T E A M
Keeping the PFW photo thread short for pic discussion so I started this.
Welcome All!
After flying the Multiplex bipe Gemini for 3 weeks I hope I can give some positive pointers to those who are interested in this bird...
This is my Gemini setup:
Power: AXI 2814/20 840kV
at 106g it balances the plane nicely no additional modification is
needed as the fit is good
Prop: GWS 12x6 HD
This prop is very lightweight at compared to the for a APC 11X5.5E,
I've used it on the Acromaster before. The lightweight almost eliminate
the vibration problems I had with the APC.
Amp draw is about 23-25A (static) on a fully charged 3S lipo. Ample
thrust to climb vertically.
Alternative GWS 11x7 HD
This draws about 20-22A (static) on a fully charged 3S Lipo.
I think at 250W these GWS lightweight performs very well... Not too
sure about its toughness for higher power though. But then again I was
more concerned about the vibration problems, and these GWS do hold
some advantage here.
Battery: 3S 2100mAh 20C Lipo for 2 flights of 4 mins
50% most of the time, full bursts when maneuvering. 11.4V after flight, barely warm packs
Electronics: Airtecnic 9g servos all round (similar to HS-55 class)
The size/dimensions of these servos are just right. All OK
except a little buzzing for the rudder servos at full deflection.
I'm not going for 3D throws so I think they will be OK.
Hitec Electron 6 RX
good 'ol Electron 6, reliable and almost glitch-free.
CC25
I'm pushing a little near to the limit here, but I think with the
large chin cooling holes there should be more than enough
airflow. Plus CC are build tough and able to handle quite a bit
of over amps.
Flight test shows the ESC to be barely warm after flights, so I'll
keep it in.
Other Mods: Dubro Lite Flight Wheels
These are amazing shock absorbing wheels. My Acromaster
experience shows that the paved road I fly from causes the
plane to wobbly and not track staight during takeoff and
landing. This is because of the rough surface. Found out that
Elapor wheels are too stiff. The switch to dubro's totally
cleaned up the takeoffs and landings. The plane sticks to the
runway upon landing and hardly bounce.
FLYING:
My CG is at 80-85mm from the top wing's center-forward leading edge. The plane does basic aerobatic maneuvers well and is very comfortable to fly.
Takeoffs tracking is very straight in calm conditon. But tend to wind-vane 'coz of the large rudder when winds are stronger. Correction is easy though.
Once in the air, the 1kg makes the plane fly smooth and solid. This bipe handle the winds quite well. Flying downwind can gather speeds quickly. Upwinds tends to be a little slow. Maybe due to the extra drag by the bipe-configuration.
Rolls are lively without being too twichy. Unlike F3As and 3D-er the rolls are not very axle but will sink a little in the inverted position... somewhere in between a warbird and a formosa. I am actually happy about this... very realistic flying style.
Inverted flight needs a little "down" stick. I have the feeling that the 80-85mm CG is not at its limit yet, and may move CG back to 90mm to try pump up on the agility factor and hands-free inverts.
Knife edge flights with full rudder does have some roll coupling effect. I'm in the process of mixing rudder/ailerons for swee-swee knife-edges.
Hammerheads kicks are easy and smooth. Not the really tight types but the slow-mo ones. This bird has to be flown with momentum in mind. Not your regular yank-and-burn 3D performer.
Due to my limited elevator throws, harriers are not possible. Some mods to increase elevator may be required to allow for high alpha harriers... After which there's still that wing-rocking tendency to take care of for a happy harrier.
Landings are easy as the plane don't really tip stall. You know its too slow when the nose mushes over and some power needs to be added. With some headwind my touchdown runs is only about 10m. Fantastic for a 1kg bird. But don't be mistaken, its not really a floater. Total power shut down is not advisable as the Power-off sink rate can be quite high.
Bottom line... a happy, fun plane that is easy to fly, pleasing to the eye and tough to withstand the odd accidents and hanger rash.
That's it folks. End of my limited flight experience.
Cheers,
Leon
A Big thanks to Bro PacMAN and HDB for the wonderfull Pics.
Welcome All!
After flying the Multiplex bipe Gemini for 3 weeks I hope I can give some positive pointers to those who are interested in this bird...
This is my Gemini setup:
Power: AXI 2814/20 840kV
at 106g it balances the plane nicely no additional modification is
needed as the fit is good
Prop: GWS 12x6 HD
This prop is very lightweight at compared to the for a APC 11X5.5E,
I've used it on the Acromaster before. The lightweight almost eliminate
the vibration problems I had with the APC.
Amp draw is about 23-25A (static) on a fully charged 3S lipo. Ample
thrust to climb vertically.
Alternative GWS 11x7 HD
This draws about 20-22A (static) on a fully charged 3S Lipo.
I think at 250W these GWS lightweight performs very well... Not too
sure about its toughness for higher power though. But then again I was
more concerned about the vibration problems, and these GWS do hold
some advantage here.
Battery: 3S 2100mAh 20C Lipo for 2 flights of 4 mins
50% most of the time, full bursts when maneuvering. 11.4V after flight, barely warm packs
Electronics: Airtecnic 9g servos all round (similar to HS-55 class)
The size/dimensions of these servos are just right. All OK
except a little buzzing for the rudder servos at full deflection.
I'm not going for 3D throws so I think they will be OK.
Hitec Electron 6 RX
good 'ol Electron 6, reliable and almost glitch-free.
CC25
I'm pushing a little near to the limit here, but I think with the
large chin cooling holes there should be more than enough
airflow. Plus CC are build tough and able to handle quite a bit
of over amps.
Flight test shows the ESC to be barely warm after flights, so I'll
keep it in.
Other Mods: Dubro Lite Flight Wheels
These are amazing shock absorbing wheels. My Acromaster
experience shows that the paved road I fly from causes the
plane to wobbly and not track staight during takeoff and
landing. This is because of the rough surface. Found out that
Elapor wheels are too stiff. The switch to dubro's totally
cleaned up the takeoffs and landings. The plane sticks to the
runway upon landing and hardly bounce.
FLYING:
My CG is at 80-85mm from the top wing's center-forward leading edge. The plane does basic aerobatic maneuvers well and is very comfortable to fly.
Takeoffs tracking is very straight in calm conditon. But tend to wind-vane 'coz of the large rudder when winds are stronger. Correction is easy though.
Once in the air, the 1kg makes the plane fly smooth and solid. This bipe handle the winds quite well. Flying downwind can gather speeds quickly. Upwinds tends to be a little slow. Maybe due to the extra drag by the bipe-configuration.
Rolls are lively without being too twichy. Unlike F3As and 3D-er the rolls are not very axle but will sink a little in the inverted position... somewhere in between a warbird and a formosa. I am actually happy about this... very realistic flying style.
Inverted flight needs a little "down" stick. I have the feeling that the 80-85mm CG is not at its limit yet, and may move CG back to 90mm to try pump up on the agility factor and hands-free inverts.
Knife edge flights with full rudder does have some roll coupling effect. I'm in the process of mixing rudder/ailerons for swee-swee knife-edges.
Hammerheads kicks are easy and smooth. Not the really tight types but the slow-mo ones. This bird has to be flown with momentum in mind. Not your regular yank-and-burn 3D performer.
Due to my limited elevator throws, harriers are not possible. Some mods to increase elevator may be required to allow for high alpha harriers... After which there's still that wing-rocking tendency to take care of for a happy harrier.
Landings are easy as the plane don't really tip stall. You know its too slow when the nose mushes over and some power needs to be added. With some headwind my touchdown runs is only about 10m. Fantastic for a 1kg bird. But don't be mistaken, its not really a floater. Total power shut down is not advisable as the Power-off sink rate can be quite high.
Bottom line... a happy, fun plane that is easy to fly, pleasing to the eye and tough to withstand the odd accidents and hanger rash.
That's it folks. End of my limited flight experience.
Cheers,
Leon
A Big thanks to Bro PacMAN and HDB for the wonderfull Pics.
..keke...
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