I've built several Waterbombers over the years, and it's time for another one. This one will be a semi-scale model, all balsa (maybe some plywood), with a wingspan of about 48", and will be a simple 4-channel operation.
The first step was to produce a 3-view drawing, exactly ¼ the size of the model. This way, I measure the drawing, multiply by four, and cut balsa as needed. Basically, I'm making it up as I go along.
Fuselage sides and some formers fabricated.
Nice project.
Stabilizer and elevator under construction: parts fabricated.
Stabilizer/elevator assembled and glued, sheeted, shaped and sanded.
Next, I prepared a drawing of the fin/rudder.
@Michael is the stab and elevator covered in 1/32 or 1/16 balsa?
Just curious.
Looks great.
Guy
I saw the first post dated Jan 23 and that it was Michael, and fully expected to scroll down and see a completed airplane. Michael, you're slowing down in your old age.
He's also getting smaller, I think! ;D
Quote from: GuyOReilly on January 25, 2022, 10:22:04 AM
@Michael is the stab and elevator covered in 1/32 or 1/16 balsa?
Just curious.
Looks great.
Guy
Very light 1/16th.
Quote from: bfeist on January 25, 2022, 02:00:03 PM
I saw the first post dated Jan 23 and that it was Michael, and fully expected to scroll down and see a completed airplane. Michael, you're slowing down in your old age.
I just finished another bigger model on January 14.
However, it is true, I'm working slower to spread out the fun.
Quote from: sihinch on January 25, 2022, 02:11:00 PM
He's also getting smaller, I think! ;D
Smaller SUV. ;D
Fin/rudder: pieces cut, assembled, glued, sheeted, shaped and sanded.
Very light but very strong.
Tight and secure fit (not glued yet).
V-shaped bottom/hull: a support structure is constructed, sheeting applied, and sanded smooth.
Medium-hard 3/32" balsa sheeting at the front; 1/16" sheeting at the rear.
Starting on the wing. This will be fully sheeted when finished; hopefully light but strong. I'm doing a lot of thinking as I progress, planning the construction and considering the layout of the wiring, nacelles, servos, ailerons, tip-floats, etc. I'm working slowly and carefully so all the parts fit precisely. The bottom sheeting, upon which I will build, is cut straight so pieces can be glued together. The edges of the balsa sheets are not always straight, even when purchased brand new. The square carbon fiber tube in the photos is extremely strong.
Wing under construction.
Love your work!
Looking forward to seeing it fly, when the water becomes less solid...
Guy
I may maiden it off snow.
Ailerons constructed. Also, webbing is installed (vertical grain balsa sheet in between the ribs, contacting the top and bottom wing spars).
Nacelles and motor mounts.
Not yet glued in place.
Wing is fitted and attached to the fuselage. It's beginning to look like a Canadair Waterbomber.
amazing work Michael
I'm taking a break from working on the wing, and moving to the front fuselage. Basically, I'm building a structure onto which I will apply balsa sheeting.
A bit more work. Actually, that was a lot more work. I'm tired; that's enough for today.
It's looking more and more like the intended subject.
Beautiful work!
The front fuselage framing is done.
The fuselage is put aside, and I'm continuing work on the wing. Today: the tip floats.
I thought about building these up with a frame and outer balsa sheet, but decided instead on solid balsa, carved to shape.
I used different thickness sheets, glued together cross-grain, and then carefully carved and sanded to shape. These are firmly held onto the wing with magnets; they will release with lateral force, preventing damage. This is my solution to what is usually a weak spot on models with tip floats.
Winglets constructed of 2 rib-shaped layers of tapered trailing edge balsa, and 2 layers of cross-grain-glued balsa sheet. These will be shaped and sanded once the top wing is sheeted.
I was concerned that these would be cumbersome (in storage and transportation), and was considering holding these onto the wing with magnets, but since the wingspan is only about 4 feet, I don't think they'll be a problem. I'll just glue them on once the covering is done.
Aileron servos sit in carefully constructed pockets, in order to be removable for adjustments.
Very impressive. I like the way you built the nose.
Quote from: octagon on February 02, 2022, 06:16:58 PM
Very impressive. I like the way you built the nose.
Thanks, Rob.
Hopefully, it'll look good when it's sheeted.
Anyway, the wiring is done for the wings. I can start the top sheeting.
Will both prop run in the same direction?
Quote from: GuyOReilly on February 02, 2022, 07:57:13 PM
Will both prop run in the same direction?
Counter-rotating.
Hi Michael. For what it is worth, Rob Pike says counter rotating props should turn so that the left motor rotates CCW when viewed from the front and the right one CW when viewed from the front so that the props appear to turn into the fuse from top down. I forget why it should be that way, but I wrote it down when he told me.
That's how I always do it.
Note however, Glenn's twins are usually not contra-rotating, and they fly great.
I've decided to take an unorthodox approach to sheeting the top of the wing. I am planking it. This is my solution to the difficulties I have had in the past with accurately curving and evenly gluing down larger sheet pieces. With this method, I will simply sand the top smooth when finished. I am not worried about any loss of structural integrity that may be lost by not using single length sheets, since the carbon fiber spar and webbing have basically made this wing rigid and inflexible.
That is one great way of using up the scrap pieces and leftovers from long pieces. :D
Guy
Progress ...
I'm really pleased with this method of planking the wing. It's not as slow a process as I thought, it's not difficult, it's easier than applying larger sheet pieces, and, as long as I measure and cut carefully, the construction is accurate and fun.
Wing sheeting is complete, wing top is sanded, ailerons hinged, angled-end-ribs shaped and sanded, and attached with winglets (temporarily).
More work on the fuselage.
This is looking super cool. Awesome work, Michael.
More progress. Also using some planking instead of curved and twisted sheet.
Really nice work Michael.
The front is done, and now to start the battery compartment hatch.
Top of front fuselage.
Battery compartment hatch.
Looks Fantastic Michael!
Finlets built and in place (not yet glued).
Next, I'll probably start on the servo placement and linkages for the elevator and rudder, before closing up the rear fuselage top.
I am looking forward to seeing how you will do the water scoops and release mechanism!! :D
Guy
Servos and linkages installed for rudder and elevator.
All major construction is done. Total weight, with receiver, servos, wires, motors, props, spinners (3D-printed by David), electronic stabilizer, and 3-cell 2100mah battery, is 1150 grams, or about 2½ pounds. It still needs a battery tray and covering, so it'll be a few more ounces.
The model is disassembled and ready for covering. The 3 photos are of wing parts, tail parts, and fuselage parts.
Covering in progress.
Covering and painting is done. There are still some decorations (stripes, fake landing gear, windows, etc.) to be applied before assembly.
The striping is a mix of individually cut strips, strips from a roll, and individually cut curved sections, carefully lined up and applied. About 3 hours work, but I really like it!
Trim and decoration details are not exactly scale, but they are nice and effective.
Next I start the general assembly.
Finished!
Assembled, radio and stabilization system installed, linkages installed, power system installed, triple deflection and exponential rates set, and ready to fly.
Total weight with battery (balanced) is 1260 grams, or approx. 2 pounds and 12 ounces (44 ounces).
Now I'll wait for a nice, not-too-windy, day.
That's gorgeous. What a scratch build! Well done again, Michael! :)
S
WOW! Stunning Michael
Congratulations
Looks great! Nice job Michael!
Successful maiden on Thursday, Feb. 24.
I changed the 'windows' to a darker blue, because the light blue didn't show well.
The in-flight photos are by David.
Red spinner looks much better Michael. Congrats on the maiden!!