Flaps.

Yesterday I built the inboard flap.

I use built up flaps 5/16" thick with no taper.

1. Layout the parts.  I use 1/16" balsa to cut the sheeting.  I strip out 1/16" as well the width of the hinge I will be using, and strip some 1/8" as well.
2. Laying out the flap frame.  I build with CA so it is important to keep everything flat on the surface at all times or it will warp as I apply CA during the build. That is why you see the glue bottles laying along the edge.  I have also used thick CA and tack glued it to the bench as well in several areas around the edge. That option actually works the best.  I keep it up against a straight edge as I work as well. I lay down the 1/8 frame around the outer edge of the sheeting.  I lay down the 1/16"wider piece along the LE.
3. Mark where the hinge slots will be.
4. Then I use 1/32" balsa and add another layer along the leading edge leaving blank areas for the hinges.  After I have all of the pieces in place I then use a block sander to thin the 1/32" balsa to the thickness of the hinge.
5. I build in the lucky box.  I use 1/64 plywood lined with 1/8 balsa for the thickness of the flap horn wire.  I leave it a little wide so I can slide it some side to side when I do the final installation.  I glue the horn wire into the box at final installation so it is held in place.
6. Lucky box completed.

That's very nice!!
Doug, do you round the TE edges or leave them square?
really looking forward to seeing this ship ready!!
Thanks for sharing.

Marcus

Doug
I like the idea of make your own adjustable lead out guide as you did.  My son has one on a carrier plane, but its exposed.  The one you built looks really nice, but what do you use as an insert?  I guess I'm assuming you have an insert that you pull out of the lead out hole and move to a new hole.
Duke

Duke,

I will get a pic for you tonight showing what I use.

Marcus,

If I had them squared off I know I would get dents in the sharp edges so I just round them off.  I wonder how much a difference it really is?

I know I can tell tapered vs non tapered.  Non tapered is more effective.

LiPo batteries and charger finally came in.  Now its on a full brushless system from Castle Creations.  The ESC is cool it has a tiny cooling fan on top.  You can hear it running with the car is sitting still. 

This things hauls ass!  Now I can really break something! 

Not that it matters, but doesn't this actually add up to a 1/4" thick flap and not 5/16"?

Yeah its 1/4 plus the 1/32 insert for the hinge slots.  Its not quite a full 5/16 but just a tad more than 1/4.  But it is consistent all the way through. on both flaps.

Here is the wing complete minus the flap horn.  Span is 63".  What you see here weighs 11 oz.  Not super light but should be in the ballpark.

LiPo batteries and charger finally came in.  Now its on a full brushless system from Castle Creations.  The ESC is cool it has a tiny cooling fan on top.  You can hear it running with the car is sitting still. 

This things hauls ass!  Now I can really break something! 

You suck. That thing is going to kick ass in the Lee's parking lot races.

Derek

You suck. That thing is going to kick ass in the Lee's parking lot races.

Derek

I already broke part of the front suspension.  It's fixed up though.  It's almost uncontrollable.   

Back in the shop over the past few days and I built the stab.  For some reason I really enjoy building the stab.  I know once you have read this you will think there is are alot of easier ways to get the same result.  But, for me, I like to build this structure even though I am sure it is over built.  I have an old one that has a large crack in it that can't be used.  I keep it around as a template, you can see it in the first few pics.  I sure makes it nice when there is no plan available to have a part to work from.

I use a flat stab just over 1/2" thick.  Rounded LE and TE.  The span is 29", 4 1/2" root and 2 1/2" tip chord.  As with the main wing the stab LE shape must be consistent.  I mold the LE out of 1/16" balsa. I use a brass tube attached to a piece of wood.  Then wet and wrap as normal. Once the mold has dried I sand a trim the piece from the mold buck.  When removing the piece it can tend to curve up a bit.  Then I attach it to a piece of 3/32" or 1/8" balsa as a backing piece to keep it straight.  I attach the backing piece to the table while attaching the mold to it making sure it stays in place until the CA has fully cured.  This will insure it stays straight.

Next I build the trailing edge.  I like to build in the hinge slots as I build the TE.  I start by attaching the straight edge to the table.  Then I attach a piece of 1/4" balsa to the table against the straight edge.  Then I glue on pieces 1/32" balsa leaving gaps for the hinges.  Next pass over the 1/32" balsa with a sanding block to make sure they are same thickness as the hinges.  Then glue down another piece of 1/4" balsa.  The TE is complete.  

Next I layout the LE pieces and complete the frame.  From there I trace and cut the center section sheeting for the top and bottom.  Next I have to install the ribs in the sheeted area.  From there I install what will be cap strips along the top prior to the ribs.  I put them in first so I can get them nice flat against the upper edge.  Then I flip it over for the rib install and the last of the cap strips.  Trim the edges and clean up any rough edges.  Next, round the TE.  

It's all finished up.  The weight is good.

Just for grins I went back and counted the number of pieces used to make this thing, 96.  Yes, it's true, I am near the edge of insanity.  

The stab went together pretty much as planned.  The elevators are a different story.  I worked for several hours on Sunday and 3 attempts yielded WAY less than desirable results and alot of wasted time and balsa.  I day or two off is in order to come back with a clear mind and get them built correctly.  

      

The finished product.

Beautiful work Doug.  What type of glue are you using for the stab and the wing? 
Steve Thornton

A little more progress.

I finished up the elevators.  I build the leading edge like the trailing edge of the stab matching the hinge slots.

The trailing edge of the elevators is laminated 1/8" balsa, 1/32" carbon blade spar, 1/8" balsa.  This makes it very stiff and still it very light weight.

 

Great job!

Do you cover or sheet the stab/elev??

Marcus

Doug....Go to the Team Trials this year....You will do well in Poland!  The US team needs you!

PLEASE consider this....PLEASE.

Doug....Go to the Team Trials this year....You will do well in Poland!  The US team needs you!

PLEASE consider this....PLEASE.

We have discussed this a time or two. I plan on flying at the TT this year instead of running it.

Derek

Doug and Derek:

You could hardly find a better endorsement than one from PW.

Go for it!

Built the crutch.

Start with 1/2x3/8 maple beams.
Relieve 1/4" in the tank section of the crutch.
Cut out F1 and F2 from 1/8 hard plywood.  I would use 1/16 for F2 on a 65 plane but this is a 75 so I decided to stay with the 1/8 for both.
Using 1/16 balsa trace and cut out three pieces that fit the gap between the beams after initial installation. Laminate with medium CA
Install with epoxy between the beams making sure they are even with the top of the beams.
Cut from 1/8 balsa a filler that spans the area between the to of F1 and F2
Epoxy in place and clamp until dry.
Trim and sand the top piece until it is flush with the top of F1 and F2 and on the sides of the beams.
With the top filler piece in place it ties the beams together across the filler pieces.  It also creates a nice platform for the crutch to stand on upside down when installing the fuse sides to the crutch.

I thought you were going to sit out for one more year.  That's good to hear.
Have you built a new take apart plane yet?

And Doug, you should really consider the TT's.

No I spent all my extra time building a non take-apart plane to save weight. I am happy with the new one it is MUCH lighter than the Matrix. If I were to make the team I would probably build another one but i still have the Dreadnought that flies really well.

Derek

A naive question...
The 1/4 relieved from the mounts is for adjusting the tank, isn't it??

Marcus

Yes, the plastic 8oz tank will need some room to move up to get the right setting.

Built the fuse.

1/8 48x4 balsa for the sides
Cut out needed slots for cowl, wing, and stab per numbers on the sheet
added 1/32 plywood doublers that extend past the wing
Glue the sides to the crutch

Continued

Is the Chevy truck on your workbench for hauling around the particularly
heavy pieces of balsa?

Later

The dremel must have been smokin' grinding all that wood away on the motor mounts!

Whats the deciding factor in the width of your crutch, the width of that 8 oz tank or the width of the 75?

I have done it with the dremel before and it is a beating of the highest order. But now I just use the band saw and it makes quick work of that task.

On this model the width is driven by the tank. I have made them wider in the past and its nice to be able to slant the tank outward for a cleaner shut off.  But on this one I just copied the same as the nats plane. The 75 fits in there nice and snug.

Hello,

I may have been away from here but I have been living in the shop.

I have made some progress.

I like to cover the wing and stab prior to installation into the fuse.  I also cover the flaps and elevators at this time. 
I use poly span.  The surfaces are all covered with 3 coats of 50/50 sig nitrate.  Sanding the last one only.
Next I use about 90% thinner 10% dope mix to apply the ploy span.  I apply the thinner mix to the edges of the surface only leaving the middle area dry.
While one wing panel is drying I do the same thing to the adjacent panel.  Once I am sure it is dry I bring out the heat gun and shrink out the poly span.  You be surprised how much it will shrink and how it will pull out some pretty big wrinkles with ease.  BUT if I shrink it before that thinner edge area is really dry the covering will slip inward and wrinkle and will not be able to be straightened back out.  This happened to me on the outboard wing top side of course.  I went forward and applied thinner mic over the whole panel thinking I could work it back out and get it straight.  The slip was too much and it just wouldnt correct itself.  No worries though.  At this point since it has been attached with mostly thinner I just wet it again with thinner mix and it easily lifts off the panel.  I let it dry out over night and redo that panel the next day with no issues.  I cover the flaps elevators and stab in the same method.  My thought here is that if all the flying surfaces are prepped with the same covering it is that much easier to get a good consistent base for finishing.  It has been working out so far.
Once they are shrunk and covered once completely with thinner mix I let them dry for about 2 days.  Then I start with mix of 60% dope 40% thinner.  I go for 3 coats.  I only sand after the last one and I work the edges first.  If I have enough dope in the poly span the excess with flake off just like SS does.  From there with a used piece of 320 I lightly sand out all the surfaces and the wing.  I am careful not to grind on it.  I am simply knocking down the dope fuzz.  Poly span is not SS or CFV, it is not designed as a filling covering you can sand down flat. When you cut it with sand paper you weaken it and cause the polyester to fuzz up.  The fuzzies can be a nightmare.  But a drop or two of thin CA or a couple more coats of dope and you can lightly sand them away.  Dope will build up on top of the poly span as you go. After 3 coats of the above mix the lightly sanded surfaces are already feeling very uniform and will fill very easily with dope and zinc and final blocking coat of primer. 

Next I built a balsa rack to store my wood.  I have been meaning to do this for some time, 6 years! 

I also took a queue from Derek's finishing thread and built some much needed jigs for my flying surfaces.  I used 1x2 and ripped it on my table saw then ran a bolt through them with a wing nut.  Now I can keep flaps and elevators on there and they will stay straight while applying dope and paint.  Thanks Derek and Eric V for the tips.

Now I am getting ready to install the wing.  First thing I do is add alot of support braces in the bottom area that will be cut out and in the areas around them that wont be cut.  Its like chopping a car, you need something to keep things straight when you go to cut out a mian part of the structure.  Next I cut out the bottom on my band saw and start the initial fits.