2025 Speed Challenge - Telnar1236

[telnar1236]

Another approach that you can use is have 2 modes(launch and fly) where you put in (X) number of degrees of elevator in launch and you chuck it.
As it gathers speed, then flip to other mode (elevator 0 degrees) to do flight. I did that when I designed my flying wing with 64MM EDF that has no gear, until I solved my problem.

Even with that, it's a pain - this thing had 3 modes - a launch mode with a lot of up elevator, an intermediate mode with a medium amount of up elevator so that the transition would be smoother, and a speed mode with very little elevator at all. And even with all those modes, it was less than 50% likely this thing would get into the air on a given launch. That's the main reason I switched over to the launch dolly on my pylon racer - it means I can have my fingers on the sticks the second it gets in the air and it was enormously helpful in terms of having an easy takeoff

 

[telnar1236]

Seems like it is a gryphon.....but thats probably the last interesting thing about this airplane what is more interesting is that edf on that airplane.I didnt even know edfs could go 300 mph before seeing this airplane.

EDFs should be very good for speed on paper thanks to their flat thrust curves. The challenge is getting the thrust high enough and reducing the airframe drag enough that you can overcome the reduced thrust compared to props. Any idea what kind of EDF he was using?

 

[telnar1236]

Maybe this is wrong but I think that...a plane that shakes itself apart at supersonic speeds would have done so long before it has gone supersonic...

Look up transonic buffeting if you're curious as to what's going on here. It always occurs above the critical Mach number so with a 500 mph plane with a decently high critical Mach number, it shouldn't happen at all

 

[Houndpup Rc]

EDFs should be very good for speed on paper thanks to their flat thrust curves. The challenge is getting the thrust high enough and reducing the airframe drag enough that you can overcome the reduced thrust compared to props. Any idea what kind of EDF he was using?

Not to mention they don't have much torque so it takes longer to get up o speed..

 

[Piotrsko]

500 mph shouldn't be anywhere near sonic even on a way below zero day at 10,000 ft MSL. IF you're buffeting at 500, you got structure issues, control surface flutter or the boundary layer is getting triggered by bumps. What @telnar1236 said.

 

[Zoom Master]

Just saw this neat 90mm edf jet its looks like its based off The Mach Initiatives design but either way a cool airplane ! And it reached 134 mph !

 

[telnar1236]

Just saw this neat 90mm edf jet its looks like its based off The Mach Initiatives design but either way a cool airplane ! And it reached 134 mph !

Definitely a good looking and cool plane. 134 mph for a 90mm jet isn't too shabby but it's not too much to write home about either. He could probably get a bit more speed out of it by using a good duct for the EDF and a nozzle to improve efflux speed - the Freewing Zeus is capable of 150 mph on that same power system and there's probably room to optimize even that design further - I've never flown it, but I've seen it fly and it's very quick

 

[Zoom Master]

Definitely a good looking and cool plane. 134 mph for a 90mm jet isn't too shabby but it's not too much to write home about either. He could probably get a bit more speed out of it by using a good duct for the EDF and a nozzle to improve efflux speed - the Freewing Zeus is capable of 150 mph on that same power system and there's probably room to optimize even that design further - I've never flown it, but I've seen it fly and it's very quick

True but he could have gone even faster if he had done an actual proper dive from a greater height.

 

[telnar1236]

True but he could have gone even faster if he had done an actual proper dive from a greater height.

The thrust tube he put on it definitely helped a lot - now he's hitting 158 which is truly amazing for an EDF