IMAC Double Build, Carden Pro 124" Extra 300 40%
- Thread starter orthobird
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- 40% airplane build thread imac
Just finished installing the servos and pushrod. I made the push-rods myself. They are 6-32 threaded rods from McMaster Carr. The Dubro Monster ball links are also 6-32. the screw going into the control rod is 6-32, and the opening in the ball link is for 6-32 threads. On the other side, I am using Air Wild Arms. Note, the center screw is not installed yet, into the servo output shaft. Waiting til I turn on the radio and begin to program it, but otherwise, the geometry of the linkage is set.
I still have to seal the hinge line, then the stabs are officially done.
I still have to seal the hinge line, then the stabs are officially done.
Rusty 73
100cc
You been busy , noticed the orange stabizler doesn't have those fibreglass supports for the servo mounting screws . You use them on the white stabilizer for the servo screws .Those servo arm look similar to the one MKS use for the eight series servo , larger output shaft ...
Those Jr servos most be pushing 500- 600 oz when running at 7.4 volts .Jr america doesn't show the spec for output or speed
Just a question concerning the ball linkage on the control arm , do you normally use the second hole from the bottom ?
How far from the center of the hinge line is the ball connected to the arm , one inch or 1.25" ..
Like the Caroline wing bags the yellow looks great
Those Jr servos most be pushing 500- 600 oz when running at 7.4 volts .Jr america doesn't show the spec for output or speed
Just a question concerning the ball linkage on the control arm , do you normally use the second hole from the bottom ?
How far from the center of the hinge line is the ball connected to the arm , one inch or 1.25" ..
Like the Caroline wing bags the yellow looks great
Hi Rusty,
how ya doing?
I have ordered the servo mounting washers that are carbon fiber. Once they arrive, I will install them on all of them. Just put those on for now.
The servo arms are from AirWild Hobbies. They are double truss arms, and there is a UNI-Hub. You can rotate the hub, 90 degrees at a time, so that you can get the splines lined up with the arm, so that at center, the arm is as close to center as possible!! Big plus. then if need be, can use transmitter trim to get it centered.
regarding my geometry, I like to set it up at 1 to 1, or, if greater than one to one, the greater distance is that from hinge line to hole on the horn, as opposed to center out put shaft to hole on arm distance.
SO, I am using the hole that is 1.5" out, and the distance from the hinge line to the hole that i chose is like 1.7" out. I did not want to use the 1st hole, even though closer to 1 to 1, i will lose travel, which I will not need, since this will be strictly for IMAC.
but, by decreasing the travel, I am increasing the resolution. SO when i use my transmitter to trim to fly level, it will be smaller steps. Even though, i can also do this with my transmitter, to make the trim steps real small.
you are correct, one of them, i used 1.5" arms, so it is on the 2nd hole. the other set of stabs, the servo arm is 1.25", so I am using the first hole on the control horn.
this is the specs on the JR NXB 8921 servos:
have no idea what the torque would be at 8.0 volts.!!
how ya doing?
I have ordered the servo mounting washers that are carbon fiber. Once they arrive, I will install them on all of them. Just put those on for now.
The servo arms are from AirWild Hobbies. They are double truss arms, and there is a UNI-Hub. You can rotate the hub, 90 degrees at a time, so that you can get the splines lined up with the arm, so that at center, the arm is as close to center as possible!! Big plus. then if need be, can use transmitter trim to get it centered.
regarding my geometry, I like to set it up at 1 to 1, or, if greater than one to one, the greater distance is that from hinge line to hole on the horn, as opposed to center out put shaft to hole on arm distance.
SO, I am using the hole that is 1.5" out, and the distance from the hinge line to the hole that i chose is like 1.7" out. I did not want to use the 1st hole, even though closer to 1 to 1, i will lose travel, which I will not need, since this will be strictly for IMAC.
but, by decreasing the travel, I am increasing the resolution. SO when i use my transmitter to trim to fly level, it will be smaller steps. Even though, i can also do this with my transmitter, to make the trim steps real small.
you are correct, one of them, i used 1.5" arms, so it is on the 2nd hole. the other set of stabs, the servo arm is 1.25", so I am using the first hole on the control horn.
this is the specs on the JR NXB 8921 servos:
- Torque: 363 (4.8V)/456 (6.0V)/562 (7.4V)
- Speed: 0.19 (4.8V)/0.14 (6.0V)/0.13 (7.4V)
- Dimensions (L/W/H): 1.55x0.82x1.59 in
- Weight: 2.96 oz
- Input Voltage: 4.8-8.5v
- MPU: 32 Bit
- Shaft Support: Dual Ball Bearing
- Comparable to DS8911HV and NX8921
have no idea what the torque would be at 8.0 volts.!!
Rusty 73
100cc
Hi Cam
Thanks for the explanation on how you like to set up your aircraft, I agree with the one to one ratio of the control arm length and the distance from the hinge line . Any greater distance on the aileron/ elevator arm positon, like 1.7 ' and you would get greater mechanical leverage but more sensitive in your throws and not as linear of movement more jerky of a movement .
Yes our TX(Jeti) we can adjust the percentage of trim output to the servo which i enjoy using to get the sweet spot for trimming and balance with the aircraft .
Carbon fibre servo washers never heard of them very cool , like to see a picture and where you got them ..
Those NXB 8921 servos have great spec's should hold up to all your practise time you do .
i wouldn't adjust the voltage pass 7.4volts , it could get pricey if they start smoking.!!!
Thanks for the explanation on how you like to set up your aircraft, I agree with the one to one ratio of the control arm length and the distance from the hinge line . Any greater distance on the aileron/ elevator arm positon, like 1.7 ' and you would get greater mechanical leverage but more sensitive in your throws and not as linear of movement more jerky of a movement .
Yes our TX(Jeti) we can adjust the percentage of trim output to the servo which i enjoy using to get the sweet spot for trimming and balance with the aircraft .
Carbon fibre servo washers never heard of them very cool , like to see a picture and where you got them ..
Those NXB 8921 servos have great spec's should hold up to all your practise time you do .
i wouldn't adjust the voltage pass 7.4volts , it could get pricey if they start smoking.!!!
Rusty 73
100cc
No Santa is only bring me seven MKS 599 and one 1250 servos for my Extra .
I Would like to get a new DS 24 but i haven't got to use my DS 16 enough in the last two years since purchasing for me to warrent buying the newest transmitter
How about you , will Santa be obtaining a new DS-DC 24 transmitter for your personal iMac usage ?
Santa has already delivered a Nikon D7200 camera with a 24-140 mm telephoto lens from a blackfriday sale .
I Would like to get a new DS 24 but i haven't got to use my DS 16 enough in the last two years since purchasing for me to warrent buying the newest transmitter
How about you , will Santa be obtaining a new DS-DC 24 transmitter for your personal iMac usage ?
Santa has already delivered a Nikon D7200 camera with a 24-140 mm telephoto lens from a blackfriday sale .
Jetpainter
640cc Uber Pimp
Are the carbon fiber plates you use like these from Align? I use them on my helicopters.
