spitzy

Been looking at builder web sites. Others have had this question as well. If you install the spool piece at the angle shown on the drawings (126 degrees??) then the hinge pin holes don't line up. One builder chose to install the spool piece per the drawings and found that the actuator arms hit the canard. In hindsight, he said he would have installed the spool piece so the hinge pin holes lined up.

The plans don't seem to provide direction on how to accurately adjust the spool piece before drilling holes into the elevators and installing bolts to attach the elevators to the spool piece. CH11 Pg. 6 says to adjust the spool piece so the control arms are "almost vertical". The best way I could figure to get the correct angle was to use the NC-7 jigs to align the elevator with the CZNC-12A Assembly. Doing it this way would make sure the travel of the elevators is correct and make it easier to install the hinge pin. However, I'm not sure if the angle the control arms make with respect to the bottom of the elevator is more important for balance reasons.

It's the "A notch" description in the plans instead of maybe something like "one of two notches" that makes me wonder... There was a picture in the plans also but it isn't clear enough to tell one way or the other. I can't think of a reason why you wouldn't make two notches other than maybe there would be a small reductionin strength. It looks like it only making one notch could limit travel of the elevator but I'm not sure.

Are you supposed to file notches into the torque tubes on both sides of the NC-2 Insert?

I've cut out the aileron, built the trailing edge spar, cut my hinges, and cut out the three .2" notches on the top of the trailing edge spar where the hinges are go. 1) The four layers of BID at the hinge attache points is not thick enough to allow the top of the hinge to be flush with the surface of the wing. Should I build additional thinckness in the trailing edge wing spar to make the hinges flush with the top surface of the wing skin or leave a bump on the top surface of the wing caused by the hing joints sticking up? 2) The instructions request that you cut out the .2" notches for the same dimension as the hinges. However if you snub over the hinge pins then the notches need to be bigger to accomidate the additional length caused by the hinge pin. Also, if you cut the notch to be the same width as the hinge is long (per the instructions) then I don't see how the hinge pin can come out. Why do we snub the hing pins? Should I cut out extra lenth in the notches for the snubbed hinge pin? Should I cut the pins flush and not snub them? What have others done here? 3) I think I remeber reading somthing about using teflon hinges instead of the aluminum. Any opinions here? Thanks!

Just got back from Ukia. Picked up a bunch of SWEET pre-fabbed parts from featherlight. Anyway I asked Mike and Larry about this question. Went back and forth about it and determined that is shouldn't matter if my conduit comes out of the recessed vertical face inside that wing root or if it is bonded along the inside of the "wing cubby". (sorry I've had a few beers and don't know the real word for that inside area along the upper side of the wing root. From now on I'll call it the wing cubby) Seems to be total paranoia on my part...

Anyone have any ideas about how to modify the Cozy IV to cruise at 300 mph?

Not sure if you are supposed to counter sink those rivets or squish the ever loving heck out of em... Anyway I thrashed around for a while, got something that looked like it would work then bought the plates from Cozy Girls. Theirs are much better than mine. I highly recommend purchasing these parts. Big time savings and it made it easier to line up / install the lift tabs and bolts.

Sputnik :-)

Papa, What is the best way to contact you? I might be interested in speeding up my project. -Mike

I've been looking at some builder web pages for pictures of the root section of the wing. It looks like that rudder conduit exits the shell... Almost the same way I built mine. I'll post what I ultimately choose to do in case others have this little problem.

Looks like the plans conflict here. If you look at view G-G the Rudder Conduit exits the vertical plane of foam INSIDE the shell. However if you read the instructions for step 8, you need to route the rudder conduit down .7" over the last 8" length at the root of the wing. If you follow the Step 8, you find your conduit exits the vertical edge of the actual shell. Because I've moved ahead, I'm not sure what is correct. The picture or the instructions in CH 19 Step 8. I assume the picture is correct but I'm not sure. If the instructions are to match the picture, I think you should start dropping the conduit down to .7" over the last 8" before the vertical plane INSIDE the shell. Also note if you measure the picture, the conduit exits this vertical plane .7" below the top wing surface. Any one know how this wing gets attached so they can verify how to route the rudder conduit?

This is a pretty old thread. Is there now a best solution confirmed?

I understand epoxy is not resistant to alcohol. I also understand fuel is being blended with alcohol. Any bulletproof solutions to alcohol proofing the fuel tanks on the Cozy out there?

CRAP. I layed up the top and bottom spar caps only to find there was a strip of bondo embeded around the corner of the shear web under each spar cap. This happend because I put a bunch of bondo along the boards used to create my dams. I didn't like what I saw at the time but I figured it would be easy enough to scrape out a little "fillet" of bondo. I started with my grinder to get it out and it apears I will have a channel carved out between my spar cap and the shear web almost the entire length of the shear web about an 1/8" deep if I'm to get the bondo out. It's also impossible to crind out the bondo without damaging the underlying spar cap layup. I think I'm going to scrap the part. Bummer after all the hours I've got into it but I just don't feel comfortable with it. Any one have good success creating a dam that is both sturdy, doesn't create bondo between the spar cap and shear web? Maybe the best bet is to use a board that goes all th way to the table and ensure the bondo used is put on there well below the rounded corner. Then the long fibers will fall down into the crack or rounded area and fill it up nice and strong.

I ended up giving up hot wiring my wings. Mostly because I coundn't find a dedicated partner to do it. I purchased my cores from Feather Lite. They did a fantastic job. I also got a chance to visit thier shop up in Ukia. In case you didn't know, they used to work for Burt Rutan. Anyway, their set up uses a very thick wire under a great deal of tension. If I was going to do it again I would purchase my cores from Feather Lite. If I didn't have the cash I would use a thick wire, and build a more agressive tool to tension the wire.

Just finished up the majority of the work for one wing. So far it's been the most rewarding part of the project.

I completed my shear web layup and found there was delamination around the corners in some spots. I started to sand out the bad areas and plan to complete the 4 unidirectional ply layup followed by on ply of bid. This is per the instructions to make a repare that is 100% of the origional strength. Given this is the main load bearing member in the aircraft, I've been having second thoughts about doing this. 1) Will the extra thickness or bump under the spar cap caused by the imperfection in my shear web reduce strength? 2) Should I trust a repare in a part like this? I have a feeling that this wing spar was designed to handle a load that is WAY above any actual load experienced to complensate for any small deviations in strength due to the manufacturing process. Any thoughts? I'm considering finishing this one, measuring the breaking point of the thing to satisfy my own curiosity. Then I'll either buy or build another one for my plane.

i have an epoxy pump (MBT-JR from Aircraft Spruce) with flat bottom tanks and a raised drain. this causes problems whenever I want to drain the tanks. My solution is to fill the bottom of the tanks with Epoxy so it is at least level with the drain.

Is it ok to store resin and hardner in tanks that are coated with hardened epoxy?

Out of curiosity, I plan to install one of each kind... The plans show the COM wiring going through the hole in the foam core. I believe lights go through the same hole. Seems like the coax cable for the antenna would pick up noise from the lights... Anyone have problems running lights and COM wiring in the same hole? I'm thinking about running my coax through a channel similar to the installation of the rudder cable.

According to Bob, torroids weaken signals meant to reach your radio radio. I've used torroids to dampen noisy signals at work and I immagine there would be some energy loss... I've spoken to a couple electrical engineers and they tell me the length and geometry of an antenna makes a huge difference. Although huge can mean different things depending on the application. I'll seach some of the archives and see what has been addressed in the past. At the very least, Bob was nice on the phone, responsive, and willing to answer any of my questions. He also has some pretty interesting papers on the installation of antennas in composite aircraft.

Anyone have any good or bad experience with copper foil antennas suggested in the plans for COM or NAV? I've purchased Bob Archer's antennas which are supposed to be much better. I thought spending and additional $300 might make a cheap radio perform better than an expensive one with crappy antennas?

I have the full size drawings. The #5 Jig is not detailed in them. It is in the origional set that comes with the plans

The center section of the spar simply slides into the two square holes you cut out of the aft section of each side. The Firewall will push directly against the aft side of the spar and the trailing edge of each side. The plans say you may have to shim our cut out foam or wood to make it fit. My cutouts match the spar +/- .05". I suppose this means that as long as I assemble the fuselage correctly I won't have to shim our cut out. If however my sides are assembled slightly catawampus, I'll have to carve out the sides to fit... Still don't understand those templates.... The way they work is that you "hook them around the leading and trailing edge of the spar. Unfortunately if you measure the distance between these "hooks" it is inconsistent with all other means of determining the dimensions of the spar. For example here are my measurements: 5.3" = distance between "hooks" on the bottom spar cap template BL0 5.5" = distance between forward and aft foam faces of my spar at BL0 5.5" = depth of the cutout on each of my fuselage sides 5.5" = front to aft face distance at BL0 per CHP14, pg5 ALSO, if you add the height of the jig used to build the spar at BL0 to the thickness of the foam top (5.12" + .25") = 5.37", the distance between the hooks is still too close even if you have a gap of 0" for micro and layups!! The only explanation I can think of is that the thickness of the foam I am using is slightly thicker than the foam used by Nat in his design by .07" AND the dimensions per CHP14, pg5 represent the finished spar with an additional .2" for exterior layups on the spar. Given the instructions say you may have to carve out some foam or shim to get the spar aligned correctly, I have a feeling it doesn't matter. I sent Nat an e-mail but he didn't respond. Maybe I'll try and give him a call.