So after a many many flights I had managed to break a couple of the canopy studs from the frame. I had been gluing them for a while but it got to the point it was time to replace the frame, which means stripping everything down and building it back up. While I was at it I replaced the tail boom assembly since the boom had split and vibrating pretty badly, as well as the main motor (brushed motor, had 100+ flights on it, many stalls before I was able to hit the TH switch, etc.). You can see the main motor replacement as a separate thread here: Nano CPX main motor replacement.
1-8) Follow steps 1-8 in the main motor replacement thread. Go ahead and remove the main gear before pressing the motor out of the frame.
9) Remove the rotor head and swash from the main shaft. Remove the two screws holding the head on the main shaft (careful, very easy to drop and lose these). Pop the servo-swash connector links from the swash, remove the left and right connector links from the servos, taking care not to turn the ball link ends on the connector arms (don't want to screw up the swash leveling at reassembly).
10) Lift the rotor head and swash off the main shaft by pulling at the base of the rotor head. Do not pull on the rotor blade holders, you may damage the spindle or the holders themselves. Pull on the link guides (circled) or more toward the hub between these guides.
11) If you haven't done so already, pull the main gear off the main shaft. Pull the main shaft out the top of the frame and bearings.
12) Unwind the tail motor wires from the canopy stud and pull the tail boom assembly from the frame. Grasp the tail boom firmly and the back of the frame which holds the tail boom, it will likely be in there pretty tight.
13) Remove the screws securing the rear (elevator) servo to the frame. Remove the servo from the frame. You will have to angle it out of there. Take care not to lose the servo arm once the servo is out of its cage.
14) Remove the right servo from the frame. This will free the control board and attached servos from the frame entirely.
15) Remove the left servo from the frame.
16) Only the main shaft bearings remain. They are only held in by friction, to pop them out with the tweezers or screwdriver from the center of the frame. Note the direction of the bearings for reassembly. They should have the bearing "guts" visible from the bottom and top, respectively.
That ends the tear down. If you're doing a straight frame replacement, then that's it, do it all in reverse (16-1) using the new frame for reassembly.
The rest of this post includes some additional items I did.
On the tail boom, the wires for the motor are kind of exposed and vulnerable in crashes. I found this out the hard way on my 120SR. I read of the idea of using heat-shrink to add some protection and it has worked great, so I do this on both the 120SR and nCPX. Alternatively, you could use a few layers of liquid electrical tape to make a less obtrusive protective layer. But be careful not to get any in the motor via any holes in the back of the motor.
The next mod directly addresses the issue that caused this whole effort: broken canopy studs. I read it on this forum, so props to whoever came up with it! Purposely cut the studs off at the half way point and reattach with heat-shrink (and maybe a dab of zap goo at the joint). I decided to try it first with my broken frame.
Found that the plastic of the frame is very easy to heat up. Have to shrink the tubing with quick passes and some blowing to cool off between passes, to keep the frame plastic from becoming, well, plastic.
I only did this on three of the studs. The one with the anti-rotation guide is very sturdy and doesn't really offer enough material to do a sacrificial cut. Also, instead of cutting clear through the stud, I left a very small bit of plastic connecting the stud halves. After heat-shrinking, I broke the tabs. This resulted in a very tight, yet bendable, connection to the outer stud. Tighter than the test attempt where I cut the outer part of the stud off entirely and then tried to reattach via the heat-shrink and a dab of glue. Also, if the studs should work loose, it will be possible to reapply new heat-shrink or use the existing shrink as a vessel for glue which should make a very secure connection to the stud end. All-in-all I really like this mod. Have yet to see if it works in practice (almost wishing for a crash?), but I have high hopes.
End with some reassembly pics:
With the heat shrink in place on the stud, the antenna no longer fits around the stud. Have to expand the coil a bit, careful not to bend the solder point connection much.
Careful on the rear/elevator servo wire. I accidentally ran it over the stud, it needs to go under.
Note the route of the main motor wire, around the left side and over the servo wires.
All done!
1-8) Follow steps 1-8 in the main motor replacement thread. Go ahead and remove the main gear before pressing the motor out of the frame.
9) Remove the rotor head and swash from the main shaft. Remove the two screws holding the head on the main shaft (careful, very easy to drop and lose these). Pop the servo-swash connector links from the swash, remove the left and right connector links from the servos, taking care not to turn the ball link ends on the connector arms (don't want to screw up the swash leveling at reassembly).
10) Lift the rotor head and swash off the main shaft by pulling at the base of the rotor head. Do not pull on the rotor blade holders, you may damage the spindle or the holders themselves. Pull on the link guides (circled) or more toward the hub between these guides.
11) If you haven't done so already, pull the main gear off the main shaft. Pull the main shaft out the top of the frame and bearings.
12) Unwind the tail motor wires from the canopy stud and pull the tail boom assembly from the frame. Grasp the tail boom firmly and the back of the frame which holds the tail boom, it will likely be in there pretty tight.
13) Remove the screws securing the rear (elevator) servo to the frame. Remove the servo from the frame. You will have to angle it out of there. Take care not to lose the servo arm once the servo is out of its cage.
14) Remove the right servo from the frame. This will free the control board and attached servos from the frame entirely.
15) Remove the left servo from the frame.
16) Only the main shaft bearings remain. They are only held in by friction, to pop them out with the tweezers or screwdriver from the center of the frame. Note the direction of the bearings for reassembly. They should have the bearing "guts" visible from the bottom and top, respectively.
That ends the tear down. If you're doing a straight frame replacement, then that's it, do it all in reverse (16-1) using the new frame for reassembly.
The rest of this post includes some additional items I did.
On the tail boom, the wires for the motor are kind of exposed and vulnerable in crashes. I found this out the hard way on my 120SR. I read of the idea of using heat-shrink to add some protection and it has worked great, so I do this on both the 120SR and nCPX. Alternatively, you could use a few layers of liquid electrical tape to make a less obtrusive protective layer. But be careful not to get any in the motor via any holes in the back of the motor.
The next mod directly addresses the issue that caused this whole effort: broken canopy studs. I read it on this forum, so props to whoever came up with it! Purposely cut the studs off at the half way point and reattach with heat-shrink (and maybe a dab of zap goo at the joint). I decided to try it first with my broken frame.
Found that the plastic of the frame is very easy to heat up. Have to shrink the tubing with quick passes and some blowing to cool off between passes, to keep the frame plastic from becoming, well, plastic.
I only did this on three of the studs. The one with the anti-rotation guide is very sturdy and doesn't really offer enough material to do a sacrificial cut. Also, instead of cutting clear through the stud, I left a very small bit of plastic connecting the stud halves. After heat-shrinking, I broke the tabs. This resulted in a very tight, yet bendable, connection to the outer stud. Tighter than the test attempt where I cut the outer part of the stud off entirely and then tried to reattach via the heat-shrink and a dab of glue. Also, if the studs should work loose, it will be possible to reapply new heat-shrink or use the existing shrink as a vessel for glue which should make a very secure connection to the stud end. All-in-all I really like this mod. Have yet to see if it works in practice (almost wishing for a crash?), but I have high hopes.
End with some reassembly pics:
With the heat shrink in place on the stud, the antenna no longer fits around the stud. Have to expand the coil a bit, careful not to bend the solder point connection much.
Careful on the rear/elevator servo wire. I accidentally ran it over the stud, it needs to go under.
Note the route of the main motor wire, around the left side and over the servo wires.
All done!
I'd edit the post but no option for it.