2026 Speed Challenge - Telnar1236

[Houndpup Rc]

And the 64mm plane is done - and I actually flew it this morning (hence the slight grass stains on the left wing). And now it needs a name if anyone has suggestions - I kept the demon name when working on it, but I don't think it really fits with how graceful this plane looks.
View attachment 258352
Had one good flight and another attempted one that resulted in minor damage that has already been repaired. On the good flight, I asked someone to hand launch for me, and it wanted to roll left a bit but otherwise hand launches super easily. Thrust to weight is better than 1:1 so it climbs like a rocket with unlimited vertical and top speed is pretty good though I don't think I'm quite hitting 140. It slows down relatively well to land too, since it can come in high alpha like any other delta wing plane. Weirdly, despite the speed, this is not that hard to fly so long as you can keep track of it, and it would probably be super nice if made with LW-PLA instead of normal PLA and a lighter power system.

It's also probably the toughest plane I've ever built. On the second flight, I tried to hand launch myself and it also wanted to roll left, but I couldn't correct in time, and it hit the ground going 50 mph. The picture above is from this evening, post-crash. The nose cone was completely shattered so I reprinted that, but the only other damage was some minor and easily repaired cracking in the vertical stabilizer (it must have cartwheeled) and a bit of cracking in the motor wire channel which doubles as a landing skid. When it went in I was sure I'd be reprinting the whole thing, but it was only about 15 minutes of actual work from me to get it back in one piece and most of that was filling and sanding some dents in the vertical stabilizer that did not need to repaired to get it flight-worthy (the prints took about 5 hours combined, but I could leave the printers to do their thing). To avoid future crashes from bad hand launches I'm building a launch dolly so I can do ROG takeoffs and not have to worry about it.

I had the GPS onboard, but forgot to start it recording, so I don't know how fast it went and honestly can't really give an estimate beyond quite fast. I'm used to planes getting twitchy or otherwise weird as they get near their top speed and this one doesn't really do that, so it didn't feel that fast, but it gets small quick, and I did a low pass where it suddenly became obvious that this thing gets up and goes. Filming this thing will be pretty tough since it's so quick and fairly small (about average for a 64mm jet - 35" long with a 22" wingspan) but hopefully I can some speed measurements and a good video this long weekend if the weather lets me.

Looks great!!👍

 

[telnar1236]

Looks a little bit like a Mirage fighter. How about "Fata Morgana."

I like the idea but it might be a bit too long to say on the regular - but I do like the idea of something mirage related

Maybe the "Saber" or "Falcon"?

Falcon might end up being the name - I already have the Super Duper Sabre and the Ghost which looks like an F-86 Sabre, so adding a Saber might get confusing. And falcon fits nicely on the tail fin.

The other name I'm thinking of is Cinquedea (a type of Italian short sword/dagger) since it's a broadly similar shape. But that's a bit long to fit on the tail fin and a bit long in general. However, it's also very unique

 

[Houndpup Rc]

The other name I'm thinking of is Cinquedea (a type of Italian short sword/dagger) since it's a broadly similar shape. But that's a bit long to fit on the tail fin and a bit long in general. However, it's also very unique

That sounds cool! You could also do rapier.

 

[RickHunter]

I like the idea but it might be a bit too long to say on the regular - but I do like the idea of something mirage related

Mirage 3d

 

[RickHunter]

That sounds cool! You could also do rapier.

Rapier is pretty cool too.

 

[telnar1236]

I think Rapier might be it

 

[Mr Man]

How about Vitesse? (French for speed)

 

[telnar1236]

How about Vitesse? (French for speed)

Between Rapier and Vitesse right now - may have to wait on the GPS reading to make my decision

 

[Houndpup Rc]

Between Rapier and Vitesse right now - may have to wait on the GPS reading to make my decision
View attachment 258359

Sounds good! Either way it looks great! BTW, are you gonna publish the files anywhere?

 

[telnar1236]

132 mph! On an old slightly puffed 30C lipo to boot. It won't break any records, but on only 870 W of power, it might be the most efficient setup in this competition.

This was the warmup flight for an intended set of speed passes with a newer 120C pack, so I think it's got a bit more in it - probably 140, maybe even more.

I also want to look at the impact of a couple of design features. My design approach to this was to CAD something up, run it in CFD, go woah, that's low drag, and then build it, so there is almost certainly room for optimization.

 

[Houndpup Rc]

132 mph! On an old slightly puffed 30C lipo to boot. It won't break any records, but on only 870 W of power, it might be the most efficient setup in this competition.
View attachment 258366
This was the warmup flight for an intended set of speed passes with a newer 120C pack, so I think it's got a bit more in it - probably 140, maybe even more.

I also want to look at the impact of a couple of design features. My design approach to this was to CAD something up, run it in CFD, go woah, that's low drag, and then build it, so there is almost certainly room for optimization.

NICE!! Any video? (Then I can put you at the head of the leader board😉👍)

 

[telnar1236]

Sounds good! Either way it looks great! BTW, are you gonna publish the files anywhere?

I'll probably post the v1 files in this thread tomorrow if anyone wants to experiment with it as well as step files of the entire design so that other power systems can be fit. V2 will probably be coming along with some aerodynamic optimizations and other changes in a week or so though

 

[telnar1236]

NICE!! Any video? (Then I can put you at the head of the leader board😉👍)

Unfortunately, none, I was going to try and film the passes with the higher c lipo but the launch dolly gave out during the second takeoff attempt so I only got the one flight in - hopefully very shortly though - since this thing is fairly easy to fly (for something so fast) and basically immune to wind I feel a lot more confident taking it out on less than perfect days

 

[Houndpup Rc]

I'll probably post the v1 files in this thread tomorrow if anyone wants to experiment with it as well as step files of the entire design so that other power systems can be fit. V2 will probably be coming along with some aerodynamic optimizations and other changes in a week or so though

Swweet!! Its 64m EDF right?

 

[Houndpup Rc]

Unfortunately, none, I was going to try and film the passes with the higher c lipo but the launch dolly gave out during the second takeoff attempt so I only got the one flight in - hopefully very shortly though - since this thing is fairly easy to fly (for something so fast) and basically immune to wind I feel a lot more confident taking it out on less than perfect days

Ah okay👍

 

[telnar1236]

Swweet!! Its 64m EDF right?

64mm Powerfun EDF with the bell mouth removed - it currently won't fit any other EDF. To remove the bell mouth, there's just a bit of tape you can cut to take it off so it's to easy to remove/replace. A more significant thing is that the wires from the EDF to the ESC have to be lengthened so they can run through the wire channel, but that can be done using separate wires and banana plugs so it doesn't need to be a permanent modification either. Personally, I just spliced some 16 ga wire in though (same as the EDF wires)

 

[Houndpup Rc]

64mm Powerfun EDF with the bell mouth removed - it currently won't fit any other EDF. To remove the bell mouth, there's just a bit of tape you can cut to take it off so it's to easy to remove/replace. A more significant thing is that the wires from the EDF to the ESC have to be lengthened so they can run through the wire channel, but that can be done using separate wires and banana plugs so it doesn't need to be a permanent modification either. Personally, I just spliced some 16 ga wire in though (same as the EDF wires)
View attachment 258368

Sweet! That's the exact model I have!😁

 

[telnar1236]

Sweet! That's the exact model I have!😁

I actually used the model you released on here in the CAD - modified with no bell mouth

 

[telnar1236]

Figured out why my predictions were a bit faster than the plane - almost 20% of the drag on this design is coming from the motor can on the EDF. On one hand this is frustrating since it's hard to change, but on the other hand, it does show just how streamlined this design is.

Unfortunately, my first though for a tail cone (mounted on struts) is only about 2% better than not having a tail cone at all, since the struts are quite draggy, but I think I may be able to improve that.

 

[Houndpup Rc]

I actually used the model you released on here in the CAD - modified with no bell mouth
View attachment 258370

Ah okay!😂👍 (I should work on making 3D files of some of the propdrove motors I have!)