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General control line discussion => Open Forum => Topic started by: Crist Rigotti on November 27, 2024, 06:58:41 PM
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Time to start on next year's airplane. This will be a revised version of the 2023 Agenda. The changes from the 2023 version are as follows:
1) Wing Area increased from 628 to 646 sq. in.
2) Nose lengthened 3/4"
3) Less elevator area.
4) Wider fuselage by 1/4"
5) Flaps extended 1 rib bay.
6) Added 1 degree of downthrust and .25 degree of positive stab incidence.
7) Slightly modified the wing sheeting layout.
8) A slightly thicker wing at the tips.
9) Other misc. minor corrections to reflect how it is really built.
10) Clipped the tips of the stabilizer.
Wing Span - 57 3/8"
Wing Area - 646 sq. in.
Stab/Ele Volume - 27.25%
Stab/Ele Ratio - 63/37
Flap % - 14.3%
Weight Target - 53 ounces
BadAss 3515-710Kv
ESC - Jeti Spin 44 or 66
Timer - Igor or Fiorotti
Battery - New Clear 6S 2600mah Li-Ion
Prop - Igor 12 X 5N 3 Blade CF prop
I wont be able to start on this till next week. It uses the Pat Johnston P+ airfoil. I drew the ribs myself and Pat Johnston laser cut them. In the mean time here is a pdf of the drawing and Weight and Balance sheet. I included a drawing of the 2023 version.
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Here we go! This will be a very nice instruction building. Take some notes, I know I will!
:) :)
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Crist, have you considered moving the canopy back to enhance the aerodynamic and aesthetic qualities of the airplane? 😉
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I like the clipped wing and stab, looks good.
MM :)
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Looks great Crist.
Mike
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Crist, have you considered moving the canopy back to enhance the aerodynamic and aesthetic qualities of the airplane? 😉
Mike, I did! Then I sobered up. :)
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I like the clipped wing and stab, looks good.
MM :)
Thanks.
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Looks great Crist.
Mike
Thank you.
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Gonna be fun H^^
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Crist,
I really like the design. Would you mind if I build one, or at least maybe use the wing design? Will the provided PDF print full size if I take it to a Staples or similar print shop? Will Pat cut ribs for your design for others?
I have used Pats ribs for his mustang and they were excellent. Thanks for your consideration.
Tim
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Crist,
I also have a question about what appears to be left thrust and the down thrust. What are you trying to correct with those modifications?
Thanks
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Crist,
I really like the design. Would you mind if I build one, or at least maybe use the wing design? Will the provided PDF print full size if I take it to a Staples or similar print shop? Will Pat cut ribs for your design for others?
I have used Pats ribs for his mustang and they were excellent. Thanks for your consideration.
Tim
Tim,
Sure go ahead and build one. It is a terrific flyer.
Wait a day or so till I can upload a revised drawing. Yes, the pdf will be full size drawing of 36 x 84 inches.
Pat Johnston cut the ribs for me so he has the file and I'm sure he'll cut you a set.
In a few days I'll start the full build log. Been busy with other stuff that needs to be done before I settle into another build log.
Check your PM for other details.
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I just uploaded Rev F of the drawings. This is the plan I'll build to. Starting in a few days!
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Crist:
Have you given any thought to making it inline? The nose would be a problem but if you raised the wing and lowered the stab it wouldn't make the nose too difficult.
Ken
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Crist:
Have you given any thought to making it inline? The nose would be a problem but if you raised the wing and lowered the stab it wouldn't make the nose too difficult.
Ken
Why would he do that? What would change for the better from his current design?
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Why would he do that? What would change for the better from his current design?
He would never know unless he tried. I just wanted to know if he was considering it.
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Crist:
Have you given any thought to making it inline? The nose would be a problem but if you raised the wing and lowered the stab it wouldn't make the nose too difficult.
Ken
Ken,
This design flys terrific. Why mess with the basic layout?
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I always look forward to a detailed Crist Rigotti build log!
Thanks for your efforts to document and share each build.
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OK, time to start posting my build. It's been delayed some because I needed some wood and where I ordered it, he hasn't sent it yet. So I ordered some from another source and that should arrive in a day or two. In the meantime I started on the fuselage. I like to do the stab first, then the wing and finally the fuselage. But not this time. Fuselage first, stab, and then the wing.
First thing I did was print out the formers from the plans and glued them to the balsa using 3M 77 spray glue. Formers F3 and F6 were made using some 7# 3/32 balsa and 2 pieces of 1/64 ply on each side. Glued together using medium CA. Former F13 only has 1 side of 1/64 ply on the aft side.
F1 consists of 2 pieces of 1/32 basswood glued with the grain 90 degrees apart using medium CA. F2 is 1/8 G10 fiberglass. Al the rounded tops of the formers from F3 through F14 are 1/8 6# balsa. Formers F7, F8, and F9 are also 6# 1/8 balsa. I usually used 1/16 balsa for these in the past and kept breaking them, so I went to 1/8 this time. Not worried about the weight because most of the former will be cut away for the wing.
The "window frame" formers used 6# 3/32 balsa glued together with thin CA.
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The fuselage sides are 3/32 balsa. I had to splice some 4" stock to get a piece long enough for the side. The aft portion was 5# and the forward section was 8# wood. This splice was made just forward of the LE. After cutting out the 2 sides, they were taped together and sanded to make them identical. Then the 1/64 ply doubler was epoxied in place using some System 3 slow curing epoxy. This was weighted down all night. I then placed them on the full size plans and marked the location of each former, stab and wing cutout, hatches, etc.
I then glued on the 1/8 square along the bottom, on the top edge of the battery compartment bottom, and underneath the LG mount using thin CA. I then glued on some 1/2 x 1/8 TE stock behind F2 and in front of F3. This was done not only to reinforce those formers, but to also allow a better flow of air though them using medium CA. I then glued on some 1/64 ply doublers for the tail wheel mount using medium CA.
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I made the battery compartment tops and bottom from 1/8 Lite Ply. I made the battery hold down system using 1/8 Lite Ply and some balsa. I use some Apex velcro battery straps and notched the mounting places for the strap. On the top and bottom, these were glued on using medium CA. The 2 parts that were glued to the fuselage sides were epoxied in place using some 15 minute epoxy and weighted down overnight.
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I then cut out the battery hatch along with the adjustable elevator horn hatch.
The elevator horn hatch cutout is lined with 1/32 bass wood. The hatch itself is lined with some 3/32 bass wood. This was done so I could use rounded corners on my hatches. I found over the years that square corners are harder to deal with when applying the finish. I had a tendency to sand through the finish on the corners. So I decided to use rounded corners on all my hatches.
On the cutout, I glued in some small wedges in each corner using thin CA. The grain is typical like adding a gusset. These were then filed down using a rat tail file. The hatch corners were sanded down to match the rounded corners of the cutout. I also made sure that there was some clearance between the hatch and cutout for the finish.
If you look you'll see one corner that was sanded to the wrong profile, and a filler piece was added and then sanded to the proper profile. Remember, all modelers make mistakes. The good ones correct them!
Also look again and you'll see the rudder horn push rod attachment point. This should have been on the right side not the left side! I put one on the right side! Getting old!
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The battery hatch was made in a similar manner as the elevator horn hatch. Before I glued on the 1/64 ply doublers, I cut 2 holes for the magnets into the balsa sides. Once the doublers were glued on, I cut out the hatch, lined the opening, lined the hatch, glued in the corner gussets, rounded them and profiled the corners of the hatch.
I cut the holes in the balsa sides first for the magnets before gluing on the doublers. On the Agenda 2023 I didn't do it this way and when it came to installing the magnets, I had the "drill" a hole for them through the 1/64 ply doubler and into the balsa wood. This was tough and I don't want to repeat that. I now simply turned the hatch to where the 1/64 ply is on the outside and I have a very nice pocket to glued in the magnets. The pics will make this all clear.
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Very clean work. 👍🏼
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Thank you Paul.
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Time to frame up the fuselage.
I use my tried and true fuselage jig. I first tape down the "top" view of the plans. In reality it is the bottom view because I frame up the fuselage upside down along the top of the fuselage sides. I cut small triangle holes every so often along the center line of the plans. Then when I tape the plans to the jig, I can be sure the center line of the plans are along with the center line of the jig. I then cover the plans with wax paper.
I then set each vertical block along the outside lines of the fuselage shape and just snug down the wing nut. I insert the fuselage sides and align the F6, the LE former, to the plans. I insert each former along the marks I drew on each fuselage side. When I'm satisfied that all looks good, I then glue each former in place using thin CA. Once all the formers are glued in, I then glue the tail post making sure it is vertical using a triangle.
I then glued in the Lite Ply battery compartment bottom. My 1/8 Lite Ply has a slight bow in it and that is why I glued in the 1/8 square pieces. When I glued in the bottom, I just pressed down on the Lite Ply to seat it on the 1/8 square pieces. Hence a nice flat easily located battery compartment bottom.
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Once out of the jig, I then sanded the bottom and the top flush using my flat sanding set up. Sure beats just using a sanding block. I set the fuselage on the sandpaper and gently drag the fuselage along the sandpaper. A few swipes and all is flush.
I then epoxied on F2, the firewall seeing its G10. Let it cure overnight.
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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.
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Gorgeous work, Crist! Always enjoy watching your builds!
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Thanks Jason.
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Master Craftsman. Thank you for sharing Crist. Really appreciated.
sina
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Thank you for sharing your beautiful craftmanship with us. I do not possess that skeeeeel!!! : )
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Thank you Sina and Gaylord.
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I'm including some details on how I do my tail wheel mount.
I use 3 pieces of 1/16 birch ply glued together with the narrower 2 pieces glued to from the slot for the .078 music wire. I used medium CA for this. I then drilled for a 4-40 blind nut which will be used for the 4-40 screw and washer to hold down the strut. I then used some 3/8 square maple motor mount stock for the strut support. It was rounded off then epoxied in place using 15 minute epoxy. Then a .078 hole was drilled for the music wire. This assembly was then epoxied in place.
Look closely and you'll see some 1/8 basswood glued onto the sides of the mount. I made the mount, then decided to widen the fuselage 1/4 so I had the widen the mount slightly too.
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I started molding the top blocks. All the blocks are made from 3/32 balsa. The middle and aft most blocks are made from 4 1/2# stock. For the aft block I spliced onto each side of a 4 wide stock, 1 1/2 to make it 7 inches wide. I then measured the mold at 4 intervals to get the width I need for the balsa. I then marked the center on each end to help align it when putting it on the mold. I then soaked the balsa in hot water only for about an hour. I then placed the balsa on the mold, aligning the center marks and I taped it in place at each end using masking tape. This is to assure that the balsa doesn't move too much when I do the wrap.
I then wrap the balsa and mold using 4 wide bed sheet. I don't use ACE bandages because it leaves waffle marks in the balsa. The bed sheet idea came from Al Rabe. Once wrapped tightly, I use another strip of masking tape to keep the bed sheet from unraveling. Using my hands, I then press down all over the mold to be sure the balsa is seated against the mold. I have let this dry at least overnight and have even put it in the oven at 170F for about half an hour.
Once dry, I remove the tape and the wrappings. I then use a #11 Xacto blade glued onto a piece of wood the same thickness as the base on the mold. I then trim the block by running the trimmer along each side while I hold down the mold and balsa firmly. I mark the ends along the mold so I can trim the balsa to length. The balsa then is popped off the mold.
I mark the locations of the formers along each side and along the centerline. I then glue in each former using thin CA on both side of the former. Then quick swipe on my sanding plate to make the bottoms even.
I made the aft top block along with the most forward block. The most forward block is made from 7 1/2 # stock because I want the nose area tougher. I slit the balsa at the very front and took out a slice of about 1/8 at the firewall because of the taper down to the firewall. I'll make the middle block soon from some more 4 1/2# 3/32 stock.
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Crist,
What is the silver material that is the base of your flat sanding station?
Also, what adhesive do you use to bond the sandpaper down to the flat surface?
Great job with the Build Log !
Thanks.
Warren Wagner
Bradenton, FL
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Crist,
What is the silver material that is the base of your flat sanding station?
Also, what adhesive do you use to bond the sandpaper down to the flat surface?
Great job with the Build Log !
Thanks.
Warren Wagner
Bradenton, FL
It's a piece of aluminum honeycomb I got when I worked at the airport.
I use 3M 77 spray glue to glue down the sandpaper.
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Let's build the stabilizer!
First thing I do is build up the TE. It is 2 pieces of 1/4 x 1/2 7# balsa and 1 piece of 1/32 6# balsa to form the hinge slots. I then mark the centerline and hinge slot locations. Once this is done, I cut the 1/32 pieces to size. I then pin down the marked lower half of the TE against my 4 foot level to assure a straight TE. Using medium CA I glue the 1/32 pieces in place. Then I glue on the top 1/4 piece using medium CA. Once dry, I run it through my Dremel table saw to true up the forward and aft sides of the TE. I then used medium CA to glue on a piece of Dave Brown .007 unidirectional carbon fiber strip to the forward face of the TE. It is sanded smooth and it's ready to begin the actual build of the stabilizer.
The frame of the stabilizer is made from 2 pieces 5.2# 1/4 balsa with the usual 1/32 balsa in the center. I used medium CA to glue each piece together. Once glued, the angles were cut and then trued using my Permagrit sanding bar with the piece held up from the table top with an extra 1/4 balsa. These were pinned and glued in place using slightly thinned Titebond glue. The bottom 3/32 6.4# center sheeting is then glued in place using thin CA.
After the glue has dried, the frame is cut to its outer and inner outline, sanded and pinned in place. The center 1/8 5.8# ribs are then added and the top center sheeting is glued in place using Titebond glue along the ribs and thin CA along the LE and TE. I have to used thin CA along the TE because the sheeting and ribs go up against the carbon fiber. Each rib has a 1/8 hole punched into it to allow the heated air to escape when Monokoting. You'll also notice that there is a hole in the bottom sheeting. Air escapes through this hole, through a similar hole in the stab platform and into the fuselage.
The rest of the ribs are glued in place and the stab is now built. I'll later sand smooth, taper it towards the tip, shape the LE and round the TE. Right now it weighs 51 grams. Target weight is 37 grams. I figure with the tapering, shaping, and rounding I'll should make my target.
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Looking good Brother #^
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Thanks Mike.
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Let's sand in the stabilizer taper. It tapers from the outboard edge of the center sheeting to the tip. The tip is about 7/32 high. I have a jig that I made up when I did the 2023 Agenda and I used it again. I draw 2 lines on each tip that I want to sand down to. Before I put it in the jig, I add the elevators using some 1/32 plywood in the hinge slots and then I use masking tape on the bottom to hold the elevator in place. After the stab is secured in the jig, I start off with my plane, and then switch to a 80 grit sandpaper block that fits on the top of some 1/16 x 1/2 aluminum angle that has the taper cut into it. When I get close I use a straight edge to see if the taper is straight. It usually isn't and I have to sand the high areas. Once close, I switch to 120 grit block and then finally a 220 grit block. I do the other half the same way, then flip it over and use 1/8 Lite ply to shim up the tip before I start sanding in the taper. Then do the other side. I then remove it from the jig and sand it some more with the 220 grit block, This time it is all over, not just the taper.
I then glue on the 1/32 bass wood end caps using medium CA. This will protect the tip and gives me a crisp edge for the finish. Then I round the TE and shape the LE to a point using 120 grip and then finally 220 grit. I then drip thin CA on the LE to toughed it up and then go over it again with 220 grit.
My weight budget was 38 grams and this came in at 37 grams. Yeah, 1 gram under budget.
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This should have been posted first, then the stabilizer taper.
I made the elevators from 2 pieces of 1/4 balsa. One was 5.3# and the other was 4.6# and 1 piece of 1/32 6# balsa. After cutting the 1/4 balsa to a rough shape, I edge glue the 1/32 balsa together to form the hinge slots. Note the grain is 90 degrees to the 1/4 balsa tops and bottoms. This is done to act like the elevators are made out of "plywood". I layout the hinge slots and the aluminum elevator horn tube locations. I then notch each 1/4 balsa for the horn tube. I then glue in the horn tube using medium CA. The horn tube is vertically centered and placed 90 degrees to the LE by using a jig that made up.
I use some 3/4 masking tape where the hinges go to prevent the slots getting epoxy in them. I use the same System 3 epoxy that I used to glue on the fuselage 1/64 doublers. After I spread the epoxy on the bottom 1/4 balsa, I remove the masking tape and place the 1/32 balsa in place on the bottom 1/4 balsa, then spread out some epoxy on the top 1/4 balsa, remove the masking tape, and place it together and weigh it down overnight.
I then attach the elevators to the stab for tapering. Once this is done, I mark the TE height. I then plane down the elevator and when close to my mark, I switch to 80 grit block. I then use a straight edge to see if my taper to the TE is straight and sand as needed. Flip it over and do the other side. I then glue on 1/32 bass wood end caps using medium CA. I then sand in the rounded LE using 120 grit followed by 220 grit. When I happy I then sand in the hinge pockets using a tool that I made years ago. I pin down a guide so the hinge pocket has true sides.
My budget is 53 grams for both elevators and they came out to 36 grams. 17 grams under budget. So far I'm 18 grams under budget.
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Let's do the fin and rudder.
The fin is made up using 2 pieces of 1/8 4.9# balsa and 1piece of 1/32 balsa. The rudder is made from 2 pieces of 1/8 6.8# balsa and 1 piece of 1/32 balsa. The rudder is made from heavier balsa because it has more of chance to be bumped on car doors, etc!
The fin and rudder are laminated just like the elevators. Notice the grain direction of each side of the fin and rudder along with the grain direction of the 1/32 balsa. Again, this makes these assemblies like plywood. Once dried overnight, I shaped them, rounded, and tapered where needed. The top of the rudder and the bottom of the fins rudder cutout is lined with basswood glued on using medium CA. Then they were sanded with 220 grit and the rudder had it's hinge pockets sanded in.
The fin came out right on target of 16 grams and the rudder was 1 gram under budget at 3 grams. I am now 19 grams under budget for a 53 ounce airplane.
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I now have started on the wing. It'll be built like the 2023 Agenda. I'll use 2 sets of 5/16 aluminum rods setting on some standoffs which are leveled across the span and checked for level across the tip end of each set to make sure they are parallel.
I marked the rib location on each set of rods from the plans. I then slide on the ribs and checked to be sure the rods are parallel to the TE line and 90 degrees to the center line. I have four rods for the jig and they are joined on the center line. The 6# balsa spars were beveled at the center line and the rib locations were marked on the spars. I installed the bottom left spar first making sure the root end of the spar in on the center line. I pinned it in place after locating each rib on the marked spar. The top left spar was installed the same way, ribs aligned with the marks and the root end on the center line.
The right bottom spar installed the same way and butted up against the left spar. Ditto on the top right spar. Once the ribs were aligned with the marks on the rods and spars, I glued in the ribs using thin CA.
I then made up the TE just like I did the stabilizer TE using 2 pieces of 3/16 5.4# balsa and 1 piece of 1/32 balsa. Once cleaned up the rib locations were marked and the TE edge was pinned in place. I the checked to be sure it wasn't tilted and everything was square, I glued on the TE using thin CA.
Next was the inner LE. This was made from 1/8 5.5# balsa. The outer LE will be made from heavier wood to withstand bumps etc. I measured every other rib height at the LE and transferred those measurements to the balsa wood. After cutting them out, I pinned them in place making sure the center line was aligned with the center line on the LE face of each rib. It was then glued in place using thin CA. Because of the height of the tip rib and location of the 5/16 tubes, the inner LE balsa hits the rods so it isn't glued to R13. R14, the tip rib, will be glued in place once the wing is done and I can remove the rods.
I then glued in 1/8 Lite ply bell crank mount/wing spar doubler in place using thin CA for now. When I turn over the wing, I hit it with some medium CA.
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After the inner LE was dry, I planned it down close to the ribs. I applied masking tape the the ribs forward of the spar. This is to protect their profile while I sand the inner LE to size.
I then sanded down the TE to match the rib profile. Again I used masking tape to protect the ribs. No pictures were taken. Sorry.
I then added the 1/16 5.9# balsa TE using thinned Titebond glue. I then added the 1/16 5.5# LE sheeting again using thinned Titebond glue and plenty of pins. The center sheeting 1/16 6.3# balsa was added and glued in place using Titebond glue.
I then added the 1/16 6.8# balsa capstrips using thinned Titebond glue.
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After trimming the tip TE sheeting to size, I then flipped over the wing to do the bottom.
The first thing I did was to install the bellcrank. I make these up myself from 1/8 Phenolic. I triple up the thickness at the 1/8 music wire post. This keeps the bellcrank from tipping so easily. I then epoxied the post and the bellcrank mount to the lower spars and ribs.
The LE and TE edges were sanded down like on the top the 1/16 sheeting was glued into place.
I then added some 1/4 wide 1/16 balsa vertical supports just in front of the aft jig tubes on the ribs that will be covered by the center sheeting. I also added the TE shear webbing in the same area. I then added the main spar shear web on the bays that will be covered too.
If you look closely, you'll see that I cut out the jig tube supports from the center few ribs and withdrew the tubes a few ribs.
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The center sheeting was then glued down using thinned Titebond glue. The caps trips were then added like on the top.
I then cut down and sanded the inner LE to match the upper and lower LE sheeting. I used my Perm-a-Grit sanding bar to sand the sheeting flush to the face of the inner LE.
I then added the rest of the main spar 1/16 shear webs, As I worked my from the center out, I withdrew the forward jig tube, cut away the jig tube hole from the rib, glued in the shear web, and repeated the process till all the shear webs were glued in using medium CA. I then removed both jig tubes and the wing was freed from the jig.
I then added 1/4 1/16 balsa vertical supports to to aft portion of the ribs after I cut out the jig tube holes. After this was done the rest of the TE 1/16 balsa shear webs were glued in using thin CA.
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Now the the wing was free from the jig, I glued in the tip ribs and the inner LE in place. This was then sanded down in prep for the outer LE. The tip sheeting was added using thinned Titebond glue.
I then sanded down the tip TE sheeting to the proper profile and added some 3/16 x 1/8 balsa strip to the tip TE again using the thinned Titebond glue held i place with masking tape. I soaked these strips in hot water for 15 minutes prior to glueing them on.
I then cut the outer LE from 1/8 6.5# balsa. I drew a line down the center and glued them on using thinned Titebond glue and plenty of masking tape.
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I made my adjustable lead out guide out of 2 pieces of 1/8 Lite-Ply glued to the 1/16 basswood tip plate using medium CA. I drilled the 1/8 holes and sandpapered the slot to size. The LE, TE and tip sheeting was sanded down flush to the tip rib and the 1/16 basswood tip plate were glued on using thinned Titebond glue and masking tape.
When dry, I shaped the LE using my templates to achieve an accurate shaped LE.
I then made up and installed my tip weight box. I used medium CA for this. Here is link that details how I make the box. I used some 1/4 balsa to surround the box for my Monokote.
https://stunthanger.com/smf/gettin-all-amp'ed-up!/legacy-40-electric-a-build-log/msg387124/#msg387124
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The TE was rounded and the wing was then sanded down with 220 girt all over to match the sheeting, TE, LE, etc.
All that's left is to terminate the LO, and do the detail sanding before the Monokote.
The wing weighs 190 grams. 5 grams over budget. I'm now 13 total grams under budget for a 53 ounce airplane.
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Excellent work!!
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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
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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.
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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
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You are a true master builder Crist! Love your designs. Can’t wait to see it at the circles!
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Outstanding! (The canopy location is good where it's at...) LL~
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Thanks Chuck and Dave.
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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.
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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.
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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.
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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
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Thanks Steve.
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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.
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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.
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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.
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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!
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Crist,
Real Monokote or one of the more modern offerings?
John
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Real Monokote.
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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.
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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.
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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!
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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.
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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.
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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.
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Updated the OP to reflect the final build version of the plans. Rev H.
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It is finished. 54.5 ounces with 1 ounce of tip weight. Now waiting for a decent day to fly it!
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Very nicely done Crist. Looks great. Wishing you many good and enjoyable flights.
Blessings;
Larry
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Very nicely done Crist. Looks great. Wishing you many good and enjoyable flights.
Blessings;
Larry
Thank you Larry.
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What a wonderful project. Looks great. Thanks for sharing with us Crist.
sina
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Beautiful build, Crist. Congratulations, hope to see it at Houston or Dallas
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Thanks guys.