#35 Model Airplane Building Clinic >> DJAerotech Chrysalis 2m Electric Sailplane

[Stevephoon]

Originally Posted by FishHawk

I'm back building the wings , which I started before the fuselage. This build is a good Winter project. FishHawk

I agree! Slightly more involved than the SA and MM kits I've built before, but nothing hard.

I'll be starting on my next wing as soon as I complete my repairs to my MM Firestorm. The only thing left to do on that is build an aileron and then some covering and control rods.... So hopefully I'll get started next week.

Steve

[FishHawk]

The plans indicate thatch the 1/2X1/8" basswood doubler ends mid way between ribs G and F I assume that the short doubler goes on first with the longer piece on top of the short doubler. Is this correct?
Second it looks like there is a long piece of sheeting which goes from J toB where the spoiler is located. On the plan the wood grain symbol is shown indicating some type of sheeting. Studying photos of completed models this appears to be an error, as these models don' t have the extended wood sheeting just the spoiler.
Thanks in advance.FishHawk.

[FishHawk]

I missed the step about the planking which is step # 14. N the plans but I still want to know about the short doubler. FishHawk.

[Don Stackhouse]

Originally Posted by FishHawk

The plans indicate that the 1/2X1/8" basswood doubler ends mid way between ribs G and F I assume that the short doubler goes on first with the longer piece on top of the short doubler. Is this correct?

Yes, that's correct, as you can see in the drawing on Step #5 of the instructions.

Second it looks like there is a long piece of sheeting which goes from J to B where the spoiler is located. On the plan the wood grain symbol is shown indicating some type of sheeting. Studying photos of completed models this appears to be an error, as these models don' t have the extended wood sheeting just the spoiler....

Look at the plans again at rib E, and at Step 14 of the instructions. The spoilers only run from rib E to rib J. The spaces between ribs A and E, and between J and K1 get planked on top with 1/16" balsa sheeting between the main spar and the spoiler spar. If you run the spoilers further inboard than rib E, you will get excessive pitch-down when you open the spoilers, due to the spoilers blanking the tail. With the spoilers kept outboard of rib E, there will be some pitch-down when you open the spoilers, giving you visual confirmation they are open, and encouraging you to keep the speed up (spoiler increase the stall speed a little), but it will not be excessive.

[FishHawk]

Thinking ahead has anyone used skid on the Chrysalis? FishHawk

[Don Stackhouse]

The ply plate that goes on the belly in step number 7 of the instructions is a skid.

[FishHawk]

I used the steam from a tea kettle to set the bend on the leading edge as suggested in another thread. This method works!
I am using a painters pallet knife when applying glue in the building process, this knife helps in controlling the spread of the glue. FishHawk.

[Don Stackhouse]

It works, but is not necessary. The leading edge shape was originally designed based on tests of what the wood could handle just bending it dry.

The leading edge will bend into the correct contour just fine with a little patience and the right technique. The inboard leading edge is not an issue, but the tricky art is the tip panel. Glue the dowel to the S and T ribs and the tip plate and tip gusset first, then let it sit for a while to let the glue get up to full strength. Bend it in till it just seats the notch in the R rib and hold it there while the glue sets. DO NOT STOP YET. Pull it on in till it seat in the Q rib and glue it, then the P rib, and so on until it's glued to all the ribs.

The key is to let the glue set up at the beginning, CA needs some time after it sets to get to full strength, and if you try to rush the process, it will pull loose at the tip. Haste makes waste.

[Dimeflyer]

Don
I have found that the steam idea works best on any balsa sheet you are going to make conform to any twist on any formers , it helps keep it from cracking or causing
fractures when the glue drys .
just what I have ben shown to work best by older builders in the past .
So I would not fault the practice buy FishHawk and would tell any new builder to use
it in thier new builds just to help them get good results as soon as they start !!
JMO guy ?
George

[Don Stackhouse]

We are not talking about balsa sheet here. The leading edge is a hardwood dowel. We went to great lengths to make sure that D-tube balsa sheeting would be unnecessary for these airplanes, it's something a lot of beginners have trouble with.

As far as the balsa sheeting at the poly breaks and the center section, the airfoil shapes on the Chrysalis involve relatively mild curvatures that have very little risk of cracking.

[Dimeflyer]

I stand corrected Sir , I have not seen the plans or kits for this plane yet .
I am still working on the G.L. and havent even looked at it,s wing plan yet ,
I always start with the fuselage when I am scratching the parts , I always
seem to have more trouble with that than wings and tailfeathers ?
But my normal wings have been built with formers from LE. to TE. and the sheeting or covering from front to back starting just under the LE for the top covering and
I have been using cracked ribs the last couple of small planes so I am a little out
of the loop on this type of wing !
I will try not to be misleading from now on !!
George
P.S. I hate it when I am not up on new or proper info about proceduers on the planes
we build !!

[Stevephoon]

I've now finished my repairs on all of my other planes, so it's time to start on the new wing for the Chrysalis. Just getting started. I'll post a few shots every so often just to show where I am. If anyone wants some pictures taken at a particular build point, just let me know.

The wing kit came with a new set of wing build instructions and plans. The plan scaling is still slightly off, so I'm reusing the original so I'll have one that is not marked on, have holes in.....

I am in no rush to get this done because I am not planning on flying it until the snow is gone and the weather is at least OK. Also, the original purple covering I used from HobbyPartz is still out of stock. I did find what maybe the same stuff, but at twice the price from a shop in Washington (state.) It looks like a match for the stuff that HobbyKing sells. I'm not sure if it is really the same as what I bought from HobbyPartz...
http://www.skywardhobbies.com/Transp...v-t-purple.htm

Steve

[Dimeflyer]

I that the center section of the wings in that photo guy?
George

[Don Stackhouse]

That's the right inboard wing panel.

Hint: Notice how he's using the shear webs to help position the ribs, but he has the webs pushed down almost all the way into position on the ribs. This can make it more difficult to get the webs back off to continue the rest of the build. You only need to push the webs on about 1/8" or so to get adequate positioning.

[Stevephoon]

Originally Posted by Dimeflyer

I that the center section of the wings in that photo guy?
George

Hi George, Yes like down said, it's the center right wing section in the last picture. Here's one more pict of the entire right wing with a few more of the ribs in place.

Steve

[FishHawk]

Steve, any new tips or notes with the new instructions? If you get a chance can you take a photo of the underside of the wing tip. Thanks FishHawk(Bill)

[Don Stackhouse]

You mean like this?

Note, the tip plate lies directly on top of the lower spar cap, and the cap is carved/sanded to a taper on its underside (what will be the outer surface on the bottom) for a smooth blend from the tip rib to the edge of the tip.

The upper spar cap has a gap between its underside and the top of the tip plate from the tip rib to about halfway to the edge. The best way to do this is to saw-cut the underside of the spar cap most of the way through just at the outboard face of the tip rib, then crack the remainder of the cap so you can put a bend in the cap at that point, then taper the underside of the spar cap where it will lie on top of the tip plate, during dry-fitting BEFORE you glue the spar cap in place. Remember to squirt a liberal amount of glue into the saw cut when gluing the spar cap in place (even if you consider yourself a conservative, use a liberal amount of glue, remember that you do not want to have a deficit of glue in that joint! You can wipe off the excess once it's in place so that you don't have any surplus). After that, you should need only a little carving and sanding on top to finish blending it into the tip.

The other approach is to trip off the upper spar cap at the outboard face of the tip rib, then afterwards bevel and fit a piece of spar stock between the tip rib and the edge of the tip plate.

[FishHawk]

Thank you.

[Neko]

May I ask: What's a "spoiler tube" and "spoiler tube anchor plate" (wing, step 6)?

[Don Stackhouse]

Something I keep forgetting to remove from the instructions.

On the original MkI version, we used a single spoiler servo in the center section, with flex cables out to each spoiler. The anchor plate was to anchor the flex cable casing ("spoiler tube") at the spoiler end of the cable. On the MkII version, we went to two servos, one at each spoiler, but I forgot to remove that note from the instructions.

[Al_M]

Gosh! When I built mine, I never noticed that note.

[vicrider]

me eather. my wife keeps saying i dont pay attention, maybe she's right.

[Dimeflyer]

Gee and I thought I was getting old and missing things ?
George

[FishHawk]

I saw the note but checked the parts list and didn't see the tube listed so I correctly assumed that it wasn't needed. FishHawk

[Stevephoon]

I'll admit that I've built three wing halves past that step and never noticed the spoiler tube mention in the instructions either. I basically build from the pictures and then skim the words for notes and glue selection... Not sure if that's right, but it's what I do.

Steve