YellowBlueBird

Lots of rainy days coming up so it is time to build another airplane. This winters project is the Chaos 60 from Bluejay. First, clean up the shop.

soliex

Nice shop, subscribed.

YellowBlueBird

Second, read the instructions and the ADDENDUM. Bluejay now cuts guide holes for a wing jig. So Looks like I need a wing jig. There are a dozen or so pieces of 3/4 inch birch plywood in the shop. This is solid, heavy, straight stuff. There must be a good way to use this stuff and come up with something that would work. Ideas please.

Jerry

Gray Beard

My Feedback: (-1)

Back side of my bench has a splash guard, it was a kitchen counter top, my building board slides against that and I use it as a straight edge. I have built a lot of the Bridi Kaos planes without a jig. I know others that just use wood dowels through a wood frame that sits flat on there building board for a jig. If you need one they are simple to make. I think tower ever sells one.

YellowBlueBird

Welcome soliex and Gray Beard

It looks like the only thing needed is just a simple frame to clamp the rods in that will keep them parallel and stable until the glue sets.

Gray Beard

My Feedback: (-1)

Yep, it just keeps the ribs centered and level until the glue sets up. I have built jigs for some big planes and bipes but have never used one on a kaos. I still use CA for the wing frame up so it's only holding the rib onto the level and straight line on the counter top for a few seconds. If a rib is a bit off after the spars are set then the LE puts them back into alignment. I should have had a nice store bought jig years ago but just made them when needed. I was getting my Kaos kits directly from Joe and can't recall if the jig holes were cut or not back then.

YellowBlueBird

Using a wing jig brings out its own set of requirements. Getting the ribs lined up with them above the plans required a little thought. There were slight deviations in the rib leading and trailing ends. Not enough to cause concern. Just not meeting the leading and trailing edge without a gap here and there.

Bluejay showed the sheeting being attached over a square trailing edge. That creates a triangle gap that just seemed wrong. Thus the tape to prevent sanding into the rib.

mo lata
Jerry

soliex

I've never used a wing jig, but I want to use one on my next build. It seems to me that the expanse between the support blocks would introduce a sag in the wing, what kind of material is used for rods? Did you build your jig?

Dave

YellowBlueBird

The jig is made from 3/4 inch plywood left over from building the work benches. The rods are 1/4 inch steel rods from HomeDepot. There may be enough weight from the magnets to introduce some sag. It seems that it would be a good idea to slide some plywood under the rods in the center before glueing down the sheeting.

YellowBlueBird

The leading edge sheeting is glued to the leading edge and the trailing edge sheeting is in place along with the landing gear plywood reinforcements.



Tomorrow is a work day so not much will happen in the shop.

Gray Beard

My Feedback: (-1)

During one of my build threads someone once mentioned I had a lot of clamps, I think you may have me beat. Then again, a lot of mine are now residing in the pantry so my wife can close food packages. At least I know where they are, just need to open a lot of boxes to find them when needed. Harbor Freight has some great sales on clamps!!

YellowBlueBird

Good evening Gray Beard,

I have been collecting clamps since I was ten years old. Some of those very old ones are in my shop. The new ones are easer to use just press and apply. The old screw style work better on very delicate balsa since the amount of pressure can be controlled. I took those clamps off this afternoon and sure enough there are dents in the trailing edge. some cardboard with clean cut edges might save the marring.

Northern Tools had a nice package of clamps on special a few weeks ago. Six to a package and just slightly different in size and style from any other that I have. They have a center slide that I have not seen on hand clamps before. They work like the keeper on a calk gun.

Jerry

Gray Beard

My Feedback: (-1)

I have the slide/beam clamps, the 6 inch size. Just knock out the roll pin and you can get more length. I have even gotten dents in the wood using 1/8 balsa under those small black clamps.

YellowBlueBird

.The laser beam across the trailing edge looks about right. Some support was added to the center of the wing with a paint stick and small blocks. This was needed when the lead weights were used to hold down the leading edge sheeting. The weights made the trailing edge rise.

Off to the shop for a couple of hours.

YellowBlueBird

The original had one servo for the ailerons. Would it be safe to use two smaller than standard size servos? Where is the best place to put them? how far from the root rib? Center of the panel or closer to the root rib?

Gray Beard

My Feedback: (-1)

I don't recall anyone ever using the single servo on one. I installed mine about 1/3 out from the inside of the aileron, not the center of the wing. Smaller servos?? there is room for a standard size. I just had a complete gear failure on a micro servo that was only controlling an 8 or 10 inch aileron, nylon gears, so I'm a bit gun shy about smaller servos right now but I have gotten away with them in the past. There are also tapered wing/aileron servos if you think room is a problem. I have a set of these from Futaba, you can look them up at Servo City.

YellowBlueBird

Progress is slow. It does happen. some balsa has been added around the landing gear block to help the sheeting hold on when pummeled by a grass field. Cap strips and sheeting on the bottom of the left wing.

The hiteck 225BB servo is smaller than a standard size futaba and delivers 54 oz of torque according to their spec. It should work well in the Chaos wing.

Gray Beard

My Feedback: (-1)

Back in the day of the Kaos design a big servo for us was 48 inch pounds and the design only called for one. I flew my first one with only the 48 inch pound futaba servos for a lot of years. I don't recall the specs but my first digital servos I used in it were about 57 inch pounds. I have always used two servos in the wings and it always had enough servo power.

Bill Diedrich

Jerry and easy way to remove the dents is to wet the area slightly and then apply heat with
a covering iron, dent will disappear, grain might rise a bit but can be taken care of in the final
sanding before covering.

I'm pretty sure you have done this in the past or have your own method, just thought I'd mention
it.

YellowBlueBird

Thanks Bill,

As a matter of fact that had not occurred to me. I will give it a try.

Thanks
Jerry

YellowBlueBird

The wing came off the building board with about an eighth of an inch of bow from root to tip.
One of the 1/4 inch rods has the same curve to it. I am sure it was straight when the project was started.
Is it even possible to straighten this or just live with it?
Some thoughts- use a larger rod to hold it straight and dampen the sheeting on the bottom while new sheeting is being attached to the top.
Other suggestion please.

Jerry

YellowBlueBird

upon further examination the rods from Home Depot can be reshaped rather easily. McMaster Carr has a number of types. Which would be best? Which alloy would be best for this application? Shaft quality is 27 bucks for a three foot length a bit out of my range. There must be something less expensive that would work.

jerry

Sport_Pilot

I had a warped wing from that kind of jig, the steel rods were not straight and sagged. I am told that I should have bought carbon fiber arrow shaft stock from the local sporting goods store.

YellowBlueBird

Would it be possible to take the bow out of the wing by turning it over and putting enough weight on it to bow it in the opposite direction and then adding shear webbing? Any chance that would hold it?

YellowBlueBird

Thanks sport pilot. I will check that out. Maybe Dick's sporting goods will have them