Caroline does an amazing job of packing. It really is like opeing a present...

First step... cut some holes...

Then "cover" the holes...

The small piece in the center is 1/8" light ply and will be the front of the cannister tunnel. It will also be where the throttle and choke servo's are mounted. You will also see 1/4" sq light balsa which the cannister floor will later be glued to.

Mount the SWB engine mount. Build the Box.

Dennis is trying something new. He is painting the ends of the sticks so you know the weight of each.

Did you know he has always weight all his sticks/sheeting? He uses the heavy / garbage wood to start is fire, as he wouldn't put it in is kits.


The 1st truss side...

Yesterday was not as productive as I would have liked, but some progress was made. I Drilled the holes for the gear screws with a drill press. Glued the caps onto the belly pan and turtle deck. (do this before you sheet it as this will hid them.)

Do you need the caps ? I have always just glued the belly and top right on the frame.

Kent

As an experiment I used Gorilla Glue (Polyurethane) to sheet the rudder. I usually use epoxy and the vacuum bag, but I have heard that you do not need to pre join the sheets if you use Polyurethane. If this works it will be a big time saver.

As with bagging any part, cut the sheeting to be only slightly larger then the part, otherwise the bag will crush the wood. Also make the sheeting into a "book" by taping the trailing edge together. so you put a rudder sandwich into the bag.

Make sure the shuck that is marked down is on the bench as Dennis has made sure this shuck is true. The shuck is outside of the bag. Then the breather cloth and release cloth is placed in the bag, and the rudder is placed on top of the cloth. The vacuum is then pulled down. I keep the top shuck and a bit of weight on top to help hold everything in place. This is not needed once the vacuum is pulled down.

As for the need of the caps, I have always wondered why Dennis puts them in, but followed the his steps as I felt everthing would be an 1/8 of an inch off if I left them out. (1/16 top and 1/16 bottom.

Rob, I'm pretty sure I used poly glue to sheet the foam rudder on my Lanier Edge. It works like a champ when you don't pre-glue the sheeting becuase the end result is perfectly smooth. I haven't sheeted wings like that yet but I'm sure the result will be the same.

Ryan,

I have also always wondered the weight and strength difference between the two methods. I tried to set up a little experiment and do one piece with poly and the other with epoxy, however on the test piece which was 1 foot by 1 foot I could not see any weight change from either glue.

It would be cool if someone could do a right wing with one method and a left with the second to see a weight strength difference, but... It wont be me.

Rob

Tonight I installed the hard point for the aileron servos. I also glued the wing tube into the wing.

A view of the installed MTW cannister mount which is from DA.

One of the places I deviate from the Carden instructions is the socket supports on the truss sides. Carden has you attach them as you are building the truss. I install them as I am attaching the truss sides to the motor box. Let me explain...

After the first truss side is attached to the box at F5, F2 and F3, I side the sharpened wing tube phenolic through the motor box and use it to drill the hole through the balsa side. The processes is then repeated for the second side.

The socket supports are glued in using the phenolic as a guide. This ensures the supports, and holes in the fuse are at the correct angle.

The turtle deck is the trickiest part to bag becasue of the shape, but just take your time and make sure you have a good seal on the bag.

The stabs are straight forward after a turtle deck. Put in all of the hard points and the phenolic and then bag. On the stabs I glued the sheeting together first and used epoxy. Using a fish scale (that does not go down below oz.) I weight the sheeting (including overhang, and the foam ready to be bagged and had 5 oz. After bagging with epoxy I still had 5 oz!

Note... the shucks that are marked "down" are not to bottoms of a surface, but rather these are the shucks that have been trued so you know you will get a perfect part after bagging.

Using Epoxy the Stab weight before and after bagging was 5 ounces. So each stab gained less than an ounce of epoxy. I will have to repeat the test at a later date with a more accurate scale.

Albert... I hope you take accurate weights of you wings before and after bagging with poly u. I will do the same with epoxy.

I have always used epoxy and a vacuum bag when sheeting my wings, etc, and felt it was lighter than any other method. Well I am throwing down the gauntlet.

I bagged the wing on the 300 using epoxy. The weight of the wing ready for bagging plus the top and bottom sheeting was 1 lb. 13.3 oz.

After bagging with epoxy my wing weight is 1 lb 14.3 oz.

So that means one ounce was added using epoxy to laminate my wing skins (top and bottom!) on to a 40% extra 300. Can anyone put up their numbers for sheeting a 40% wing using a different method?

By the way... What do you guys think of using laminating epoxy to install the leading and trailing edges of all the surfaces?

Rob

Why not? it's probably the more expensive route, but I think it would hold as good or better, than anything else that's used.

I'd be curious to know the weight difference as well but unless all the wings were measured on the same scale, it would be almost impossible to get a real result. These small digital scales can be inaccurate. The digital fish scales are even worse (I have one).

One thing I did notice between doing my Edge wings with epoxy and the Yak with poly, is that the poly is, in my opinion, stronger. I always try to rip the sheeting off of the scrap pieces that were cut off for the leading/trailing edges and the poly glue always took more effort as well as left a lot more foam stuck to the balsa. That being said, how much strength is really needed? If the foam fails before the glue joint, in theory the glue joint was stronger than needed to be.

............Mark

mark, i dont know if the scale matters. its not really x weight but the gain that matters, if using the same scale the gain should be accurate

Mark,
This was actually a postal approved scale, and it is always accurate against the post office scale...besides, if the real weight is off a bit, it still would be very close to once ounce gained. (ie if it were really 14.4 to 15.5 instead of 13.3...)

As for the epoxy not being as strong, when you try to pull the sheeting off of a scrap piece, the foam always stays attached to the balsa...so the foam is the weakest link..

ZZ, It is more expensive until you take two things into account...

1) If you do not use the epoxy this year it is toast anyway...

2) When doing a small part, one "pump" is too much so you will have to throw away glue anyway.

Rob

Yeah, good point. It's the net gain that we're looking for. I never bothered to weigh mine before/after so I can't be of help. Like I said, the strength is never really a problem. I've never heard of a set of epoxy or probond wings coming apart from the sheeting letting up. If it ever happened I'd imagine it was more of an application issue than glue joint strength.

Just curious, how many fluid ounces of epoxy is in one ounce? Seems like it wouldn't be a lot.

To create sheeting that is 54.5" long you need to join a 6.5" piece to a 48" sheet. I do this by holding the 48" sheet against a straight edge which is weighted down, and then edge glue the 6.5" piece. the I lightly sand from the small piece to the long piece (so I am pushing the joint closed). I also cut some pieces to be slightly longer than 6.5" so all of the joints are not at the same place. Does anyone have any other methods for doing this?

The other photo is the second wing in the bag.

Rob,

Bagging looks like the way to go for sheeting foam, it looks perfect just sitting there. Is the trick having everything ready to go, so once the glue is spread out, get everything in the bag, lined up, close it off and pull vacuum?

Ward

What I did to get the 54" pieces is lay the 48" piece right at the edge of the table. Then overlap the extention piece over the 48" piece by about 3-4". I then place a square over the top of the two and hold the two overlapped pieces tight against the square. (the bottom thick piece of the square overhangs the table as it is thicker than the two sheets). I then cut down through BOTH pieces with a razor saw at the same time while using the square as a guide. This way the cuts will match up perfectly. Even if saw runs off the guide (edge of the square) it doesn't matter as the inperfection will match the other exactly. If the description doesn't make sense, I can take a picture if needed.

On my next plane I think I might do as above, only cut the two pieces simultaneously at about t 30-35 degree angle. I think will make sanding a bit easier.

I don't edge glue the wings or stabs (just taped well) as the poly glue works it's way up during bagging. I do tape the turtle deck and belly pan as it's easier to wrap the sheeting around the harder radius without the tape.

..........Mark