modifications

[dust]

OK here is my long list of mods that i have or *would have done

 

*heat duct - make square - increases ability to flow air

 

extend ducts to toe area

 

*Change location of map pocket, bolts for elec air brake actuator go threw it in current position, slant it up to avoid this

 

*make bulkheads for seatback wider to continue heat duct square section

 

*floor 1" addition under heat duct and seat back brace has to be widened

 

nose gear bulkheads, made two piece removable cover to stop air

 

replace two canopy hinge with one continious that starts and stops before it protrudes

 

hidden belhorns

 

change profile of landing gear bow for less drag, non lift profile

 

add layer of fine weave 3 oz glass to all fuel tank surfaces and moved bulkheads slighty for more fuel

 

made flanges for top of fuel tanks to allow taping of joints and larger surface area for sealing

 

increase elevator length, no i think i mean width by 1/4 inch

 

wedge under turtle deck to increase height by 1 inch.

 

 

short list

enjoy the build

 

 

dust

[steve]

on that list did u change(would heve)the bulk heads in chapter 4 ?

Book said 25 hours if i do it right the first time....hint,tip ?

[Wayne Hicks]

The "25-hour" spec in the plans is a text carry-over from the original Vari-Eze plans!!! That same text got carried over into the Long EZ plans, which got carried over into Cozy, and now the Cozy IV plans.

 

Since the Cozy bulkheads are about 2.4 times wider (?) than the Vari-Eze bulkheads, if you finish Chapter 4 within 60 or so hours, then you're doing great!

 

Look carefully through the Cozy IV plans and you'll note that starters are not recommended. I dunno 'bout you, but I ain't handpropping my IO-360. I'm going to push 'da button.

 

You'll also notice that the CP logo on the hat of Burt's swashbuckling pirate has been modified with some white-out and an ink pen to now be "CZ".

 

There are many more carryovers. It makes for fun reading to catch them as the epoxy is curing.....

 

...Wayne Hicks

[Wayne Hicks]

Just some 2-cent comments to Dust's mod list:

 

1. Of the three Cozies I've flown in, the standard plans-built heat duct does a wonderful job of keeping the toes warm. Plenty of ariflow that already goes to the shoes. I'm not sure why the heat duct would need to be extended forward any more than that if it's just to keep the little piggies warmer.

 

2. Is the 3-oz cloth in the strakes there to increase strength, or to decrease chances of leaks (pinholes)? If it's for strength, I'd say you don't need it (it just adds weight). If it's to provide strength for external tanks added later, okay. If it's to decrease chances of pinholes, I'd say you're increasing your risk of pinholes. If it is for pinholes, I'd suggest you'd be better off peel-plying or plasticizing all epoxy coats on the interior surfaces of the fuel bays.

 

3. You increased the elevator chord length? I hope I misundertood that. If you increase the inboard-outboard length of the elevator, o-k-a-y..... If you increased the chord length, why would anyone want to muck with that crucial geometry?

 

...Wayne Hicks

[dust]

wayne wrote

 

2. Is the 3-oz cloth in the strakes there to increase strength, or to decrease chances of leaks (pinholes)? If it's for strength, I'd say you don't need it (it just adds weight). If it's to provide strength for external tanks added later, okay. If it's to decrease chances of pinholes, I'd say you're increasing your risk of pinholes. If it is for pinholes, I'd suggest you'd be better off peel-plying or plasticizing all epoxy coats on the interior surfaces of the fuel bays.

 

3. You increased the elevator chord length? I hope I misundertood that. If you increase the inboard-outboard length of the elevator, o-k-a-y..... If you increased the chord length, why would anyone want to muck with that crucial geometry?

 

 

item2 - extra layer is to stop pinholes, both laid up at same time and all peel plied and plasticized, nat also thought this was a good idea, we will see ifin i have any leaks

 

item 3 - this mod was sugested by nat also to increase lift for increased weight of front seat passengers

 

enjoy the build

 

dust

[Wayne Hicks]

O-kayyyyyy. Just gotta love specially-approved changes lurking in the dark somewhere. :-) Just curious on the elevators. What did Nat suggest for balancing them?

[dust]

Same, nose heavy

 

the mod was his suggestion, don't blame you for calling me out on this one, you should have and did

 

enjoy the build

 

dust

[dust]

what i imagined for this thread is for builders and especially flyers to list thier mods Soooooooooo that newbes could see that most don't do much and that changes are not really needed

 

enjoy the build

 

dust

[Wayne Hicks]

Okay, keeping in the spirit of that:

 

1. I'm using the Velocity rudder pedals. They hang down from a special shelf built to support the nose top. They get the pedals up off the floor to provide more foot room, especially side to side.

 

2. With that comes the mod to depress the brake cylinders. I'm using a small metal arm instead of the sliders specified in the plans. The metal arms are adjustable whereas the sliders are not.

 

3. I widened the canopy by two inches and raised it by 1.75 inches.

 

4. I left the nosewheel strut 1.75 inches longer than plans. I did this to get more of a nose-high attitude when the plane is sitting on its gear. This provides for a more positive angle of attack for takeoff. (My canard is still at zero incidence relative to the fuselage and main wings, per plans.)

 

5. I made the canopy latch handle into a doglegged shape so that it latches up against the top longeron instead of from the Instrument Panel. That clears up space over the arm rest forward of the control stick.

 

6. Most other modifications were procedural mods, not structural or physical mods. Like jigging the fuselage upside down in Chapter 6, like carving the nose and canopy in one step in Chapter 18, blah, blah, blah.

 

All are documented extensively on my website.

 

====================

Wayne Hicks

Cozy IV Plans #678

http://www.maddyhome.com/canardpages/pages/waynehicks/index.html

[marbleturtle]

I'm going to widen the fuselage by 4", but no major changes.

[Jim Sower]

<... 3. I widened the canopy by two inches and raised it by 1.75 inches ...>

What exactly did you do to achieve this? I'm planning to bring the camopy straight up from the fuselage sides to the extent that it's practical, but haven't got much farther than the notion. How did you do your expansion?

 

Inquiring minds need to know ....

[Wayne Hicks]

I raised and widened my canopy by lofting new curves for the canopy top (profile) and the sides (planform).

 

I'll discuss here how I raised the height. I'll provide a second post as to how I lofted the sides.

 

Raising the height is simple. You'll need your M-drawings for the J1 through J5 jigs, a marker pen, and a flexible yardstick. I've attached a figure to show what I'm talking about. It's not to scale and is highly exaggerated to point out the process. Do not use for cross-country navigation, okay?

 

Plus my plans are at home and I'm going from memory. (Danger!)

 

1. Using the long side of your workbench to serve as a reference for the top longeron, mark off the FS station locations for each J jig (J1 through J5).

 

2. Take the M-drawings, measure the height of each jig, and transfer the height measurements onto the workbench. Hammer in nails at each height measurement.

 

3. Using a flexible metal yardstick, bend the yardstick around the nails and draw in the side profile curve for the top of the canopy. (I did this to physically see what that profile looked like.)

 

4. At the J1 and J2 stations, measure up however much you want to raise your canopy height. Per the plans, the J1 and J2 stations are supposed to be nearly the same height. It’s okay if J2 is not as high as this helps alleviate the canopy glass-to-turtleback depression. I used 1.75 inches. Why 1.75? There’s nothing magical about that. It was what I felt like doing at the time. One inch wasn’t enough to get rid of the canopy depression. Two inches seemed way too high. I threw a dart on the wall and it stuck a little right of halfway between 1 and 2. Voila. 1.75 inches!!

 

5. Keeping the J5 firewall station the same height, loft another curve to be more or less in curvature to the original curve. I simply eyeballed it.

 

6. Measure the height difference at each J- location between the original side profile and your new side profile. Make note of these measurements and add that height into the length of the legs (vertical side) when you cut out each J jig frame.

 

There is a simpler way to do this by just adding a wedge underneath. But I don’t like that idea. I acutally did that on my first canopy. It's too high at the J1 and J2 locations and I eventually had to cut away the outside glass a bit, recarve most of the think wedge away, and reglass the otuside skins. I liked this process much better. Doesn't take very much added time at all.

 

....Wayne Hicks

[Wayne Hicks]

You can widen the canopy using the same process. I'd caution you up front that there are issues with doing this. So read the last notes on the bottom of this post.

 

1. Starting from one corner of your workbench, once again use the long side of your work bench and mark off the FS station locations for each jig using the short side as the reference plane for the J5 firewall jig.

 

2. Take the M-drawings, measure the width of each jig, and transfer the width measurement onto your work bench. Hammer in nails at each width measurement.

 

3. Using a flexible metal yardstick, bend the yardstick around the nails and draw in the planform curve for the side of the canopy. (Again, I did this to physically see what that planform looked like.)

 

4. At the J1 station and J2 stations, measure out however much you want to widen your canopy. I wanted to widen the canopy by two inches total. Since the M-Drawings specify the measurements for half of each jig, I added one inch to the width of the J1 and J2 stations.

 

(Note: If you want a canopy width that matches exactly flush with the inside of the longerons, then all you need to do is (a) mark off the jig FS locations onto the longerons, measure the left-right distance between the longerons, (b) transfer half that measurement to your workbench, and © loft that exact curve. Personally, I’d take some thick cardboard, lay the cardboard across one of the top longerons with its long edge along the fuselage’s centerline, reach underneath and mark off the EXACT longeron planform. I’d transfer that EXACT profile onto the workbench.)

 

5. Keeping the J5 firewall station the same width, loft another curve to be more or less in curvature to the original planform. Again, I simply eyeballed it. Per the plans, the J1 and J2 stations are supposed to be nearly the same width. I kept the width measurements nearly the same because if you don’t, you really will get a sharp discontinuity where the canopy glass meets the turtleback.

 

6. Measure the width difference at each J- location between the original planform and your new planform. Make note of these measurements and add that width at the top centerline when you cut out each J jig frame. Why at the top? Because it’s the easiest place to add the extra width without relofting the curvatures at the 10 o’clock and 2 o’clock positions.

 

Have you heard the axiom, “change one thing, change two more things?” Well, there are two things you really need to be aware of.

 

First, adding height and width to the canopy changes the circumference of the canopy glass where it meets the turtleback. Going from memory (danger! Check me, please!) the plans-built canopy has a 41-inch circumference. Adding 1.75-inch height and 2-inch width changed my canopy’s circumference to 45 inches. The canopy guys need to know this when they make your canopy so they can blow the canopy a little deeper.

 

Second, widening the canopy decreases the amount of lip area under the canopy frame for mounting the canopy hinges and the canopy latch hardware. I really felt like 2 inches was as wide as I wanted to go. I didn’t have any issues with the canopy hinges. But as it is, my canopy ended up wide enough at the cut line that I had no lip left. I had to add a bracket there to mount the aft canopy latch tab.

 

Have fun drawing marks all over you epoxy-stained workbench. :-)

 

...Wayne Hicks

[Joe Patterson]

I can't say enough about how valuable the information is from you guys that have built already.

 

I really want to make this build happen, and it won't........unless I save every dollar possible.

 

I am on the low economic end of Aviation. Every mistake you guys made, and confessed , gives not only some direction to those who follow, it makes it a lot more possible for someone to follow.

 

Please continue, with your records. I for one, do appreciate the extra work it takes .

 

Thanks again,

To Kind of Quote a GREAT LEADER.....

 

 

enjoy my questions

Joe