Sonic Series | nnP-39

[andrej]

All the links to high-speed motors are dead, and the motors themselves are no longer in production. What motor is suitable for speeds up to 130 km/h these days? Will any 2206 2100 kv motor be suitable?
I'm planning to build a new NNP39.
Also, what do you think: should I choose 3mm or 6mm thick foam? Will the 3mm foam flex at speed?

 

[RickHunter]

All the links to high-speed motors are dead, and the motors themselves are no longer in production. What motor is suitable for speeds up to 130 km/h these days? Will any 2206 2100 kv motor be suitable?
I'm planning to build a new NNP39.
Also, what do you think: should I choose 3mm or 6mm thick foam? Will the 3mm foam flex at speed?

Yea. Those motors are discontinued. I believe the size for the sonic was a funjet 2825 1950kv. I don't think a 2206 will get you there for speed, but would work. Maybe a 2826 2200kv 40amp esc 3s setup might do it. It takes my swappable mustang to around 70mph(112km/h) with a 7x4x3 prop. Being this is a smaller plane, it should get you there.

Amazon.com

a.co

 

[andrej]

The 2206 2100kV on the nerdnicrc website says 70 mph on 3S and 90 mph on 4S. If those numbers are accurate, that's definitely enough for me.
I have an old Turnigy 2826 2200kV, I'll have to try it. Isn't the 7x4x3 overkill? I used a 6x4 propeller on one. For speed, a 5.5x4.5 would probably be even better.

 

[RickHunter]

Also, what do you think: should I choose 3mm or 6mm thick foam? Will the 3mm foam flex at speed?

At those speeds make sure to put a wing spar in. Nerdnic has a great aluminium one. Since your spar will be your strength, as far a thickness the 3mm will be lighter so I would go with that. Keep in mind the blueprints are for the Adam's or FT foamboard which is 4.7ish mm thick so you might have to modify (where the folds are ect....) the blueprints to fit whatever thickness foam you use.

 

[RickHunter]

I have an old Turnigy 2826 2200kV, I'll have to try it. Isn't the 7x4x3 overkill? I used a 6x4 propeller on one. For speed, a 5.5x4.5 would probably be even better.

Might be. I always forget that I live at high altitude, over 1600 meters, so I always bump up the props by a inch. The 6x4 was definitely slower for me. I use these cheap motors from the link, and they burn out really quick on 4s setup.

 

[andrej]

If I make the spar out of 4mm thick ply, won't it be too much? I can't find thinner plywood in my city.

 

[RickHunter]

I would think it should be okay. You might have to widen the channel to fit it in. The normal basswood he uses is about 3mm wide. I would pry not make it a super fast version with it though. If you have any type of hardware store around you, the aluminium spars he uses work great (it's what I used on mine) and are pretty cheap.

 

[nerdnic]

You should be good with 4mm. I didn't test that but the weight and strength will be close enough.