Anyone tried some kind of a catapult to launch this bird? I don't have access to launch capable club members every day. Could be nice to have some device to launch myself.

I'm also interested in any design/plans for a bungee launch.

All you need is plastic plumb pipe and fittings. You will find a couple of threads about catapult launch using search engine. Just to get an idea...

I see the manual recommends MULTIPLEX Nano Pro MG digi4 servos, but these don't appear to be available in the USA. Anyone know what the best equivalent HiTec, JR, or Futaba would be?

Originally Posted by PeteB

I see the manual recommends MULTIPLEX Nano Pro MG digi4 servos, but these don't appear to be available in the USA. Anyone know what the best equivalent HiTec, JR, or Futaba would be?

Hitec HS-5065MG digital

Jürgen

Originally Posted by PeteB

I see the manual recommends MULTIPLEX Nano Pro MG digi4 servos, but these don't appear to be available in the USA. Anyone know what the best equivalent HiTec, JR, or Futaba would be?

I have put Futaba S3150 in my FJU. They fit almost 100% in the slots in the wings, and work perfectly at high speed

Thanks guys. I'll have a look at both.

Smoked my HET2w-25 today when trying to push it beyond 120amps on 6s...

Has anyone tried to mount a 36mm diameter inrunner in the Ultra?

Originally Posted by jeeeeeeright

Smoked my HET2w-25 today when trying to push it beyond 120amps on 6s...

Has anyone tried to mount a 36mm diameter inrunner in the Ultra?

You guys have the luxury of low temperatures.Check this out:
funjet on stereoids by thunb numb
https://www.rcgroups.com/forums/showthread.php?t=744411

Originally Posted by petranf

You guys have the luxury of low temperatures.Check this out:
funjet on stereoids by thunb numb
https://www.rcgroups.com/forums/showthread.php?t=744411

Mine were faster until it left the elevons behind on i full-speed pass. We radared it at 167mph on 6s1p220045c lipo, CC Ice 160amp esc and the HET2w25.

Originally Posted by jeeeeeeright

Mine were faster until it left the elevons behind on i full-speed pass. We radared it at 167mph on 6s1p220045c lipo, CC Ice 160amp esc and the HET2w25.

God mercy. Why guys you dont install hinges at the elevons with this speed. I was almost killed by this faillure by another guy. Now you know.

The 154mph from the thread i gave you belongs to a guy using a turnigy motor. The fj with the 36mm motor that thumb numb is building, has not flown yet. Test flights are expected this weekend.

Originally Posted by cfe7

Anyone tried some kind of a catapult to launch this bird? I don't have access to launch capable club members every day. Could be nice to have some device to launch myself.

Originally Posted by PeteB

I'm also interested in any design/plans for a bungee launch.

Originally Posted by petranf

All you need is plastic plumb pipe and fittings. You will find a couple of threads about catapult launch using search engine. Just to get an idea...

Unless you just want to build something, all you need is a short length of tubing or bungee cord, a stake and a suitable hook on your model. I bungee launch an unpowered Multiplex Twinjet and other models for "slope on a rope" flights, with sections of tubing from an old high start.

Originally Posted by jeeeeeeright

Smoked my HET2w-25 today when trying to push it beyond 120amps on 6s...

What did you expect? It's only rated at 50A for max efficiency.

http://www.wemotec.com/shop/product_...ess-Motor.html

jeeeeeeright,

I would be worried with 100A or close to it when after max power out of that nice HET motor.......but you put 120A in that motor, especially given this airframe's pisssss poor cooling airflow for motors!!!!!

I'm sorry for your loss.



Gryphon

Originally Posted by GryphonRCU

jeeeeeeright,

I would be worried with 100A or close to it when after max power out of that nice HET motor.......but you put 120A in that motor, especially given this airframe's pisssss poor cooling airflow for motors!!!!!

I'm sorry for your loss.



Gryphon

I saved the plane. Motor just lost power/magnetism due to heat. Oh and the solder on the plugs melted(!).
I knew it was just a question of time before it could not stand up to the increasing abuse anymore, but as I have a identical replacement motor (with a bent shaft from a unfortunate landing - just need to swap the shafts now) I wanted to see how far it would go.

I just upgraded from the standard FJ to the ultra, and I'm wondering if I should order a cheapo hobbyking 36mm inrunner just to test it. If all is OK I can always exchange it with a better one...