Cozy
Chapter 13b - Rudder pedals, nose lift, etc.
Rudder Pedals
Much later I did Chapter 16, control linkages, and ordered my rudder pedals from Dennis Oelmann. With a nudge from Wayne, I found the installation instructions in Newsletter #64 and set to work. After getting some input from mail list members I made two bearings from phenolic and decided to mount the master cylinders in the middle. In preparation for fitting the rudder pedals I removed the canard and cleaned out all the various parts I'd been storing in the nose. The last item I removed was the Nose strut. As I turned around to put it on the bench, I saw, out of the corner of my eye, that the nose of the plane rising rapidly. I'd inadvertantly done a weight and balance test. I turned around, caught the nose at head height (just before the winglets hit the side of the patio) and gently lowered it back down. I put the strut back in and it stayed down. I put 20lb of lead in the ballast compartment.
I positioned the rudder pedals about 2 inches aft of vertical (I'm not very tall) and held the Matco master cylinders in place to get the position for the supports. I also cut an aluminum backing plate to hold
the reservoirs. Once everything was ready I floxed and glassed the nutplates for the pivots, the master cylinder supports and the phenolic bearings. When this cured I decided to paint the inside of the nose before fitting all the parts. I tried the "stonecraft" textured paint and didnt like it at all. I wiped it off before it had chance to dry and used a white latex based enamel instead.
[Important note: See footnote on the brakes for information about why the drawing in newsletter 64 is wrong, and the how laydown master cylinders should be installed
Nose Lift
After much thought and analysis I finally decided that, while fine on the patio, my Sears tool trolley was NOT going to cut it at 70 kts on a concreate runway. I decided to get a proper nose wheel. I looked at the various nose lift units available and liked the one from Jack Wilhelmson best. It takes up less room than Steve Wright's, and I've come to trust Jack's workmanship. While ordering from Jack I also got the MKNG6A roller bearing so I won't get the wear problems associated with the plans bronze bushings.
I'd ordered the nose strut from Featherlite when I got my main gear. I got my MKAA axle and MKNG4 bracket from Ken Brock. I've complained about Brock parts in the past, so I was very pleased to see that these items look excellent. Jack Wilhelmson's nose lift and MKNG6A bearing arrived, so I decided it was time to assemble my nose wheel. I finally found the wheel, tire and tube (bought 18 months ago) on my top shelf and started to insert the tube in the tire. The tube had a line where it had been folded. As I moved the rubber the line became a slit. The rubber had literally disintegrated. Wow! I'm glad it wasn't just a weakening that I might not have noticed. I called Wicks and ordered a new tube.
I shaped the strut just a little it to fit nicely inside the MKNG4 and NG15, then sanded and did the 2 one BID layups. Next the 1/4 inch aluminum plate that fits under the NG6A. I swear its not possible to drill 4 holes which are aligned perfectly with 4 existing holes. There's always going to be at least one that wants to be "off a bit". In my case it was two. I struggled for a while and finally got a good fit. Next the steel NG3A (from Jack) and the NG15 (from Brock) went on. Jack also supplies a steel foot which replaces the NG2 plate. (I later decided not to use this item and used the NG2 plate.) I assembled and floxed everything and came to the big moment - lets see what the plane looks like with a nosewheel. The NG6A plus two small washers supplied with it, and two large washers per plans fit EXACTLY inside my nose. Wow. Usually things are a bit loose, or a push (with the rubber hammer) fit. This was an 'engineer's fit" if every I saw one.
Working under the plane wouldn't have been so bad, except that our sewage system decided to fill up again. Those who've read about earlier problems with this seemingly unrelated system (Chapter 21) will understand that the normally plugged overflow hole is right underneath the nose of the plane. Getting the "Rocket Rooter" guys out again would be a real pain. I washed the patio down with the hose, hoped that the system would drain gradually on its own, and pressed on. I test fitted the NG6A before fitting it to the strut, then floxed everything together and let it cure in place to be sure of good alignment. Once this cured I removed the strut, added the NG15, steel foot, wheel and NG3A. Putting the completed strut back in the fuselage took a while. I discovered that the 1/4 aluminum plate was binding on the forward edge of the hole. 10 minutes with the dremel and some deft poking of the washers with a screwdriver and bingo, the bolt slid through and the strut was installed. I was a bit puzzeled by the mounting holes for the actuator plates.
The plans relate to retro fitting the manual system. It would help if there was a section directed at original equipment on a new plane. When I made the NG30's I did not have the NG50 to match drill the holes with, so I left out this step in the plans. It was hard to tell exactly where the hard points were until I thought to read my own web page and look at the pictures earlier in this chapter. When I fitted the nose lift actuator plates I started per Jack's item 1, page 3 and used the 'second back hole' in NG 30 for the bottom (predrilled) hole in the actuator plates. This placed the pivot bolts approx where they should be per Jack's plans. Next I drilled the top hole to match the plate with 3/8 edge clearance. So far so good. I now need to drill hole 2, but as I look at the Cozy plans it doesn't seem as though there is a hard point at this position on the right side. Cozy plans page 13-2 fig 8 say to make this hard point on the left side only. I presume I need to retrofit a hard point at this location. I asked Jack about this and he replied :
You are correct about this hole needing a hard point. I assumed everyone put
hard points at all four hole positions so that there would be no left right
confusion in the NG30s. I did it this way so I assumed everyone did. It is
very strange that after delivering over thirty nose lifts, no one has
complained about this before. I will change the installation directions.
I wondered if other builders might have missed this and installed one of
the nose lift bolts through foam.
Jack replied:
You maybe right. However, The hard point is there to keep the bolt tension
from collapsing the foam. This should be evident when they tighten the bolt.
Anyway, I am sure that the shear loads from lifting a heavily loaded
airplane can be carried by five .25 d AN bolts. The nice thing about
composites is that when one point flexes the other points pick up the load
long before that one point fails. Therefore all the load points must fail
together. I may send out a notice to my customer list to inform them of this
oversite, just to be safe. A hardpoint could be added from the outside of
NG30 without removing the actuator if the builder felt that it was needed.
Looking again at my pictures of the NG30's it looks like I did make four hard points on both NG30s, but I'll check carefully when I install the last two bolts.
Another minor issue was that Jack's plans say to use the 'original bolts and spacers'. I don't have any original parts and I couldn't find a spec for the NG14 spacers in the Cozy plans. I asked Jack about this and he advised that two NG14s are used. They are .5" od and .25 ID aluminum. They serve to stabilize the NG30s from flexing left or right. The other holes can use bolts without the spacers the same as the manual retraction mechanism. He could supply them, but I found two perfect AL pieces that were supplied for the elevator control quick attach points which I never used.
The Klutz strikes again
Rather than describe what happened next, I'll simply include my February 4th letter to Jack Wilhelmson:
Hello Jack,
You must think me a serious klutz! I seem to have broken just about every part you've
sent me. Well, last night I struck again. I was fitting the manual retract rod, and
decided that the hole in F22 needed to be a bit bigger, so I removed the bar from
the union and drilled the hole a little wider. Unfortunately my drill poked through
a little too far and destroyed the rubber jacket on the union which I'd left in place.
Duh! I have an identical union left over from the controls, but I cant seem to get
the hex fitting out. What's the best way to fix this? Buy a replacement modified
union from you, send you my new union and have you modify it, or is there a way I
can get the hex fitting out of the old one and modify my union myself?
But it gets worse..... read on.....
After this fiasco I was messing with the strut cover. I removed the bolt holding
the nose lift unit to the strut to fit the strut cover over it when I noticed that
the unit was restricted in its travel. I pushed it a little harder to get the cover
over the tube and, suddenly the restricted travel went away. Yes. You guessed it,
the travel was being restricted by the manual retract bar and the hex stud has broken
off. Double Duh! Is this something I can retrofit a replacement, or does the unit
have to come back to you for repair?
By the way, the good news is that the electrical nose lift is in and working
beautifully. I like it a lot. The wiring took me all of a couple of hours. I particularly
like the fact that I don't need a big hole in F22. Also, the fact that the spring
is enclosed in a tube means that I can seal the nose strut cover by fixing a
sliding piece of cured epoxy to the nose lift tube thus closing the hole in
the cover. Neat.
Please let me know how to proceed regarding the two problems above.
Jack replied the same day. Kindly he didn't comment on my amazing ability to break stuff.
Sorry to hear you are having problems, anyway I am sure I can help.
First:
The U joint boot damage can be repaired with some RTV. In fact the joint
will probably last the life of the aircraft if the boot was completely
missing. The boot protects the joint in hostile environments and this
environment is not very hostile.
If you want to replace the joint with the one you have, you can send it to
me and I will install a new hex in it. The hex in the other one is pressed
in and is not removable.
The other problem sounds more serious. I assume you are talking about the
hex shaft coming out of the top of the gear box. You actually broke it, or
did it come out of the housing? Look at it and see if it has TORX shape on
the "broken" end. If it does it came out of the housing. It is held in with
a snap ring, which is probably still inside the housing. In any case the
important question is: Is there any damage to the gear box housing top where
the hex shaft comes out? If not, I will send you a new hex shaft with a snap
ring installed and you can remove the housing top by removing the four
corner screws and install the new hex shaft. This is about a ten min. job.
If the housing is damaged, remove the housing top by removing the four
corner screws and send it to me.
Best Regards
Jack Wilhelmson N711CZ
www.EZnoselift.com
I thought I'd made all the major mistakes you could make with a nose lift. I missed one.
The next job was final finishing of the bottom of the plane. While doing this I discovered one more important thing you shouldn't do with an electric nose lift.
Kittens
At around this time our unfaithful cat, General George Patton, sadly died. After a few months, we got two new kittens, Harley (because of the way she purrs) and Grey Cat (because somehow she rejected all the names we tried out on her). I still find the General's footprints in my micro here and there. The Kittens are not allowed on the patio. (yea right! - I've since noticed scratches in my Zolotone and kitty footprints in my primer)
Wiring
Jack's nose lift plans cover all the essentials, but when it comes to the wiring I came across the sentence "Wiring is left to the individual builder". There's a wiring diagram, but that's it. Hmmm. Fair enough, I suppose. I'ts not Jacks job to teach me how to do airplane wiring. Just like the Cozy plans, there are many points at which you have to go through a learning curve before the words and pictures make sense. I dug out Bob Nuckoll's book and figured out how to crimp the leads to the jacks provided. Actually Jack has done an great job of prewiring with all the wires cut to length and labeled. I ordered the nose lift prewired for the auto retract system so there are quite a lot of wires. I routed the wires. Since I didn't order the auto-retract unit yet, these wires were routed to where this unit will go (on the side of NG30) and taped out of the way. It only took me a few hours to get everything hooked up. I don't have all the fancy airplane electrical parts yet, so I picked up an automotive fuse block from AutoZone, put a 12 volt car battery in the back seat and wired the positive to the fuse block. Using a 10 amp fuse (I won't make that mistake again) I connected to the ground and positive leads of the nose lift and pressed the button for the first time. Cool! The gears goes up and down very smoothly and stops just where I need it to stop. Now I get to add this feature to my airplane tour.
I noticed that yellow 'up' light stays on permanently when the gear is up, even if the switch is set to off. This seemed wrong to me, but Jack says thats the way it's supposed to be. I'd like to change the wiring so that off turns the light off, but I'll leave this for now.
Manual Extension - 40 degrees
Much later, once the bottom was painted, I turned my attention to the nose-lift manual extension again. I decided that I wanted the hole much lower than is allowed by one U joint. I contacted Jack and he offerred to add his 40 degree angle bracket to the nose lift cover while giving me credit for the two U joints I already owned. He even offered to replace the boot on one of the U joints which I'd damaged. I removed the nose lift, unscrewed the cover and mailed it off to Jack with a check for the modifications. A few days later it came back with the two U joints mounted on a braket. I filled in the old hole with foam and repaired both sides with 2 ply BID and 2 ply UNI. Next I cut a new hole in F22 to accomodate the U joint and removed 3 inches from the rod which goes through the dash. The mechanism moves when the gear is lowered and raised, so I had to elongate the hole a bit.
Manual Extension - placing the socket in the dash
The hole ended up being about 1 inch in diameter horizontally and 1.5 inches vertically centered about 2.5 inches from the top of F22. Now the manual extension socket is located where I want it - below the main panel on the vertical center console. If you don't want the manual extension in the middle of the radio stack, the 40 degree bracket modification Jack sells is an excellent, and essential, solution. I painted all the steel parts to avoid rust and reinstalled the nose lift. Finally I lowered the gear manually using a ratchet from the cockpit. It takes a while, and requires quite a strong pull on the ratchet, but it does go down. Not something you could do easily on final approach. Note - you'll see in the picture that the Florida humidity has gotten to the sticky label provided with the gear switch panel. I'll be making new labels to match the rest of the panel anyway.
Gear Doors
It seems strange to me that the plans don't allow for gear doors. It just doesn't seem right to be screaming along at 200 kts with a big hole in the bottom of the fuselage. I checked Wayne Hick's site (See! I do read it) and studied his hinged doors again. Shouldn't be too hard. I snapped a chalk center line down the fuselage and marked out the cuts per Wayne's dimensions. These are;
The hole cut into the bottom of the plane is:
15 and 5/8th inches long
6 inches wide at the forward opening
5.5 inches wide at the aft opening
The hole starts 2.25 inches aft of the forward edge of F22.
The hole is not cut square. I rounded the corners to 0.5 or 0.75 inch
radius.
Since the gear doors were formed from the bottom skin,
each door is 15 and 5/8th inches long,
3 inches wide at the front and
2.75 inches wide at the aft end.
I cut out the nose wheel door according to the above dimensions, then started thinking about the long door that covers the nose strut. After some thought I decided to buy AeroCad's prefab strut door while ordering the nose wheel cover. (Wow - does this mean I can call it an AeroCanard?). When these parts arrived I decided I liked the nose wheel doors that came as part of the piece. The doors have a slight reinforced bulge in them to accomodate the tire. This saves having to cut the "notch" in F22 back any further, and gives the doors more strength.
The only problem was that the hole in my fuselage didnt match the Aerocad doors at the front because I'd already cut the hole per Wayne's suggested size. No big deal. I patched the hole as needed with foam, micro and 2 ply BID, cut the doors and shaped them to fit nicely inside the hole. Next I bondoed the strut door in place and added a little extra fill around the sides to get it flush with the gear retracted. The shape down there needs a little thought because you have that big square of 1/4 aluminum sticking out below the NG6A pivot. I'm pretty sure my NG6A is located correctly and this plate was 1/4 proud of the fuselage surface with a 1/4 gap all around it.
I covered the center of the hinges with duct tape, then riveted them to the doors. I kept the hinges at a right angle to the doors to ensure 90 degree travel. Following Jeff Russels advice, I dug out the foam, then floxed and riveted the hinges in place against the upper side of the fuselage floor. Emulating Wayne Hicks, I put 1/4 inch birch stiffeners in the edges of the gear door opening. Once the hinges had cured with the doors in place and closed I removed the duct tape and voila - doors.
The spring
Wayne tells us on his site that a screen door spring is used, but he doesn't tell us how he fitted it. Hmmm. Maybe he hasn't fitted it yet. Anyway, I decided on two aluminum plates, each with a small hole for the spring to "curl though". With the spring cut to length and curled through the holes in the plates, I floxed and rivited the plates to the doors. Just for good measure I added a little more flox and two ply of dry BID (this soaks up epoxy from the flox and adds some strength) to anchor the plates to the doors. I covered everything with plastic (as usual) and squeezed out the excess epoxy/flox.
Next day I trimmed off the glass and retracted the nose gear. Are you ready for a lesson in airplane building? Like anything else, there are two ways to do the gear door spring - the right way and the wrong way. Doing it the right way requires measurements, calculations and careful planning. Doing it the wrong way is easy - you just guess where the spring should go and fix it in place. There's a chance that you're guess will be good, in which case you're done. In my case, the guess was bad. The spring touched the tire as the wheel came up (not good when the tire is spinning at 70 mph), and the gear doors closed too early and grabbed the tire. Ouch! I decided that my spring was too low on the doors and too far aft. A heat gun and a chisel made short work of the flox and BID. I drilled out the rivets and repositioned the spring as far forward as it could go and up close to the hinges. Next day I had to make a few dremel "adjustments" here and there to get the doors to close flush, but after an hour or two of fiddling around they worked perfectly. I love the way they snap into place as the wheel comes down.
Now, back to the lesson - which is better? Get it right first time, but take a week to do it, or get it right second time and do it in two days? Obviously this depends on the job in question and the damage done by getting it wrong. My point is that there are many opportunities in Cozy building to "go balistic" with the research, or just dive in and give it your best guess. One of the reasons I've built this bird quickly is because I often use the later approach.
My Sewage System
I'd just finished the doors and was working on the nose wheel cover when the sewage system gave up completely. Regular readers will know that the access for our sewage tank is directly under the airplane. Damn! I had cemented over the access last year after the rocket rooter visit. The "honey wagon" arrived, and I had to dig out the concreate to give Carl access with his 4 inch suction tube. Not an easy or pleasant job while working under the main gear. After Carl left with 1000 gallons, I resealed the hole with cement, this time with an easy access option. Hopefully the plane will be at the airport next time.
Nose Wheel Cover
I bought this from Aerocad. I installed two acrylic windows vertically and added a
glass lip all the way around. I also cut some flat, precured 2 BID to fit the front
of the cover and BID taped this in place. After modifying the instrument panel stiffeners
just a hair, I floxed the cover in place and 2 BID taped it on the inside. A couple
of bricks held it down during cure. After cure I trimmed the lips to give a smooth
transition to the fuse floor.
While I was at it, I glassed in a piece of foam to cover the hole in F22 I'd cut way back
when I'd been planning to install Steve Wright's nose lift. Since I'd got Jack Wilhelmson's
smaller unit which doesnt poke through F22, I didn't need the hole.
Strut Cover
The Hockey Puck
About 18 months ago I went down to the Sports Authority store and bought a couple of rubber
hockey pucks. Per plans I'd cut them in half and shaped the edges. Now (Dec 28, 2000) was the time, finally,
to fit half a hockey puck to the plane. I 5 minute epoxied it in place and
prepared the fuselage skin around it for glass. But what to do about that hole around the NG6 plate. Hmmm. I stuffed blue
foam up the holes, sanded the fuselage bottom an inch around and glassed over the whole thing while
glassing the hockey puck in place. When this cured I sanded the edges and used dry micro to fair the
glass surfaces. I even put micro on the edges of the hockey puck to "include" it in the shape and
help it take paint. Maybe this will crack, but for now it looks good.
Strut Door
I cut the strut door from the
one piece prefab part that comes from Aerocad. Predrawn lines on the part indicated that there should be
a triangle of glass at the top of the strut which is part of the strut door. This
seemed strange to me. Why put a large (maybe 6" wide at the top) triangle of
glass at right angles to the airflow. I trimmed the door so it was rectangular and glassed the triangles to
the fuselage bottom instead. I said earlier that my strut is about flush with the bottom of the fuse floor.
This made the strut door a little proud of the fuse, and the interference with the NG3 at the
pivot point made it stick out even more. I solved this partially by cutting out a square for
the edge of NG3 to poke through. This way the strut door was touching the strut all the
way along. I floxed the door in place and put supports under it to help it cure in place.
Next I duct taped the edges of the door and used a little more dry micro to fair
the fuse floor into the strut door. This had all cured, but I hadn't removed the duct tape and recut the joins.
Bill stopped by to see the new nose lift, so I demonstrated it for him. As the
gear started to move, the micro split nicely along the joins with a firm "cracking noise". Ooops!
I guess that's one way to seperate joins that you microed shut. 3000lbs of
force will do it every time. I had planned to install a small landing light in the nose door, but
theres simply no place to put it without having it sticking out in the wind during cruise.
My GPS factory
Having contributed a propeller last year (ouch!) our Golden Retriever, Bailey recovered and decided to give birth to a Garmin GPS on Jan 2nd. Well - not literally, but close enough. See our dogs personal web page. These cute little fellas were sold into slavery (read "loving homes") to help fund my airplane.
The hole at the front
Once the nose strut and gear doors were installed I inverted the plane one last time for final finishing
(see Chapter 26). The gear doors and strut needed a bit of final finishing, and I couldn't figure out what
to do about the "hole at the front". This is where the strut pivots and rotates into the fuselage when the
gear comes down. There's no way to extend the strut cover here because it gets crushed when the strut
rotates (I tried). After a lot of thinking and pacing, and a few failed experiments, I extended the
strut cover about half way up this area towards the nose - up to the point where it would get crushed.
I did this with a piece of pre cured (and pre primed) glass which I curved as needed with a heat gun
and floxed and screwed into position with two tapped holes in the aluminum plate. Now I had a
2 inch * 4 inch uncovered area between the end of the strut and the back of the hockey puck.
I made a little door for this and riveted a hinge in place parallel with the forward end
of the opening. This cover sits about 1/4 proud of the fuselage because of the 1/4 aluminum plate.
I build a fillet each side with a piece of precured glass and flox. The idea (for now) is that
the little door I've built will be held up by airflow, but will be pushed out of the way by the
strut when it begins to lower. The entire floor of the plane is now sealed when the the gear is up.
I even put silicone around the edges for a perfect "airtight" seal. It looks good. I just hope
it works. [Later note: Using silicone prior to final painting was a bad idea.]
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