2025 Agenda - A Build Log

[Doug Moon]

Excellent work!!

[jerry v]

I then sanded flush the chin up-slope and the fuselage sides flush with the firewall.  I then glued on a piece of 3/8 6# balsa.  When dry, I sanded it flush with the firewall.

I then mounted the motor to locate the nose ring.  I placed the shaft into the 5mm hole in the nose ring and glued it into place using thinned Titebond glue.  Some thin CA along the top to glue it to the G10 firewall.

When dry, I removed the motor and cut away the nose ring to match the round hole in the 1/2 balsa using my Dremel sanding drum.

I than added the 1/16 balsa ESC cooling tunnel located on the bottom of the battery compartment bottom.

To increase content engagement I would like to ask a rhetorical question: which way is more suitable to make a front motor mount? The mount on the left of the photo will allow the motor wires to be located at a 45 degree angle into the fuselage corner where they may possibly get kinked in the narrow fuselage. On the right is motor mount made to allow the motor wires to pass straight down to the air scoop , be free from kinking but interfere with cooling airflow .

Jerry

[Crist Rigotti]

On to the flaps.  These were made from 2 pieces of 3/16 5.5# balsa and 1 piece of 1/32 11# balsa.  Laminated just like the elevators.  After curing, they were tapered toward the tip and the TE.  The LE was rounded and the hinge pockets were added.  I used 1/32 and 1/16 basswood to line the ends as needed to get the correct length.  These were glued on using medium CA.

Both flaps came out at 46 grams.  4 grams under budget.  I'm 18 grams under budget so far.  I have to finish shaping the nose of the fuselage and make up the bottom sheeting.  The canopy will be balsa this time instead of PETG.

[Crist Rigotti]

The build phase is completed.  Here are all the components and a list of their weights.  Not including the canopy I'm 35 grams under budget for a 53 ounce airplane.  The 2023 agenda used a PETG canopy which weighed 15 grams but I'm going to use a balsa canopy and save about another 6 grams.  All numbers shown in grams.  First number is actual weight, 2nd number was the target, third number is the difference.

Wing - 189, 185, +4
Fuselage - 163, 183, -20
Flaps - 46, 50, -4
Stabilizer - 37, 38, -1
Elevators - 36 - 53 - -17
Fin - 16, 16, 0
Rudder - 3, 4, -1
Top Blocks - 28, 27, +1
Bottom sheeting - 13, 10, +3

[Clee13]

You are a true master builder Crist!  Love your designs. Can’t wait to see it at the circles!

[Dave Rigotti]

Outstanding!  (The canopy location is good where it's at...) 

[Crist Rigotti]

Thanks Chuck and Dave.

[Crist Rigotti]

Here is a picture of my weight and balance sheet.  Monokote weighs about 1 gram for every 8.5 square inches of wing area, or stab area, or flap area, etc. I get my build weight from the W&B sheet.  For example the wing finished should be 280 grams.  I take 280 minus 67 for the Monokote, minus 14 for the flap control horn, minus 12 for the flap pushrod and screws, minus 2 for the hinges.  This gave me my target of 185 grams.  The wing came out to 189 grams, hence 4 grams over budget.

[Crist Rigotti]

After looking at my data I realized that I didn't take off the top blocks and bottom sheeting weights from my fuselage target.  My fuselage target was 163 grams and it is 183 grams.  20 grams over budget.  This leaves me at 5 grams OVER budget for the build so far for a 53 ounce airplane.  In reality I'm guessing 54 to 55 ounces circle ready.

[Crist Rigotti]

After traveling for about a week i got back into the shop to make the balsa canopy.  It's made form 5.5# balsa.  I decided on the split canopy method.  After tack gluing the blocks together with 2 small drops of medium CA I cut out a rough outline both side and top views.  I then rounded out the bottom to fit my top block.  I then sanded the outside shape of the canopy.  Once this was done, I split the balsa blocks and hollowed out the center leaving plenty of meat.The halves were glued back together using thin CA.  Some final sanding using the top block and some 80 grit sandpaper and it is now ready to glue on and then the final shape will be sanded in.  The canopy weighs 11 grams.  4 grams under budget.

This pretty much concludes the build phase.

[Steve Berry]

Very nice. A little final shaping and some Superfil, and you would never know it's not part of the original frame work. This is getting real good.

Steve

[Crist Rigotti]

Thanks Steve.

[Crist Rigotti]

I almost forgot to cutout for the flap pushrod.  After cutting the hole somewhat, I need to install the flap pushrod.  I use a piece of 3/16 aluminum tube and insert it into the hole and over the barrel of the bellcrank ball link.  I then insert the pushrod and it automatically aligns it with the barrel and it screws right in.  Remove the aluminum tube and tape in place the flap horn.  Continue cutting away balsa to provide the clearance needed for the pushrod.  Once done I removed the pushrod till after the wing is glued in place.

[Crist Rigotti]

I then covered the wing, stabilizer, flaps, and elevators with white Monokote as is my usual practice.

Time to hinge the control surfaces.  I use Klett hinges.

1) Install the hinge half into the control surface and use a 1/32 wire for the "hinge pin".  The should just touch the LE.  I then remove them and squirt some formula 560 glue into the slot.  A little goes a long way.  I then re-insert the hinges and wire into the control surface with the wire just touching the LE.
2) When dry I install the other half of the hinge on the wire, squirt some glue into the TE hinge slots, and insert the surface with the control horn.  I then use tape on both sides to pull together both the control surface and the wing or stab to minimize the hinge gap.
3) When installing the control surfaces for the final time, I'll use some .025 wire for the hinge pin.

[Crist Rigotti]

I hinged the control surfaces using .025 wire.  I bend one end at 90 degrees about 1/8 long.  I then cut it to length and the, suing my sanding disc, I sand in a taper on the end to aid going through the hinge barrels.  I then drill a 1/16 hole just below the hinge line near the tip on the stabilizer and between hinges 2 and 3 on the wing.  For the wing I drill 2 holes because the wire has to go from the center of the flap toward each end because the flap doesn't go all the way to the tip.

I then insert a small white eyelet and glue it into place using a toothpick and medium CA.  To install the control surface I place it onto the TE and insert the .025 wire through the barrels of the hinges and finally insert the 90 degree end into the eyelet.

[Crist Rigotti]

I put on the trim using the Windex method.  After "drying" overnight, I go over the trim with my sealing iron set at the midway point.

My letters and AMA numbers will be put on later.

On to installing the wing!

[John Paris]

Crist,
Real Monokote or one of the more modern offerings?
John

[Crist Rigotti]

Real Monokote.

[Crist Rigotti]

Time to glue in the wing.

I inserted the wing, then installed both flaps.  I then placed a 1/8 balsa piece between each flap and the fuselage side.  This centers the wing.  I then attached my fabric tape measure to the tail post with a pin.  I then measured to the outboard flap notch at the TE of the wing.  I made this measurement equal.  This squared up the wing to the fuselage.  I then pinned the wing in place and marked where the fuselage sides are both top and bottom.  I removed the flaps and then notched the Monokote from each mark going inboard.  I then sealed the Monokote down real well with my sealing iron turned up to full heat.

I reinserted the wing, installed the flaps, 1/8 balsa spacers and got the wing squared up again then pinned it in place.  I then made sure both wing tips were equal distance from the work bench top.  Once I was satisfied I then glued the wing to the fuselage using medium CA where there was wood to wood showing both top and bottom.

I then fiberglassed the wing center section using 2 oz cloth and my System 3 epoxy.  The FG cloth goes up on each fuselage side about 1/2 inch.  Once the epoxy was applied, I used a square of toilet paper folded several times to blot up the excess epoxy.  If it was shiny, then it is puddled and needs blotted.

[Crist Rigotti]

I then epoxied in the landing gear mount using 15 minute epoxy.

I installed the 1/8 Lite-Ply timer mount using medium CA.

Then pushrods were installed along with the elevator horn. Sorry no detailed pictures.

[Crist Rigotti]

I then glued on the bottom sheeting and top blocks using thinned Titebond glue.  I used a lot of masking tape to hold the sheeting and blocks tight against the fuselage.  When dry, I added the small balsa block on the upper most aft section of the fuselage.

Once dry I sanded the fuselage bottom sheeting and top blocks fair to the fuselage sides.

Staring to look like an airplane!

[Crist Rigotti]

I applied the 2/10 carbon fiber using nitrate dope.  I first brushed on 3 coats of 67/33 dope/thinner sanding between each coat with 220 grit.
I then put on the carbon fiber using 33/67 dope/thinner.  I sanded the edges to trim the carbon fiber.  Then applied 2 more coats of 67/33 dope/thinner sanding each coat with 200 grit.

I then glued in the stabilizer using medium CA.  Then the fin was installed.  I marked the cutout with just a hint of the LE left of centerline.  This was done to be sure I don't have the fin the wrong way.  The bottom of the fin was glued in with epoxy, while where the fin and fuselage top meet was glued in with thin CA. 

The fillets were then applied.  This time I used Super-Fil rather than Aeropoxy Lite.  The Aeropoxy after 13 years was turning bad.

After the fillets had cured, I brushed on some Nitrate dope on the fillets.

Then crossed brushed on 2 Zinc Stearate filler coats.  Tomorrow I'll sand it smooth.

Total weight of the finish is:

Carbon fiber applied and 2 coats of Nitrate - 16 grams
Fillets - 4 grams
Filler coats before sanding - 7 grams  Total 27 grams.

[Crist Rigotti]

Just an update.
After sanding the filler coats, I then cross brushed 4 thin coats of Lite-Coat clear.  I then wet sanded it with 600 grit.  Then I sprayed on a coat of Harbor Freight sandable primer.  Once that was dry I wet sanded it mostly all off with 600 grit.

I then wiped off the model with rubbing alcohol and sprayed on my gray blocking coat.  Once this is dry, I'll apply the glazing putty to fill the small dings and dents.

[Crist Rigotti]

I applied the glazing putty and sanded it smooth with 600 grit sandpaper.  Once all the glazing was done, I shot on 1 more coat of gray.  The next day I sanded it smooth and shot the white.  2 coats over all the fuselage and then 3 more on the areas that will remain white.  The next day I again sanded it using 1000 grit sandpaper.  I then shot 3 coats of clear over the white portions to seal it.

Again the next day it was sanded smooth using 1000 grit, then masked off and the Fokker Red was sprayed on.

The gray blocking coats weighed 19 grams.
The white added 18 grams
The clear seal coats added 4 grams
The Fokker Red added 6 grams
Total weight added so far is 76 grams.

[Crist Rigotti]

Updated the OP to reflect the final build version of the plans.  Rev H.

[Crist Rigotti]

It is finished.  54.5 ounces with 1 ounce of tip weight.   Now waiting for a decent day to fly it!

[Larry Fruits]

Very nicely done Crist. Looks great. Wishing you many good and enjoyable flights.

 Blessings;
   Larry

[Crist Rigotti]

Very nicely done Crist. Looks great. Wishing you many good and enjoyable flights.

 Blessings;
   Larry

Thank you Larry.

[Sina Goudarzi]

What a wonderful project. Looks great. Thanks for sharing with us Crist.
sina

[Gaylord D Elling]

Beautiful build, Crist. Congratulations, hope to see it at Houston or Dallas

[Crist Rigotti]

Thanks guys.