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High Power Rocket Boat (X6)

I’ve been taking my 3d printed rocket boat to the next level through scaling it up and adding more engines!

With the success of my micro hydroplanes, the natural succession was to do more testing. Here’s my video.

Build

Firstly I scaled up the boat on CAD and got to work printing out all the parts I needed. This boat is twice the size of the previous boats I was playing around with last month which should help with stability when going over small ripples and waves at high speeds. This didn’t take too long as I’ve now got three printers to speed up big print projects. I assembled the pieces and painted them with paint and then spray sealant which would make it waterproof

Propultion

I wanted to start small-ish and work upwards, combining motors with higher and higher powers until either the boat destroys itself or we find another limiting factor. These engines are all black powder engines that work through burning a propellent which flings loads of hot gas out the back at extremely quick speeds. The resulting reaction forces the boat in the other direction. To make the motors easy to swap out and combine into clusters of engines, I made this modular design of engine adaptor where you can slide them in and out of the back of the boat.

I wasn’t really sure if it was such a great idea to combine so many motors as I’ve found in the past lighting them all simultaneously is not always too reliable. To try to get a reliable connection I soldered all the igniters up to one feed and then ran an experiment

Based on the poor result of that test, I decided to use fewer but higher power motors to get a similar amount of thrust from five of these small motors, which was a shame because they looked pretty cool.

Test Run 1 – with 1x Estes D motor

So what benchmark speed could we get with the first rocket motor? The track was a couple of lengths of guttering filled with water. To accurately measure the velocity of the boat, I stuck up these reference squares and pointed a high speed camera at them. I could then calculate the speed by watching it back and seeing how long it took for the boat to clear them. At the end I piled some snow to catch the boat, which was a terrible idea!

On that first run the boat got up to an eye watering 10.638m/s or 23.796mph so it was time for more rocket engines. Firstly though, when watching the video back in my workshop, I’d noticed the boat was jumping along quite a lot. This was probably caused by a negative angle of attack of the boat so I adjusted the sponson angle to raise the nose up a bit. It would be interesting to see what effect this had.

Test Run – with 2x Estes D motors

Now to double the power with two D size engines. At first I failed to ignite both motors at the same time!

Test 3 – attempt 2 at 2x Estes motors.

This run showed I had improved the speed of the boat but at the cost of stability. I found the nose up angle of attack resulted in the craft trying to take off as air got under the nose. It basically started to do a Donald Campbell

Test 4 – attempt 3 at 2x Estes motors

I adjusted the sponsons again, just a little, to reduce the angle of attack of these contact points. Rerunning the 2x D motor test didn’t go to plan though, as, yet again, the dual rocket motor setup failed to light. I managed to fix the damage.

Test 5 – with 1x Cesaroni Pro29 F motor

Undeterred, I really wanted to know what would happen by doubling the thrust again with an F motor with 14.5kg of peak thrust. I adjusted the sponson angle yet again in an effort to point the nose down – go too far though and I’d get the bouncing I experienced in the first test, and perhaps high speed submarine-ing, which is what happened with my smaller rocket boats in my previous video. As expected, it didn’t end well.

I’d learned lots of useful things about behavioural changes with sponson angles, and this will be important for future hydroplane builds and, specifically, with making sure they don’t fly! It seems the hydroplane goldilocks zone only gets narrower and more perilous as speed increases, so perhaps there is a limit to how fast a boat will go. We’ve reached a barrier with this boat, but I it’s a barrier I intend to break going forward.

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Magnus Effect Plane

RC Magnus Effect Plane

This was one of those projects that took a huge amount of work and trial an error to work – but when it actually flew, it was worth all of it.

The Magnus effect is a very strange phenomenon. It’s the force exerted on a rapidly spinning cylinder or sphere moving through air in a direction at an angle to the axis of spin. This force, if angled correctly, can be a lifting or propelling force. In this case, I used the magnus effect as a lift force to replace the wings of an airplane.

But why was my aircraft shaped the way it was? I got a ton of comments saying I should have configured it like a ‘standard’ airplane with a fuselage trailing back to a horizontal and vertical stabilizer. However, my research before getting stuck into building stuff for this project suggested that this addition was probably unnecessary, and I’d be more likely to succeed in seeing a lifting force in action on a para motor type aircraft. I am yet to play around with any other configurations, but I think my final version showed that a very unconventional layout worked very well!

If there’s enough interest I’ll release some files for this, but they were extremely rough and ready when working on this project and I haven’t bothered smoothing them out.

Here’s the video if you haven’t seen it yet.

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Micro Rocket Boats

Rocket Boat Hydroplane Main Product Image

I hope you enjoyed my latest video on the small rocket hydroplanes I’ve been messing around with over the last month. They’re a lot of fun and I think you should make some too (although just as desk models! Do not try what I was doing at home!). Here is a link to a folder where you can download the STL files and instructions to build your own:

LINK TO DOWNLOAD!

Let me know if you have any problems downloading the files.

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Bluebird Hydroplane So Far

My all-time hero is Donald Campbell. You probably already know that if you’ve seen enough of my videos; I’ve made a few hydroplanes and some of them are very blue.

Hydroplanes fascinate me. They’re a weird cross of a boat with an aircraft in that these boats use lift to raise themselves all the way to the top of the water, where they can accelerate with a relatively tiny amount of hydrodynamic drag.

Donald Campbell was famous for breaking water speed records in a big blue jet powered hydroplane named Bluebird K7. This boat was (and still is) a beast, and reached some unbelievable speeds throughout it’s 12 year record-breaking career with Donald in the pilot’s seat.

Seeing as though it was originally Bluebird K7 that got me interested in hydroplanes, and wanting to build some of my own to investigate this unique vehicle type, I’ve ended up building a big blue boat of my own. This is my current hydroplane, and right now I’m in the process of rebuilding it into a jet-propelled model with my Swiwin SW120B turbojet engine.

Originally, it was propelled with two large brushless outrunner motors as an airboat. It was always intended as a sort of large test bed to learn about hydroplaning.

If you haven’t already, watch the initial build video of this boat right here!

Here’s the video of me testing Bluebird with the electric motor setup.

I felt the crash was a good opportunity to take what I’d learned from the test running and rebuild the boat.

Initially, I had wanted to build a land based vehicle as my first project to use my shiny new (and quite expensive) turbojet. Keeping it on the ground, I thought, would probably mean that it would come back in one piece. Thing is, as demonstrated by my rocket car video from last summer, it seems I have a lot to learn about building a car from scratch! Hydroplanes can be less complicated and, as long as the thing doesn’t sink or crash too hard, the engine should still work by the end of the video(s).

In terms of the configuration. The engine will be mounted atop the large hull/fuselage – piggyback style. A large fuel tank will be installed within the fuse at the centre of gravity. Electronics will be further forward, towards the nose. The old carbon motor pylon will be removed.

Lots more will be done to turn this ‘Bluebird’ into an impressive craft worthy of that name! All of that will be the subject of the first video I intend to make taking you through the mods, testing the systems and putting it on a small body of water for some initial slow speed running with jet power!

I can’t wait to get the engine fired up on top of the boat for the first time. I think it’s going to be an amazing project, and definitely the big one for 2022. In the meantime, I’m doing a small project on some small 3D printed rocket hydroplanes you’ll be able to print at home with a file kit.

Check out my YouTube channel for that video!

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Rocket Helicopter (X5)

rocket helicopter

My Rocket Helicopter Development

Here’s the latest single bladed helicopter design I’ve come up with – aaaand of course, it’s now powered by rockets!

I’m thinking about making a file kit for this but I’m not sure if there’s much interest. Let me know if you want to build one.

I’ll be adding more info to this post when I’ve made a file kit for building your own 3D printed rocket helicopter.

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RC Submarine (X4)

Project Air RC Submarine

For as long as I’ve been building boats and other water based projects, I’ve wanted to build a submarine – now I have!

A small, agile submersible would be a useful thing for me to have on standby should something end up at the bottom of a lake. For this reason, I wanted to build a reliable and simple craft that would have the sole purpose of being a scout to search and locate things a few metres down, so I could film and retrieve them. I didn’t quite manage that, which makes this build still a work in progress, but this was a fascinating project to undertake, and I’m still working on it.

Links to helpful info that might help you build a Submarine!

Waterproofing RC electronics guide by Peter Sripol – https://www.youtube.com/watch?v=s4z8Q… Waterproofing a

servo with olive oil – https://www.youtube.com/watch?v=iSKlw…

CorrosionX waterproofing spray- https://www.corrosion-x.co.uk/product…

I plan to post more info about this project when I do some more work on it.

If you haven’t seen it yet, here’s the full video on this project.

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Extreme Aerodynamics RC Car (X3)

I modified an RC car to use some interesting aero devices. Here’s how that went.

I’m interested in the engineering of Formula 1 and how cars went from looking like ‘this’ to ‘this’, with the advent of aerodynamics being used in motorsport to stick cars into the track. I was inspired by watching Driver 61’s video on Pikes Peaks cars which have zero rules which result in crazy designs with huge aero devices to take on the fierce course.

Bare Chassis Testing

So how fast could the car go without any aerodynamic devices? I decided to base this project around my seriously quick Arrma Limitless RC Car. With a stock setup it can accelerate 0-60 in just 3.4 seconds. Safe to say it’s way, way quicker than my ‘real’ car. Some people have even got these same RC models to travel at over 160mph! It’s not really a car for corners, it’s one for straight lines which might actually make it more interesting to see how fast we can get it to corner despite its focus on straight line speed.

First off, I wanted to set a benchmark to see how fast the car could corner without its bodywork. This meant I removed absolutely all of the the stock bodywork, including the wings, splitter and defuser. I removed all of this stuff so I just had a bare chassis. Now the car was set up like the earliest Formula 1 cars that relied entirely on mechanical grip to go around a corner.

Mechanical grip the between tires and track pavement provided entirely by suspension and tires. These big fat tires are pretty grippy but are quite worn which should make testing a little more interesting. So how much would it slide around? Would the car be really unstable without aerodynamics or would it grip the road with ease? Time to fine out.

Aerobody Testing

Back in my workshop, I set to work building the new body of the car from lightweight and strong materials. Foam board, although not all that strong, is a good lightweight material that I usually use to make RC aircraft. It’s easy to work with and can be hot glued together. I made the wings from sheet aluminium, mainly to make sure they were super strong and could take a knock or two. Let’s face it, it was only a matter of time before testing the car to the limit resulted in a huge crash.

Now, I saw little point in doing this in a half measure, so I went ahead and made the hugest wings with the biggest surface area so I could get as much downforce as possible. Lift increases to the square of the wing area which means that doubling the size of the wings quadruples the amount of lift. It’s exponential. F1 car wings were quickly limited in size because they were ruled to be dangerous. We can go all out though, because who cares about making this thing safe!

The car was a little faster with the wings, but improvements could be made. I took this opportunity to have another look at the aerodynamics.

Firstly, with the front wing, as mentioned earlier, I had suspected the huge shovel like surface is probably creating a deadzone of low pressure which lessens the effectiveness of the rear wing. You can see here the way the air deflects and completely misses the rear wing. This means that the front of the car is being pushed into the ground, increasing front end grip, but the rear isn’t being pushed down as much, offsetting the balance. Ive read that the front wing is the most important part of a car as it’s what determines how the air flows around the rest of the car – so yes my wing is doing a pretty awful job at allowing the rear wing to do it’s job.

Secondly, drag! Look at all that drag! What’s happening here is boundary layer seperation caused by the extreme angle of this wing and the speed of the air traveling over it. The air should flow nicely around and under it, following the contour of the surface. Boundary layer separation occurs due to an adverse pressure gradient encountered as the flow expands, causing an extended region of separated flow. This results in a huge amount of drag behind the wing. Drag will cause the car to slow down in a straight line and reduce downforce.

I had a lot of comments about ignoring boundary layer separation being a key error in my experiments, but from my experience of flying model aircraft, huge wings at high angles of attack are still more effective at producing loads of lift at this small scale than smaller ones with less drag. I’m going to have to look into this more, and maybe this could have been something to investigate in this video. Maybe a future video could look to find the optimum wing for an RC car.

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Magnus Effect Boat (X2)

So, this is an experimental boat uses a really weird method of propulsion to move using only the wind and a spinning rotor. Here’s the video if you haven’t seen it yet.

What is the Magnus Effect?

The Magnus Effect is a super cool bit of physics. It’s commonly found being used in ball games, such as football or tennis, where a sports player curves the ball by introducing a spin on it. In my video I showed how when my friend Joe kicks a football, he uses the Magnus Effect to curve its trajectory

The Magnus Effect can be a very powerful force. I’ve mentioned in my Magnus Effect plane video that air can be dragged around and deflected to subsequently pushes a spinning object the other way. In that aeroplane video, I showed how I could create enough lift to fly an aircraft with this effect, so I decided maybe it would be fun to build a boat too! It might even be simpler and easy (but I was wrong)!

My First Attempt at Building a Magnus Effect Boat

I based my boat around a stable catamaran sailing boat. I printed out eight hull sections, which took around 12 hours of printing. Then I sanded the hulls and superglued them together.

I made sure these porous PLA hulls were both fully water tight by using this leak sealer spray followed by plenty of black spray paint, which I thought would make the boat look pretty cool. Next, I made some little connector pieces that could be used to join the hulls together with some 12 mm carbon tubes.

I gathered all of the other other major components I’d designed and printed and then essentially then had a big Lego kit to assemble.

The rotor mechanism uses a couple of bearings either side of a pulley that fit around another carbon tube. This was mounted to the front of the deck but could be moved about if needed later thanks to the standardised pattern of mounting holes I drew on these components. I might have to do this more in the future. It’s always helpful to have some build in ‘adjustability’ to my projects so I can play around with the setup of a vehicle at the test field without having to go back to my workshop to rebuild something and then go out again.

Next I printed a motor mount, installed a motor, built a rudder and tested everything thoroughly. With that, I could pack my things and then head off to find some water for a very first test run.

Learning From This Project

Key things to take away from the results of the testing shown in the video are:

I need a keel! Keels are key for boats like this to rotate around. Without one, you get a somewhat uncontrollable boat that you can’t keep facing at an angle against the wind.

It’s more about sailing than I realized. As with the above point, this was a hard introduction to sailing type vessels and I should have been more on it with thinking about this vehicle as a sailing boat rather than self powered.

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High Speed Rocket (X1)

Here’s some more info about the X1 rocket from my video from the end of last summer.

If you’ve not already, check out the video here!

This build is all about a high performance model rocket constructed using PVC pipes, 3d printed parts and a large solid fuel motor

I designed this rocket mainly using CAD and manufactured many of the parts from scratch.

I’ve built lots of rockets before but this time I made it dead simple to hopefully show you how you could make a high speed rocket from commonly available materials like this plastic plumbing tube and bits of plywood and stuff like that.

I designed this rocket to small and slippery. High speed vehicles need to be as small as possible to displace as little air as possible. This is why high speed RC aircraft are all as small as possible. As the mission of this rocket was to go faster than anything I’d built before, the X1 was therefore designed to have a very small frontal diameter meaning in will push through less air, have less drag, and be faster than any than many of my previous rockets.

The CAD program for simulations I used is called Open Rocket. I used it to figure out the speed and altitude of different designs by assembling body tubes and nose cones that have drag coefficients and mass. It’s super helpful as you can see how stable your rocket will be and how high it will perform using various motors. The motor I decided to use was a Cesaroni ‘G’ motor with a burn time of around 3 seconds. This engine provides 12.1kg of max thrust and it’s one of the biggest I can buy from a hobby shop online without being certified and doing a qualification. I predicted that this motor the rocket should accelerate to 730kph and top out at just over 840m up, over 100m clear of the maximum hight you can launch rockets in the UK. Here’s some info on UK model rocket laws if you want to get started with model rockets in the United Kingdom.

Building the Model Rocket

As usual I designed parts like the nose on Fusion 360, which has a free licence for hobbyists, before printing them on my 3D printers. Fins were cut from thin sheets of plywood on a laser cutter – I know, not everyone has access to one of these fancy things but you could cut fins by hand. The fins pushed into slots in the fuselage PVC tube, which is just a bit of old plumbing I found lying around, and then, yeah, everything was epoxied together.

Why did I add extra fins?

The finishing touch was to add a coat of bright orange paint. As this is the start of my ‘X’ program of highly experimental rockets, rocket planes and other vehicles, I thought I should take some inspiration from the real X1 flown by Chuck Yeager.

Launch Rail

This launch rail setup is new but I’m still working on refining this setup. I’ve been using the same 2020 aluminium extrusions to launch model rockets for over a year, now but they needed a proper base that’s easily adjustable for sloping hillsides and that sort of thing. For this reason I made an attachment for my favorite tripod which can be quickly adjusted at the launch site.

I’ve also been working on a safer and more refined electronics setup for launching larger, higher powered rockets. Essentially all you need to do to launch the rocket is pass some current through the electronic igniter, so up until now I’ve simply had a controller with a couple of switches that connect the rocket’s igniter to a LiPo battery (the same as I use to fly my airplanes). To move further away, much further away, I’ve combined the launch controller with my RC controller.

The Remote Ignition Switch

The RC controller is as simple as a brushed ESC connected to the throttle channel of my DX9 RC transmitter. The motor wires from the brushed ESC are connected to the igniter. This way, increasing throttle on the transmitter will pass current from the battery directly into the igniter. Now I can retreat all the way back to safety, arm the throttle channel and fire with a programmed switch on the DX9! Straightforward, reliable and effective.

Why Not Use a GPS onboard the rocket?

I’d been thinking it would be a good idea to add a GPS to get some accurate data from the flight. This worked quite well in my High Power Rocket Plane V1.

Now, here’s the thing: my previous GPS was destroyed by the recent rocket car fire so i’ve had to get creative with a replacement. I was thinking about building a GPS with an Arduino, as I’ve seen other people do, but I’d realised I have a GPS already that might do the job!

I have a GPS watch, so I thought I should be able to get some decent data from this, right? Sure, it will only capture data points once every second and be a bit limited, but I should be able to export the GPX files to Google Earth and have a cool overlay of the flight path.

I had the great idea of testing this out by strapping the pod under an RC Spitfire and taking it up on one day during an extremely windy day. Essentially, what I was trying to do was fly around in three dimensions to try and make a 3d path that I could then display on Google Maps, showing my flight path. Unfortunately, the flight didn’t end well. At least I had some good data, right? Well, no. It turned out I’d sacrificed the plane only to find out the watch simply recorded an X and Y and calculated altitude based on ground based position – which was extremely annoying to find out at the last minute.

Only X and Y, X and Y!

I need to come up with a better solution for the future, but for now I have no GPS, unfortunately.

If you’re wondering why I didn’t have a GPS tracker onboard, I’m afraid I couldn’t find one small enough for this rocket so used a Bluetooth tile which – yeah – are useless really. I would recommend them for finding your keys, but not for finding a rocket that could land 500m from the launch site when the range of the tile is but 40m!

X Series Naming System

So, this is the first vehicle of mine I’m naming with my new organizational system to help you and I keep track of these vehicles I make. I’ll be numbering each of them with the prefix meaning experimental. As this one is the first, appropriately seeing as though it’s orange, it’s called the ‘X1’. Hopefully you like the idea.

Concluding thoughts

I hope you enjoyed this one! Make sure to keep a look out for flight 2 of this rocket this spring (2022) when the weather improves.