Building a 570 MPH RC Plane Part II - Skin Assembly

[@TheMachInitiative]

We hope you liked this video! We have our final set of university exams in January, so we'll begin flight testing of the prototype once those are done. We're also working on another video breaking down the Kingfishers design in a little more detail which should help to answer some of your questions. Some FAQ: (1) The lines on the parts are from the filler we used to fill the gaps in the mould, while they look quite prominent, the part is actually quite smooth. (2) We chose fibreglass for its radio transparency. (3) We're using 5 layers of alternating 0/90 and +45/-45 woven plies. Thank you for your continued support - let us know what you'd like to see next in the comments! :)

[@alistair221]

I guess fibreglass is fine as long as you limit your manoeuvring! Do you plan to use an autopilot or manual FPV? Autopilot might make sense for planning big repeatable high speed runs if you can tune it for those speeds

[@brucebaxter6923]

That’s pretty cool. Could I ask why not mill a foam skin, glue in the bulkheads and spars then glass bag it?

[@Shelfka]

Super cool stuff! Years ago I used to build fast radio controlled aircraft, some achieving speeds of over 100Mph, using brushless motors and propellers, but this stuff you all are doing is so much cooler! I can't wait to see where this project goes!

[@richardm.newlands2417]

Excellent work guys, really high-quality composite construction! By the way, be sure to use a flexible extension on your Dremel when you start cutting carbon, cos carbon dust is conductive and kills Dremels. Rick Newlands, Spaceplane lead, Aspirespace engineering society.

[@TheMachInitiative]

Thanks for the advice - we’ll be sure to take it onboard!

[@ner0718]

I am astounded this channel has less then 10k subscribers. What an amazing project!

[@air-headedaviator1805]

Every time I engage with y’alls progress I’m shocked with the realization of the projects goals. Y’all are building a transonic aircraft thats RC. Its real ground breaking stuff

[@AeroFrics]

Thank you for spreading the passion for aerospace engineering. I make my own RC composite designs via similar processing methods and work in the aerospace industry as a composite manufacturing engineer so I can very well relate to some of your struggles. However, it's a huge joy to see young engineers coming together with an idea, getting their hands dirty and making something complex. You guys and girls are all doing a fantastic job, great design, clever manufacturing solutions and nice video editing. Well done! Greatings from NZ

[@thegps7197]

Nicely done, a few tips on hobby composite making with printed parts. Keep the tool parts open on the back side so when you pull a vacuum you allow the air out of the infill. I would typcially creat moulds as blocks rather than a nominal thickness in line with the part you make. When you pull a vacuum in a bag it can easily distort the tools. Might be worth halving your fibre weight and put 2 plies down so you can get a 0 and 45 degree fibre orientation.

[@TheMachInitiative]

Thanks for your advice - in answer to your last suggestion we’re using 5 woven layers alternated in 0/90’s and 45/-45’s to provide strength in different directions - with hindsight I probs should’ve mentioned this in the video!

[@איתיגיא-ח3ע]

@@TheMachInitiative but your mold definitely was warp in the Vacuum .

[@AstroCharlie]

Beautiful stuff! Good luck on your flight!

[@TheMachInitiative]

Thank you!

[@TheJoyBoi1]

Looking forward to see this in action, Can’t wait!

[@Cosmo95_]

Looking forward to seeing it in flight!

[@Brian-S]

Cant wait to see the rest of this amazing build. Great work fellas

[@jonahdrees9641]

Really enjoyed the video. Keep it going

[@TheMachInitiative]

Thanks Jonah!

[@NNNILabs]

yooo the mach initiative just uploaded!

[@cabanford]

The RC record is held by a *glider* at (give/take) 560 mph. Good luck 🍀👍

[@jlight7346]

Do you think a rocket powered RC plane would count in the public eye? It’s obviously not going to snag the jet powered record but just in general. Like some guy decides he wants to make his own mode rocket but launch it sideways and give it wings and a control system.

[@BadmintonSkills]

Cool project 👍

[@connormartin9644]

I have an idea: Once you guys have gotten the speed record set, It would be nice to release the 3D files for the smaller 3D printed EDF prototype, along with a parts list. I really want to make my own as it is just an amazing design!

[@viduraherath4008]

If you are confident in not crashing the aircraft or have funds to replace parts, i would recommend using foaming pla, or specifically bambulabs "pla aero" which is much lower density than other filaments when settings are tweaked. If lower weight is something you want, aero pla supported by some carbon fibre rods would be useful for such a thing. However ,being a foaming pla it is also quite bendy, so you might want to print the leading edge and front components separately with a more solid filament but make most of the rear and central fuselage using the foaming pla. If you plan to grant your aircraft high maneuverability, then i wont recommend pla aero since the force on the trailing edge in a tight turn would tear the wing. If weight isn't much of an issue and you want pure power to speed in a straight line, you might want to make a liquid fuel engine as you can get significantly more thrust, but that means your design will be heavier and at the size that the rc plane is, you will have very limited powered flight time. If you can launch it from another aircraft like a dive launch from a drone or just a high speed launch from another rc plane, that might help.

[@FrasseXD]

This i soooo cool bro

[@СержДигер]

Hi guys! Great project! What kind of airfoil do you use?

[@TheMachInitiative]

Supercritical

[@СержДигер]

@@TheMachInitiative airfoil selected from existing or custom? If it's not secret data, what exactly is the airfoil?

[@TheJo13425]

How long did it take you guys to come up with this design for the plane?? Would love to see a video (If possible) talking about the failed designs why they weren't quite right and the process as a whole

[@TheMachInitiative]

Sounds like a great video idea - thanks for the suggestion

[@omelletedelastreet9969]

I just wanted to know if your turbo jet engine is powerfull enough to accelerate your plane to 600MPH or are you planning to add an afterburner?

[@devanarayanan1243]

There is this russian guy called Ivan Markov who’s building 0.9 mach RC plane with afterburners and stuff

[@OMEGOOLIEBIRD]

Hey guys I love this project so much! Well done so far, it all looks really good! I see other projects on the same path and yours is by far the most likely to be a success. It is such a great mission for you young chaps! I wish you all the luck! I have been on a similar path and managed over 500kmh with both turbine and electric FPV models. I have some questions I would love to know the answers to! Where are you intending to fly it? (That has been my main hurdle) Who is going to fly it (I want to help!)? It will only be legal for about 3.6 seconds, so you will need to stretch the law, or get an exemption.. I chose the former as that type of exemption would be impossible for me to obtain. I see no problem as long as all preparations are made and risks assessed, there should be very little danger to anyone. Do you have a site in mind yet?

[@TheMachInitiative]

Thank you so much! I've been subscribed to your channel on my personal account for about a year, I loved your 509km/h FPV aircraft video - great to see you're interested in the project The logistical/ legal challenges are the biggest hurdle and is something we've spent quite a bit of time thinking about - we plan to fly at a private test range in segregated airspace, under the CAA specific category, which has resulted in us adding several redundant systems into the design including a 1ft drogue parachute that can deploy at 600 mph to prevent the aircraft from leaving segregated airspace if it goes off course (the goal here is not saving the aircraft, just bringing it down inside segregated airspace). We're currently working towards an application for operational authorisation, following some advice from industry sponsors, and we have a couple of possible options for test ranges. We would love for you to get involved - would you be up for a call? I'm in the middle of my final university exams at the moment, so I know it is a bit of time away but 25th Jan onwards would work best for me Cheers, Dan

[@OMEGOOLIEBIRD]

@@TheMachInitiative Hi Dan, it would be great to have a chat. Absolutely up for a call when ever suits you. Not sure how to share details here without doxing myself!

[@TheMachInitiative]

@@OMEGOOLIEBIRD That is great - really looking forward to it! If you send me a message using this page on our website: www.themachinitiative.com/contact it will redirect to my email inbox, then i can contact you without either of us having to dox ourselves! Let me know if that works for you

[@OMEGOOLIEBIRD]

Hey Dan, I hope you are all ok. Sad not to see an update on this project, I guess you guys are very busy with your studies. I did leave a message on your website, but have not had a reply. I would love to chat and find out more about the project and offer any help I can. Best wishes. Rupert.@@TheMachInitiative

[@TheMachInitiative]

​@@OMEGOOLIEBIRD Hi Rupert, i'm really sorry - I think there must be an issue with the "contact us" page on our website as i checked the inbox a few times to see if you'd sent anything including last week but it was empty. I'm really sorry about this, I've been really looking forward to having a call and v keen to see if there are any collaboration opportunities. Would you be able to send me an email at [e-mail] so we can organise a time to call? Best wishes, Dan p.s. we recently did an update on LinkedIn: www.linkedin.com/posts/the-mach-initiative_it-has-been-a-busy-month-for-the-mach-initiative-activity-7176320516486553600-YimU?

[@esahg5421]

Suborbital and then back again!

[@KainniaK]

Are you guys gonna build a scram jet and then use a helium ballon to bring it up to 15 or even 20 km of altitude to drop it? The terminal velocity up there is really high because there is not a lot of atmosphere so there is not a lot of drag. Keeping the dartjet stable will be the main challenge, and the forces on it will be enormous. But then if you fire up the scramjet at the right time you could break through the sound barrier. THe higher you go the lower speed you need to break mach 1 up there. It certainly is theoretically possible.

[@JoeMamma-c6c]

Good luck

[@Chris-Workshop]

is that thing full scale ? or a small scale EDF test version? what is the wingloading on that thing? hate to be pessimistic, but for all i see, this is never going to fly for more than a few seconds. also another problem i see is you're planning to fly this supersonic? how is this engine supposed to work in supersonic airflow? they are not designed for that. you'd need inlet ramps and stuff.

[@TheMachInitiative]

This is the full scale - you can see the Jetcat P300 Pro at the end We’re planning to fly at Mach 0.8 - the sharp drag rise at Mach 1 makes supersonic flight almost impossible with a micro-turbojet engine. Our S-duct inlet has been designed to decelerate the flow from Mach 0.8 to Mach 0.4 while keeping a uniform velocity profile at the compressor face. Our propulsion lead spent about 3 months doing a CFD study for this as part of his degree, in Feb one of our members will be doing experimental testing on the inlet to validate this cfd before flight, using the P300 Pro. Should also note a standard inlet will still work up to ~ Mach 1.3, it’ll just generate a bow shock on the front which is quite draggy - after that normal shock inlets and ramp inlets become more important. Nevertheless, we’re not going supersonic anyway. The wing loading is ~250 g/dm^2 which is ~120 more than the current world record holder. We would also prefer bigger wings but the drag increase from Mach 0.62 (current world record) to Mach 0.8 is about 70%, and aerodynamic optimisations will only get you so far. To reduce drag we have to make our wings smaller. The wings do have some wing tips not shown in this video that make them slightly larger than you can see there. We’ve consulted a high-speed micro-turbojet pilot during the build, if we get the aircraft up to speed (100 mph+) quickly it will be stable to fly, which having a 3:1 thrust to weight ratio and a pneumatic catapult helps with. Our stall speed is ~50 mph which is high, but not impossible to land. The beauty of the delta wing is it generates vortices that increase lift at lower speeds and enable it to fly at high angles of attack.

[@Fold-103]

When will you guys be releasing another video on the progress?

[@TheMachInitiative]

Soon!

[@Fold-103]

@@TheMachInitiative awesome!

[@anotherinternetaddict]

Any updates. When are you flying? 😊

[@TheMachInitiative]

We have already flown an electric prototype, main Kingfisher will fly in July. We have about 4 videos recorded and awaiting editing for a regular upload schedule over the summer, first video is imminent - WE HAVE A LOT TO SHARE!

[@wololo10]

Guys the KingTech K-320G4+ has 32 Kg of thrust with the same diameter

[@TheMachInitiative]

That is quite interesting - thanks for sharing! The K-320G4+ wasn’t an engine we considered during our turbojet selection about a year ago - we’ll stick to the P300 for now given we already have it and there’s lots of data available, but the K-320 could be a cool upgrade in the future!

[@wololo10]

@@TheMachInitiative you're welcome! Good luck with the project

[@Catfoolyou]

What engine are you guys using?

[@TheMachInitiative]

Jetcat P300 Pro

[@PSimonsen]

Since you wan't build the fastest, what is currently the fastest ? What record are you trying to break.

[@daviddavids2884]

fyi a jet engine (or edf) NEEDS to have forward-facing air inlet(s). in part, this is so because if inlets are (only) located where laminar flow is dominant, as airspeed increases so will the tendency of the air to flow past the inlet(s) without entering. proof: just look an Any type of normal jet aircraft design.

[@jlight7346]

They’re not doing anything serious with the EDF, as they explained in the video. They just need it to have a bit more thrust to make it easier for them to test the avionics before they stick it all in the final airframe.

[@kenenasfayera3158]

There talk is interesting

[@Fatpumpumlovah2]

think yall need watch some Ramy RC on building from 3d printed molds lol...

[@protator]

Input shaping ... no? So you enjoy sanding PLA,huh. No sanding blocks either? So you just hate smooth surfaces then?

[@hanni4795]

Why use fiberglass instead of carbon fiber

[@TheMachInitiative]

Radio transparency - carbon fibre is conductive, so you can't put antennas in a carbon fibre wing

[@hanni4795]

@@TheMachInitiative Ok i use carbon fiber in my fpv setups it dosnt block my radio link

[@richardm.newlands2417]

@@hanni4795 You've been lucky so far!

[@Fold-103]

@@hanni4795 its just for good measure especially when you are flying at almost the speed of sound.

[@Zoldlike]

@@hanni4795 And you probably have not enclosed your vtx / receiver completely in carbon fiber, have you? Normal quads have some open space around the receiver/vtx through which radio can go trough.

[@null2470]

Probably should have flown it first.

[@Fatpumpumlovah2]

sanding sucks? soys.

[@jamesjross]

where you up to?

[@TheMachInitiative]

We have already flown an electric prototype, main Kingfisher will fly in July. We have about 4 videos recorded and awaiting editing for a regular upload schedule over the summer, first video is imminent - WE HAVE A LOT TO SHARE!