The Start of The SAB KR84 Design and Build.

[RaavHimself]

Question to the experts on bungee launching.
I want to also incorporate a mounting plate in the inner structure to mount a hook for bungee launching, where do you put that hook? On the cg, forward or back of it?

Forward. The further the better

 

[skymaster]

How about testing it first with a hand launch to set the rates and expo. once it fly's do the bungy.

 

[Wildthing]

How about testing it first with a hand launch to set the rates and expo. once it fly's do the bungy.

There is no way you could toss it hard enough to glide test it, it's stall rate is around 30kmph.

 

[Wildthing]

Well picked up the plans today, cutting out double . @bracesport I ran out of drills 3D printer won't be turning off for a few days

 

[bracesport]

@Wildthing - luckily you can still fall back on the Coke!

 

[Wildthing]

Well one inner structure printed and assembled , hurry up 3D printer

 

[Wildthing]

Getting ready for the inevitable , dug out my snow shovel

 

[chris398mx]

Well one inner structure printed and assembled , hurry up 3D printer

View attachment 146137

I know the feeling of waiting on the printer. I am over 35 printing hours on my plane. The first one I crashed on its maiden after about 20 seconds. Now that's a poor return on investment!!! LOL

 

[Wildthing]

For a little added security for the ailerons I used the iron on covering . Adds a bit of strength and who knows how much strain these little pieces of foam are under. Red are for the 6S and black 4S . I thought of doing the newsprint but that just seems messy

 

[Wildthing]

I know the feeling of waiting on the printer. I am over 35 printing hours on my plane. The first one I crashed on its maiden after about 20 seconds. Now that's a poor return on investment!!! LOL

I don't think this one lasted 10 seconds , I did salvage one little piece, the knozzle .

I think each full setup for the jet, structure, canopy, mounts and nose cone is around 50 hours.

 

[Grifflyer]

I don't think this one lasted 10 seconds , I did salvage one little piece, the knozzle .

I think each full setup for the jet, structure, canopy, mounts and nose cone is around 50 hours.

Wow I was thinking around 20-25 hours...

 

[buzzbomb]

Getting ready for the inevitable , dug out my snow shovel

View attachment 146138

LoL. Where I live it gets pretty severe. I had to go high tech and full power. One of these is what I use!

I bet I shovel my snow faster than you do!

 

[Portlandbeginner]

Cool what 3d modeling software are u using fore the design??

 

[bracesport]

@Wildthing - maybe use the skid loader instead of the coke next time - seriously though, having two more of these beast show some major commitment to achieving a maiden - as always I love your work!

 

[Wildthing]

LoL. Where I live it gets pretty severe. I had to go high tech and full power. One of these is what I use!

View attachment 146149

I bet I shovel my snow faster than you do!

I am to old for that kind of manual labor. The older I get the more I hate winter.

 

[Wildthing]

Wow I was thinking around 20-25 hours...

Some of it is the quality of the printer, then how fine of a print you want. I could speed it up but then there are more flaws and simply just not as nice of a print. The 3DLabprint P38 I did (55" WS I believe) was somewhere around 90 hours.

 

[Wildthing]

Cool what 3d modeling software are u using fore the design??

I am using Rhinoceros

 

[Wildthing]

@Wildthing - maybe use the skid loader instead of the coke next time - seriously though, have two more of these beast show some major commitment to achieving a maiden - as always I love your work!

I decided to do 2 this time because the launch was cool and smooth (just the jet pilot/engineer screwed that up) because the frame minus the motor/battery and esc wasn't that bad for weight so I will use a lighter 4S setup in the one and 6S in the other. My 4S setup I think produces around 70 oz of thrust and I think I should be all loaded up around 40 oz.

 

[Wildthing]

Ailerons first, then the servos are mounted and then the outer top wing plates go on

 

[Wildthing]

Only one structure is complete so on it goes , 1 section to go on the second structure and it should be ready in the morning. With the structure in place then all the formers can go on. Which means I have to start cutting out the fuses soon.