Recall in the Overview section, I explained how I want to replace all phenolic bearings with actual bearings that could be bolted on and replaced. When I did the wing root rib layup, I knew this was going to be the case, but hadn't ironed out the details.
Note that most of the following pictures have the wings up-side-down on the benches.
First step was to figure out how much of the wing root I was going to have to mill out to clear CS132L weldment. (Page 16-14 through 16-16 in the plans shows this)
So I marked how much I needed to mill out...
And used the dremel to mill the fiberglass away...
Made sure I had proper clearance... of course, this was just an estimate until I could install CS132L bellcrank..
In order to install an actual bearing here, I needed something to bolt the bearing on to... so I decided to cut a 2"x4" plate of 1/4" birch plywood...
I placed it on top of the aileron torque tube hole and traced it out...
Using a dremel, I milled out a 1/4" deep pocket...
I then dry fitted everything up to make sure I had enough clearance for the CS132L weldment..
I temporarily ran a 3/4" tube down the aileron torque tube hole and made it coincide with the aileron's A10 tube...
I then dry fitted the bearing on and traced it onto the plywood plate...
Drilled out the holes...
Bolted on some nutplates on the backside...
To install the nutplates, I used #4 x 3/8" wood screws since I needed a flush surface on the other side...
The tip of the wood screw stuck out a bit, so I took a metal file and made sure they were flush with the surface...
Since the plywood plate was about to be micro'd in place, I stuck putty clay inside the nutplates to keep epoxy from getting inside...
Painted plain epoxy onto the surface...
Slurried the foam surfaces...
Applied micro all over the backside of the plate...
And installed it in place...
Prepregged 3 plies BID at 45... and used a brush to tuck it in place (all mating glass surfaces were sanded for a nice glass-to-glass bond)...
Peel plied and let cure...
Next day, I drilled out the holes (being careful not to drill into the nutplates threads)... and removed all the clay inside the nutplates...
I was then able to install the bearing and test fit CS132L...
Repeated this for the right wing...
Made sure the CS132L cleared...
I then removed the aileron...
And focused on CS151 (the torque tube that runs from the aileron to the wing's root)...
But to figure out what length to cut CS151, I had to install the aileron universal ball joint (MS20271-B10)
The Cozy Girls had already drilled CS152 tube with CS132L weldment... this is an issue, since I was not sure how I was supposed to drill through CS151 (the aileron torque tube that runs from the aileron to CS152) so that it would be in the correct orientation? But for the time being, I continued...
I stuck CS152 / CS132L through the wing root bearing...
I slid CS151 through the aileron torque tube hole until CS151 went over CS152 and hit the plywood backplate...
I then made a mark flush with the aileron root onto CS151.... but not so fast! This is NOT the cut mark...
The aileron root extends 1.90" inboard when including the A10 nub and universal ball joint...
So I made a mark 1.9" inboard of my original mark... but not so fast! This is still NOT the cut mark...
Recall that when I slid CS151 through the aileron torque tube hole, I butted it up against the plywood backplate that bolts the bearing... so I needed to cut CS151 a bit shorter so that it will not rub up against the plate... so I came an extra 0.25" inboard of my last mark...
I cut CS151 to length and reinstalled the aileron to make sure my measurements were correct...
Using my digital caliper's depth gauge... CS151 was exactly 0.25" outboard of the plywood plate.. PERFECT!!!
I then removed the aileron (for the 100th time!)... and drilled CS151 to the aileron's universal ball joint...
It was now time to drill through the inboard end of CS151 to mate it with CS152. Remember how I said the Cozy Girls had already drilled/mated CS152 with CS132L? See below...
I had two choices here: either A) reinstall the aileron with CS151 and use a marker through the bearing hole to indicate the 12 o'clock position when the aileron is at neutral, or B) scrap the Cozy Girl's CS152 and make my own.
I decided the marker method wouldn't be too precise and was afraid of ending up with CS152L weldment out of orientation. So I went with option B. I took spare 5/8" tube and mated it with CS151. I then reinstalled the ailerons.. and slide the extra long CS152 through the bearing hole...
I then slide CS132L through CS152...
I clamped the aileron in the neutral position... and rotated CS132L to be at the 12 o'clock position..
I then marked where CS152 needed to be trimmed...
I then removed the aileron... and brought CS151, CS152 and CS132L to my bench.. realigned the tick marks.. and drilled away...
I then reinstalled the aileron... and located the CS127 assembly... I used dummy aluminum pushrods for now but replaced them with steel rods later (see notes on the Overview section).
When I was happy with the movement of the aileron and CS128 bellcrank.. I match drilled through the wing's shear web using the flex bit...
Drilled all 4 holes and installed CS127 bracket assembly...
You are probably wondering how I built those amazing looking pushrods... ok, let me show you...
Here's a pic showing a steel tube next to a CS-50 insert...
I first measured 0.76" from the end of the steel tube (base of the insert)...
And punch marked it..
I used tape to temporarily hold the insert in place... and took it to the drill press... where I had a "V" channel cut into a 2x4...
I drilled through... and inserted a AN470AD4-10 rivet.. (for all pushrods aft of the firewall, CP#50 says we should use Cherry #CCP-42 rivets since those are made of stainless).
I clamped a rivet dimple die on my vice...
Positioned the rivet head onto the die...
...and tapped the other end of the rivet with a hammer until it mushroomed...
I then measured 0.93" from the end... and repeated the whole process...
Now the insert isn't going anywhere!
Might as well show the "quick disconnect"...
Pretty much the same process as before... measure, punch mark, drill, rivet... repeat...
Here I am showing how I would mount the heim joint first (with the insert)... and mark the tube flush with the insert's bottom shelf... this let me know where to cut the rod to length...
One pushrod at a time... eventually it all came together!
As I tested the ailerons out, I noticed that I wasn't getting full aileron travel to the left... and quickly realized it was because I needed to remove material off the fuselage inner wall (per plans page 16-6 view A-A says to "clear as required")... after I removed the material, the ailerons easily hit their 20 deg max travel.
I should note that the Cozy Girls CS128 bellcrank use AN4 hardware for the pushrods (instead of AN3 as indicated in the plans). This was a bit frustrating as I had already ordered XM-3 (AN3) heim joints for these. I had to order 4 new HM-4 heim joints to properly fit CS128. Since all threaded inserts use AN4 hardware, this was a minor issue. However, I should note that I also had to shave CS131 spacer down a bit and add AN960-416 washers, so that I could bias CS128 up a bit in order for the AN4 bolt heads to clear CS127 brackets properly.
And there you have it! The control stick now controls the ailerons! Woooohoooo!!!
No comments:
Post a Comment