Before adding more parts to the fuselage it’s better to add the controls. Other builders informed me that some adjustments are needed to make sure the controls move smooth and this is easier now since the center fuselage is quite accessible now.
The control sticks with inspection documents:
The forward bushing fits perfectly but the rear not. The rear busing has exactly the same diameter as the aluminium tube.
With the desktop CNC I made custom made grinding tool from 18 mm MDF. It has a tapered diameter from 37.4 mm at the top to 37.5 mm at the bottom:
Next I glued some 600 grit to the MDF disc, with the sandpaper it has exactly the right diameter to grind the bushings:
Next I used some grinding / polishing compound and several grit sandpaper (600 – 3000 grit). The coarse and fine valve lapping compounds were both too coarse. Therefore I didn’t use that and first used the sandpaper, 600, 1000, 1250, 2000, 3000 and finally polished with scratch remove polishing compound:
The Alodine layer was removed by the sanding and polishing to I applied 2 layers Alodine with the Alodine pen:
I did some investigation about the Vesconite bushings. Some people say not to grease them, others say it can’t hurt.
So I checked their website
This is the answer:
I checked also the datasheet of Boelube 70307. It has no solvents in it that could hurt the bushing. To be sure if Boelube could be used to “grease” the bushing I contacted technical support from Vesconite. They confirmed Boelube can be used: “This is a very nice application! I fully agree with your method of thinking and I believe that the grease you used will work excellent in this application. You can just apply initial greasing upon installation of the bushes and then close it. It is not necessary for continuous greasing, as Vesconite is self lubricating.”
So I applied a little bit Boelube to the inside of the bushings and the bushings run super smooth now:
After installing the sticks to the fuselage they didn’t run smooth anymore. The bushings get squeezed by the aluminium brackets and these brackets need a bit opening with help of the Dremel tool. The alignment of the right stick was not perfect in line with the brackets of the rear bushing, this was easy to fix by bending the bracket. After several iterations the sticks move perfect now; they are not sloppy and move without any friction:
Here a video of the movement:
They need to come out another time so I can apply some primers to brackets where I did some grinding. Furthermore the locking rings need to get drilled and riveted…