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FT Explorer down thrust problem

#1
Hi, I am an inexperienced RC pilot and have just completed an FT Explorer build. I am running an A2212 1400KV motor with a 2200 mah battery and a 7X5 Prop with a standard wing (3channel). The CG is pretty well balanced and all appears good however the plane has extreme down thrust and will not fly. I have tried changing the motor alignment both up and down but still have the same problem. Obviously I have done something very wrong. Any suggestions or help would be greatly appreciated. Thanks.
 

kacknor

Build another!
#3
Have you checked the trim? Or, maybe added up elevator? Is the elevator parallel to the fuselage / wing? Is the rear fuse parallel to the nose? I've never built one but I'm thinking that if the nose/fuse/elevator aren't true, it will pitch down.

JD
 
#4
Thanks for the suggestions. The horizontal stabilizer is level, control surfaces are all centred. Holding the model with the throttle full on I can feel the rudder causing movement to the right or left but even with full up elevator it still wants to tip down. :(
 
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kacknor

Build another!
#5
Re-check CG then. Review all you can about setting CG first. Pictures might help. Sorry if I'm not being much help. Only a year into this myself. CG can do this. Wing angles can do this, low speed at launch can cause it. Does it pitch up first then dive? That's a stall.
 
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CrashRecovery

I'm a care bear...Really?
Mentor
#7
It sounds like it might be a tad nose heavy. Mine did that when I added the gopro with out moving the battery back to correct the CG. Even with full power and full up all it did was go into the ground.
 
#9
Thanks everyone,I really appreciate the help. I will try again after I rebuild the wing :). It sort of flew in a bit of wind and with a bit more enthusiastic launch until a barbed wire fence ate it. The CG was exactly where it is marked on the plan but I think from what I'm reading it possibly needs to come forward a bit. I am building with foam board available in Australia which is a bit heavier. I like the idea of a elevator throttle mix - that could help a lot. This is my first pusher build so I am learning a lot. will let you know how it goes after I get it back together.
 

RCLB

New member
#10
Hi, I have the same problem, and a member of the fórum, gregp, suggested a piece of foam under the leading edge of the wing as to elevate the angle of incidence, haven´t had time to try it, but he said that did the job. I bought the core kit so I scratch built the wings, maybe I got them a tad wrong. Hope this helps, have a great flight!
 
#11
Hi everyone, Thank you all again for all your help. The new wing is built and I have just had a very successful little session out in the paddock ( well away from fences :) )with my explorer. In the end I ended up increasing the motor angle up some more (3 mm ply under the bottom mounts), added a little elevator-throttle mixing and became more aggressive with my launching to get more initial air over the control surfaces. I also added a couple of degrees up elevator to the rudder which seems to be help. Once in the air this thing is so easy to fly. I need to adjust the mixes and a bit more trimming to get it perfect but as the daily wind has just started that will be a job for tomorrow morning. Final verdict - Couldn't be happier. :):)