n00bs Gonna Build a Carden

[FlyguyXII]

So how much of the engine sticks out of the bottom of the cowel? It looks really good!

[gareth.ky]

It's Done When It's Done. Its so close though I really want to see it finished right now!

My allergies have really been killing me. It's been slowing me down. I'm on my way to see a doctor about it. Hopefully I haven't developed a balsa dust allergy.

I put it together with the tail surfaces wheels last night, but no wings. It looked awesome, finally looks like an airplane. Without the muffler or prop up front but with the servos in the back the balance point is in front of the wing tube! I don't want to jinx anything but that's a promising sign.

[gareth.ky]

	Quote: Originally Posted by FlyguyXII
	So how much of the engine sticks out of the bottom of the cowel? It looks really good!

Only about this much:



There is a little triangular cutout to clear the spark plug and the front of the cylinder. The cowl is huge, everything else fits inside no problem, even the header doesn't come close to the side.

[gareth.ky]

First the bad news. The LHS got a new shipment in from Balsa USA and I got the stuff right as it came out of the box. I needed some 3/8x4x48 planks to re-hinge the ailerons. Well everything was warped. I bought 4 planks that were very light but they will not hold true. I can edge true one side and as soon as I cut it length wise both pieces are curved. Basically the stuff is useless and its the second batch I've bought like that. I'm out about $50 on useless wood.

So I have an order in with National Balsa to get the wood I need. If that fails there is also Specialized Balsa. I have no prior dealings with either company but I'll let you know what I get.

So since the wings wont be ready for another week or so I'm focusing on having the fuse done so I can cover it in the meantime.

The Cowl got set up in Hysol and so did the wheel pants. Hysol is some serious glue. Takes a few hours to set up but it doesn't move around which is great. Hysol 'sets' in 4-8 hours a 77 degrees and cures fully in 3-5 days at the same temperature (source). It was about 75 degrees in my garage last night and by the time I went to bed it was set up but still rubbery, by morning its was rock hard. I used almost an entire tube to do the cowl and pants.

It really isn't necessary to clamp those wheel pants. Just get lots of glue under there plywood to it fills the void. I sanded the bottom edge into a shallow curve so it would sit lower down in the pant. The idea with the clamping it to make a small flat spot on the fiberglass where the pant makes contact with the gear leg. Its really not necessary and I kind of deformed the pants a bit. If I was doing it again I wouldn't clamp it.

Canopy has been cut pretty close to its final shape and the cockpit has been built out. I'm leaving the forward planks out of the cockpit floor so a pilot can be installed later. I'm still looking for a pilot I like in 35%. Also the rudder got re-hinged and not it matches up with the V-Stab to my satisfaction.

Just some work filling work around the V-stab and a few odds and ends and it will be ready for a roll out.

[Fixed Wing]

I've had real good results with National Balsa. You shouldn't be disappointed with what they send you.

[gareth.ky]

	Quote: Originally Posted by Fixed Wing
	I've had real good results with National Balsa. You shouldn't be disappointed with what they send you.

I did some reading on some other forums. Some have had issues and some have been very happy. I have sort of been warned that I should get more than I need in case one piece is especially heavy or not right so I got 4 planks and I only really need 2.

Buy the Band Saw so you don't screw up the really nice straight light wood that Dennis puts in the kit.

I wonder where Carden and Dalton get their balsa?

[Neil4]

I had the same thing happen to me on my 35% Dalton. I screwed up some of the wood that came with the kit so I needed some more. As funny as this may sound I got my wood from tower hobbies. I got 4 planks of 1/2in balsa for $10! I was a little worried since it was tower hobbies brand of wood and that it was only $10 but I was pleasantly surprised. The wood came well packaged, no dings and straight as an arrow. If this next order you placed doesn't work out for some reason, try tower hobbies.

Neil

[gareth.ky]

Tower would have worked and I have always had good service from them. They only do 36" lengths and the ailerons are nearly 48". I could splice two planks together if it came down to that.

[Neil4]

Yeah that is what I did. I got the 36" long ones and just spliced them together. As long as you keep the cutting angle on the band saw the same it is fine.

Looking forward to seeing how the DA 85 pulls you 35% Carden. I maiden my 35% Dalton 260 on wednesday with a DA 100 and it has very good vertical with a 27x10 PT prop on the front.

Neil

[gareth.ky]

Gonna do a few post on some different things I'm doing...

First I had an idea for making it easier to see when the surface is centered up to the bevel material. I drew some parallel lines on the hinge material. One set of lines is just inside the widest part of the surface and the other set is just wider than the narrow end. The lines are measured out from the center line.

Now this is really hard to get on camera but you can see very easily when something isn't centered. The lines wont disappear at the same point on either side of the surface. Its that simple. Very small deviations can be seen easily and corrected. Here is an example from CAD. On the left is a correctly aligned surface. On the right the surface has been rotate 1/2 a degree. The difference is easy to see where the line pass close to the narrow end.

alignment.png

This has got some big advantages for things like rudders and ailerons where you cant see one end of the stock to check if its centered. With these marks you can align any kind of surface the same way.

I was so happy to get this figured out that i cut the stock off the elevator that I had just replaced (I hadn't beveled it yet). I replaced it using this method. It worked great and I'm happy with the way the rudder and elevator turned out now.

[gareth.ky]

One step I haven't seen too much about is installing the stab tube retention bolts. Even if you do Walt's stab root plate mods you still need these bolts to hold everything tight up to the fuse. It's one of those things I put off because I was afraid i would wreck the stab or the tube or both.

You start by preparing some dowels with holes in the middle to fit a blind nut. I used a bit of scrap wood to make a quick jig to get the drilling right. this is a one time use jig, once you move anything, like the clamps or the table it wont align right again. Just use the right size Forstner bit to make a little hole on the scrap and then put the dowel in the hole. Hey presto, the dowel is retained and centered on the chuck.

From there you need to figure out where to drill in the stab for buried treasure. If you cut the surfaces according to the plans the stab tube runs parallel to the hinge line. The instructions say to locate the dowel 4 1/2" from the root. Going from that i measured things up and fired up the drill press. I used my smallest Forstner bit to drill through the skin and down into the stab tube. Mine worked out just fine with everything in the right spot. Use something shiny to check the location of the hole.

With the scary bit out of the way I used the larger Forster bit to cut the hole for the dowel. The dowels are set in with the blind nuts down so they rest against the stab tube. I used Oak dowel and its to sand so I cut them down to size before I glued them in. They get glued in place with epoxy and micro balloons.

You want the stab tube to end up centered. Take some measurements and do the math. Wrap some tape around the tube so that it cant go in any further than its supposed to when its centered. I made up a pointy bolt to help me mark the tube. You just kinda work it in and out repeatedly and it will leave a mark.

Then its off to the drill press again to drill on the mark. I made some crazy arrangement of clamps for this but it worked. You just drill through one wall of the tube, not all the way through.

With that done you put everything together on the airplane and use Mr. Pointy Bolt to mark the other side and then drill that hole. If your lucky then it will all just go together without a fuss. I didn't have any trouble.

[gareth.ky]

Once more thing before I go to sleep. It fits in the car!

The spinner cone will have to come off but the prop can stay on. The rudder doesn't have to bend much. I'd much rather remove 1 bolt from a spinner than take apart the rudder linkages every time I fly.

Not sure what else I can fit in the car with the airplane.