Foam Glider FX7075
- Thread starter AdrianB
- Start date
quorneng
Master member
The FX707S is an excellent starting point to motorise. It is aerodynamically pretty efficient to start with
My own conversion is to a true motorised glider with a carefully faired in motor with a folding prop and even more important big flaps.
The other modification include a one piece wing but still held down by the original bolts. The fin and tail glued in place saving the weight of the original plastic fittings and screws.
The 24g LE2204 has a printed motor mount glued to the cut off nose.
A printed cowling matches the fuselage and the folding prop spinner. it includes a small cooling air intake.
The 10A ESC is mounted on the outside of the cockpit to ensure good cooling.
A Lemon 6 channel DSMX Rx is in the somewhat hollowed out cockpit.
All the servos are micro 3.7g type. The four flap and aileron servos are buried in the wings. The elevator servo is cut into the fuselage just behind the cockpit with nylon pull/pull lines back to the elevator. The rudder is fixed.
The ailerons have quite significant differential (more up than down) that virtually eliminates any adverse yaw.
The flaps have 3 positions 0,15 and 50 degrees. There is also an appropriate elevator compensation mix.
It flies very nicely and with a 1500mAh 2s it has an power on endurance approaching 30 minutes.
No thermal condition yet in the UK!
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My own conversion is to a true motorised glider with a carefully faired in motor with a folding prop and even more important big flaps.
The other modification include a one piece wing but still held down by the original bolts. The fin and tail glued in place saving the weight of the original plastic fittings and screws.
The 24g LE2204 has a printed motor mount glued to the cut off nose.
A printed cowling matches the fuselage and the folding prop spinner. it includes a small cooling air intake.
The 10A ESC is mounted on the outside of the cockpit to ensure good cooling.
A Lemon 6 channel DSMX Rx is in the somewhat hollowed out cockpit.
All the servos are micro 3.7g type. The four flap and aileron servos are buried in the wings. The elevator servo is cut into the fuselage just behind the cockpit with nylon pull/pull lines back to the elevator. The rudder is fixed.
The ailerons have quite significant differential (more up than down) that virtually eliminates any adverse yaw.
The flaps have 3 positions 0,15 and 50 degrees. There is also an appropriate elevator compensation mix.
It flies very nicely and with a 1500mAh 2s it has an power on endurance approaching 30 minutes.
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Thankyou all for replies but non off the links actually shows the assembly.
Not sure if it is standard but my kit came with no instruction at all. Just a box of loosely packed parts.
Also interested to see how the ailerons were activated as they have a dihedral in them and the wing looks too thin to accept a servo.
Not sure if it is standard but my kit came with no instruction at all. Just a box of loosely packed parts.
Also interested to see how the ailerons were activated as they have a dihedral in them and the wing looks too thin to accept a servo.
quorneng
Master member
You need instruction on how to assemble an FX707s! There were no instruction in mine either.
Note on mine the ailerons are positioned on the outer part of the wing so clear of the dihedral line. I just don't understand the why folk insist on using inboard or full span ailerons. A full size glider doesn't! The further out an aileron is the more effective it is.
On a plane this size I always use 3.7g micro servos which are thin enough to be glued ito the wing even that far out.
I have second FX707s that has the same aileron position, motor and folding prop but does not have flaps.It is about 20g lighter overall.
I hope this helps.
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Note on mine the ailerons are positioned on the outer part of the wing so clear of the dihedral line. I just don't understand the why folk insist on using inboard or full span ailerons. A full size glider doesn't! The further out an aileron is the more effective it is.
On a plane this size I always use 3.7g micro servos which are thin enough to be glued ito the wing even that far out.
I have second FX707s that has the same aileron position, motor and folding prop but does not have flaps.It is about 20g lighter overall.
I hope this helps.
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Thanks for that. No, I didn`t really need instructions for assembly, it was just annoying that i couldn`t find the video again.
I will follow your advice for ailerons, I had planned on using 3.7 gm servos .
quorneng
Master member
On mine I glued after installing the carbon tube wing reinforcement I glued the wing together as it made running the servo wires easier but did retain the 3 bolts to hold it on.
I also removed all the tail plane and fin plastic part and glued the tail & fin on permanently. It also saved a bit of weight right at the tail which tends to be a bit critical when you add control surfaces to a chuck glider.
Being a bit fanatical about aerodynamics I printed a close fitting cowling to match the folding prop spinner and the cut off nose.
The cowling includes a small inlet and two outlets for motor cooling.
Given the nose is made of foam and the canopy is virtually air tight I placed the 10A ESC on the outside wall of the cockpit to ensure it get adequate cooling.
You may also note the wing and tail plane have trailing edge "extensions". Printed in LW-PLA they take the 3mm as moulded foam edge down to a fine 1mm to create a better wing section. Don't know if it really makes any difference but with the prop folded it certainly glides very nicely. Ready to go it weighs 320g just 40g heavier than as chuck glider straight out of the box!
I also removed all the tail plane and fin plastic part and glued the tail & fin on permanently. It also saved a bit of weight right at the tail which tends to be a bit critical when you add control surfaces to a chuck glider.
Being a bit fanatical about aerodynamics I printed a close fitting cowling to match the folding prop spinner and the cut off nose.
The cowling includes a small inlet and two outlets for motor cooling.
Given the nose is made of foam and the canopy is virtually air tight I placed the 10A ESC on the outside wall of the cockpit to ensure it get adequate cooling.
You may also note the wing and tail plane have trailing edge "extensions". Printed in LW-PLA they take the 3mm as moulded foam edge down to a fine 1mm to create a better wing section. Don't know if it really makes any difference but with the prop folded it certainly glides very nicely. Ready to go it weighs 320g just 40g heavier than as chuck glider straight out of the box!
quorneng
Master member
On the blue one the ailerons are only on the outer section of the wing polyhedral and go to the wing tips but they are still adequate.
On the red one with flaps I actually flattened the outer dihedral so the ailerons could be bigger & longer to retain adequate roll control when flying very slowly using full flap.
For maximum performance as a glider (both my FX707s have folding props) I am sure smaller ailerons as far out as possible are better than the bigger inboard ones like those indicated by the wing moulding lines.
On the red one with flaps I actually flattened the outer dihedral so the ailerons could be bigger & longer to retain adequate roll control when flying very slowly using full flap.
For maximum performance as a glider (both my FX707s have folding props) I am sure smaller ailerons as far out as possible are better than the bigger inboard ones like those indicated by the wing moulding lines.
Have just assembled the glider and noticed that at the wing tips there is quite a bit of flex.
I am considering installing some thin carbon strip into the slot cut along the underside of the wing.
Did you do anything to strengthen the outboard as the ailerons would put a load on and I wondered if that was a factor.
I am considering installing some thin carbon strip into the slot cut along the underside of the wing.
Did you do anything to strengthen the outboard as the ailerons would put a load on and I wondered if that was a factor.
quorneng
Master member
I was not too worried about the wing flexing as long as it does not twist significantly at the same time.
That FX707s was intended to be a true powered glider so all that was needed was sufficient roll authority to be able to control it which it does. A "twinkle" roll is definitely not in its repertoire!
I always liked this picture of a full size glider wing bending.
Rather him than me!
That FX707s was intended to be a true powered glider so all that was needed was sufficient roll authority to be able to control it which it does. A "twinkle" roll is definitely not in its repertoire!
I always liked this picture of a full size glider wing bending.
Rather him than me!
Mr Man
Elite member
Looking at that you (anybody) might think that those wings are crazy strong. Actually, think about the power of the machine creating those forces…😳
