Click on the image below to download a pdf showing all the foam parts and how they fit together for the Cozy Mk IV.
For the wing cores, the fore and aft sections are already separated. The aft core forward edges come pre-rounded and ready for the shear web layup. Wing cores also come with electrical conduits and aileron cutouts already made. Wings and winglets usually come as a set. If you need only one or the other, contact me and I can cut whatever combination you need.
Upper winglets are cut 3.75" long. The extra length is all at the top. This is easily trimmed to the proper length by the builder but it allows more options when for the tips. The plans have you cut them 47” tall and then add a 1” urethane block to the top. I’m not sure what the purpose of the urethane tip is is but I’ve had a number of builders ask me to leave them long so they don’t have to add that piece later. Also, some people want to do different things with the winglet tip so this gives you more options. If you just want to stick to the plans you simply trim 3.75” off the top to make them 47” tall.
Wing Jigs - Available Now
Precision CNC wing jigs are now available for the Cozy Mk IV. These jigs have been precision cut from 3/4" MDF using a CNC router. They are designed to work the same way the plans jigs work but they were developed by taking cross sections of a 3D wing model in CAD. They should fit much better than the plans jigs but still follow the plans jigging method. They are designed to be a tight fit to hold them firmly in place. A very flat building surface is required (not a shop floor as shown below).
All joiner plates are also provided (also CNC cut). These fit into depressions milled into the jig itself to improve the alignment and strength of the joint. Joiners should be glued in place one one side and bolted on the other per the plans. Bolts, washers, and nuts are included to bolt one side of each joiner.
The Roncz canard is the standard canard from the Cozy IV plans. Foam cores for the canard are available for the Cozy Mk IV.
The leading edges come already separated with the corners already radiused for the shear web. The dowel holes come pre-drilled to ensure perfect alignment of the leading edges.
Cozy IV canard cores include the modification described in Cozy newsletter #53, builder's hint #7 and newsletter #60, builder's hint #1. This modification calls for the removal of approx 1/16" from the trailing edge fishtail area to allow the elevator to attain it's 15 deg trailing edge up limit.
I make 2 types of elevator cores for the Cozy Mk IV, hotwire template elevators and contour template elevators. The hotwire template elevators are cut per the hotwire templates on the plans. The plans tell you to compare them to the elevator contour templates after cutting and then sand them to shape taking into account 0.020" of skin thickness. I think the hotwire templates are were probably intentionally made oversized because the small, thin elevators are rather difficult to cut by hand. In fact, the plans tell you to cut them in 2 separate pieces and then micro them together. With the templates a bit oversize they are easier to cut by hand and it allows the builder extra material to be able to sand them to match. The contour template elevators I make are simply cut to match the contour templates to begin with. CNC allows me to make much more precise cuts and to cut material much thinner than would be possible otherwise. Some people still prefer elevators cut slightly oversized so I offer both.
Another thing CNC allows me to do is to cut the elevators full length instead of cutting them as 2 parts apiece as it says to do in the plans. This means you don't have to micro the 2 halves together to make each elevator. When I ship a canard, it comes with elevators cut full length. Actually they are slightly extra long to allow the builder to cut them down to fit exactly. When I sell the elevators apart from the canard, they are too long and skinny to ship full length so I have to cut them in half to make them less likely to be damaged in shipping.
Canard Jigs - Available Now
All jigs, contour templates, and alignment templates for the Cozy IV canard are now available.
This is a 22 piece kit that includes all of the following:
E - Canard Bottom Contour Checking Template
F - Canard Top Contour Checking Template - cut to match the proper incidence per newsletter #80.
G - Elevator Travel Checking Template- cut to match proper incidence per newsletter #80.
H - Top Elevator Contour Checking Template
I - Bottom Elevator Contour Checking Template - modified to match canard cores cut as described in Cozy newsletter #53, builder's hint #7 and newsletter #60, builder's hint #1. This modification calls for the removal of approx 1/16" from the trailing edge fishtail area to allow the elevator to attain it's 15 deg trailing edge up limit.
J - 2x Outboard Mass Balance Mounting Jigs
K - 10x Canard Jigs
L - 4x Elevator Mounting Templates - this was slightly modified in length to match template E and the other canard bottom shape templates and drawings in the plans
M - Canard Tip Shaping Template
These are all precision cut from 1/2" MDF using a CNC router.
These jigs are used for doing the outside skin layup on the upper winglets. The foam scraps included with the winglets are used to do the inside skin layup. The jigs are precision cut using a CNC router from 1/2" MDF.
Main landing gear fairings have been developed for the Cozy Mk IV by Cozy Builder Kevin Walsh. They are designed to align the main gear strut with the airflow during cruise and provide a lower drag airfoil that is only slightly thicker than the landing gear strut itself. These fairings are simply foam pieces that are designed to be attached to the main landing gear after the strengthening layups are complete. They fit over the strut and have a conduit cut in them for the brake lines. After the foam fairings have been affixed, they are covered with a thin layer of fiberglass. They have been reported to work well but Eureka CNC did not do any testing and can only forward installation instructions provided by customers. Click on the links below for more photos of the installation process.