very long burns. In the paper there is information on a ~6" Moonburner that has burned 36 seconds and 54 seconds. A long duration motor of that type could utilize TVC technology.