Trusses in the ceiling serve to prevent the floor joists from twisting.

The trusses in the wing serve an entirely different purpose, they tie the uppeer and lower spars together, making the wing more rigid in the vertical dimension.

Sure thing,

they also increase the torsional rigidity (shear resistance) of the structure preventing the wing from over flexing along both its length and diagonal axis. The stresses on a load bearing floor are akin to those on a wing under high acceleration along a moving axis (e.g., a snap).

In terms of design though (not necessarily engineering), the analogy between the joists and ribs and trusses and shear webs struck me as interesting. The main difference being that these floors have their trusses in between "spars" (structural beams) rather than against them.

Somehow I don't think my floor would fly very well however...unless of course I hollowed it all out and put a good engine on it.

Hello David, the GMS 47 is not as user friendly as an OS and needs a longer break in, but once is properly tuned and broken in, is very powerfull and reliable. It is made in China and is true ABC. Some like them, some do not, I have two and love them

Regards
Francisco

Very nice plane, Doxilia. And I have heard that it flies nicely also in .25 size.

Marian

Que tal Marian?

Thanks for the positive comments. I've had that one "on the table" a little too long and it's time for it to spread its wings. I should have some further updates soon. I'd be curious to hear from anyone who has built a reduced version of the Tsunami. They must have scratch built it?

I also see that you expressed interest in Rafa's Picorare (10 size Tiporare) project. If you're building a reduced scale Tiporare, I'd love to read the details as this idea (and the Tiporare) goes back a long time in my memories (I provided the reduced scale plans here on another thread). I will be starting some Tiporare builds next Month and hope to have a build thread on that project.

Rafa too still has to provide us with more details of his project!

Saludos, David.

P.S. If you'd like to write in Spanish you can do so via a PM. Hablo espanol.

Francisco,

thanks for the info on the GMS. We'll see how the ST fares and then I'll make a decision regarding a more powerful engine.

... an update. I feel like I've reached a milestone. After just about 12 years since I started the build, all the major components are built and ready for the final assembly.

I completed the wing over the last couple of nights: Panels joined, center sanded to fit saddle, bolt plate installed, center section glassed & ailerons hinged. I decided to correct the outboard aileron section which was 1/16" out of alignment by sawing through the TE/aileron stock joint half way and re-gluing at the proper angle. Turned out to be quite simple.

Next up will be mounting the wing to the fuse followed by stab alignment. Once all major components are fitted to the fuse, I'll begin with the radio install. I like to do this before I finish the model as potential hangar rash may arise from this operation and it allows one final touch up to the airframe prior to covering.

I'm throwing around a few ideas for the finish but haven't decided yet. Given the dipping temperatures I'm leaning toward covering the entire model rather than painting the fuse as I had originally planned. Painting the fuse would be quite a bit more laborious and I'm hoping to have this project RTF by the end of the month.

Any suggestions for a covering scheme?

Cheers, David.

The project is gradually moving ahead...

I'm in the final assembly stages and construction details (wing chin block, pushrod exits, etc.)

Tonight I got the wing mounted on the fuse. It was a little complicated since the front is held down by two dowels and the rear by two nylon bolts. Simple enough in principle. The tricky part is that the holes in the wing are drilled first and then matching holes in the fuse former are drilled. The catch with this is that there is no accurate way of marking the location of the holes in the former. The instructions discuss a transfer method whereby the dowels are inserted to 1/16" from the LE, paint applied to the tips and the wing moved forward to touch the former. If one is using a snug wing saddle however, this method doesn't work since one cannot actually seat the wing without two things happening: 1) the paint smearing on the former and 2) the dowels popping into the wing never to be extracted again. [&o]

So instead what I did was to mark the locations for the holes on the former with a pencil with the wing TE not seated in the wing saddle but rather still at an angle with the dowels propped up against the former and the TE resting on the fuse bottom. I then translated the distance the TE would drop when seated to the rise of the dowels on the former. I then drilled holes at these locations on the former. With the dowels sanded to a slight conical shape on the external part, they tighten into the holes as the wing is seated. It worked..., phew!

As another tip when building I would reverse this order prior to building the fuse. I would first drill holes in the former, build the fuse and then transfer these holes to the wing LE from within the tank compartment - much easier and more accurate. Of course this requires leaving the fuse tank area bottom off until after the wing/fuse mount. Knowing the right position for these holes in the former helps so I'll measure things and comment should it come in handy for anyone building a Tsunami.

I'm now gathering all the accessories and items needed for the radio installation. This part is always fun!

More photos coming soon.

I've started work on the radio layout and linkages. I was hoping to be able to side mount the elevator servo in order to avoid any differential throw on the elevators but the fuse is too narrow in the area I need to install the servo. Technically I could install it in the front third of the radio bay laterally but it would make for a rather awkward radio layout with the RX in the rear under the elevator pushrod. The battery would also need to go behind the CG which I suspect is not desirable. I'll upload a photo of the layout planned on the ply radio tray once it's ready.

I was planning on installing a DB 8 oz tank but I had a Hayes 8 oz tank which has nice dimensions for the tank compartment and uses a really convenient setup for the fuel tubing including an optional (sealed) fill nipple. Given the easy access to the carb tube, I'll use simple two tube tank pipes.

For linkages, I'm using the forked dowel and rod pushrod I made for elevator, P-P for rudder and a standard DB flex cable for throttle. Aileron servos will be mounted with standard steel pushrods and metal clevises - nothing fancy. I am going to try some DB control horns on elevators and ailerons which I haven't used before consisting of 4-40 screws and end plates on either side of the surface.

Radio: I'll be using my fairly new Spektrum DX7 with an AR7000 RX, 4.8V 1100 mAh NiCd pack, 1 JR NES-501 and 4 JR NES-507 servos (now discontinued) which had their bushings replaced with BB. The 507's will go on Ailerons (2), Elevator (1) and Rudder (1); the 501 on Throttle.

I hope to have the radio tray ready and installed tomorrow.

Following that, a little paint (canopy & engine bay) and on with the covering.

Here we are at the end of the month and I'm not quite finished... oh well, it's good to set a goal. (After all my son turns 6 only once!).

Some progress...

For the radio installation I decided to do something a little different (unconventional?) this time. Since my fuse wouldn't accommodate a side mount of the standard size servo, I went ahead and mounted it vertically. I first laid out the components in the radio bay to check for spacing and the possibility of relocating the battery to allow proper balance. There's a 5/16" square spacer at the bottom of the bay which divides the compartment in two. The elevator and rudder servo are located behind this divider in a staggered fashion - elevator to the side and rudder centered for the P-P setup. The battery (BT), receiver (RX) and throttle servo are in the forward compartment. I positioned the throttle servo to allow me to place the BT and RX on either side of it.

I made a servo tray out of 1/16" ply and made the necessary cutouts for the servo's. The two receivers (Spektrum 2.4 system) are installed on the tray on either side of the servo with the battery and switch hidden underneath the tray. I usually protect the RX with foam and place it off the tray but given the shape, cables and antenna's on the AR7000 I did something a little different - I first made a RX tray out of lite-ply and used velcro to attach the RX to this tray. The RX tray was then soft mounted to the servo tray with double side foam tape. The entire servo tray will be mounted to some hardwood beams using servo grommets. Hopefully this arrangement will dampen vibration on the radio components. The battery tucked under the servo tray is wrapped in foam rubber. I may wrap the main RX in foam rubber too using some narrow tape to avoid covering the velcro holding it to its tray.

I'm using GP pushrod exit guides for the elevator rods and P-P wires. I've also made progress on the tail feather fairings as well as the wing LE/fuse fairing (photos to come) - small items but required quite a bit of elbow grease. I had forgotten how badly epoxy/micro balloons sands even when the mix is quite low in epoxy. I have to go and get some resin.

Very nice radio layout David. Have you decided the colour scheme ?? will you apply film or some other kind of covering material ?

Saludos
Francisco

Thanks Francisco. I think it will work nicely. We'll just have to see about balance once the radio is in. The only inconvenience is having permanent servo/tray rails in the bay as it prevents the tank from being removed if the front rail is too far forward (given the lack of a hatch). I think if I place it just in front of the throttle servo, I should be ok. Otherwise I have an idea for removable rails...

Actually, this morning (before coffee...) I woke up with a rough idea of what I was thinking of in terms of colour scheme. The (wiggly paper) sketch should explain it. I'm just not sure how well the waves will work with the lines of the model. It'll be easier to tell once I get started. Typically I start with an idea and I end up with something different. If anyone has any comments or suggestions... they are most welcome!

For finish I decided to go the Monokote route given that we're hovering around 10 degC outside (October is here...). I also want to get started on another rather daunting project (I hope to have a thread on that one) so I can't afford the time to paint the fuse as I had hoped to do. And, after all, this model is more of a sport plane than a show stopper (mine is certainly not especially given the minor damage suffered!) The only exception though is the wing bottom center section. I'm going to use a technique used by Mike (8178) on some of his models where the center is painted and the outside panels are covered. This should make for a smoother (wrinkle free) wing center bottom given the compound curves and should also do nicely in covering the glass cloth. I'll be using two different primers (the first for coverage and the second for Monokote match colour prep) and basic Lustrekote jet white. The canopy and cowl will also be painted black.

By the way, you'll notice that for fun I thought of putting the model name onto the wings and fuse using the Greek alphabet (not actual Greek)!

On another note... the airframe is finished!

I've left the final 600 grit sand for after I'm finished painting the wing bottom, canopy and cowl. I'm hoping the weekend will bring some sunny weather...

It's always a pleasure to take pictures at this stage of a build... especially 11 years after the plans were first unrolled!

Hope you like the pictures. David.

And a couple of interior shots...

I decided to assemble the tail feathers onto the fuse prior to covering in order to make some fillets between the fuse and feathers (ehm... not done yet) making for a smoother finish. I'll also cover the tail feather/fuse transitions with strips prior to covering the surfaces hopefully making for a more seamless finish (at least I can pretend I'm painting ).

My list of to do chores is still 15 items long! Onward... got to get that Monokote ordered.

David,

Very, very nice built. About one year ago I was in touch with a friend from RCU discussing about Tsunami. Maybe he has missed this thread, but I will send him a PM ...


Marian

Marian,

Thanks again for the compliments. I'm really happy it's getting finished. I only started this thread 5 to 6 weeks ago so your friend would definitely have missed it back then. It'd be great to hear from others who have or are planning to build one of these. Juno is supposedly releasing a .60 size version, maybe it will have foam wings and retracts?!

While looking at a flyer containing monokote colours I saw a newish ARF biplane from GP on the same page and it struck me how similar my proposed scheme and the covering on the ARF was... [&o] Either we're more influenced by what we see subconsciously or the scheme I have in mind is a good one. Nonetheless, it was a little disappointing to see an ARF with my pattern! Well, in the end it won't be quite the same and the colours will be different.

These are the colours I have in mind. Don't know whether I need one more...

Your pics bring old memories to me, back in 2001 when I was building mine. BTW yours is looking fantastic so far, I'm sure you will end up with a very nice looking and flying Tsunami, no matter if there is an ARF with a similar colour scheme out there, yours will be always better

Saludos
Francisco

Francisco,

I'm sure the memories must be good ones and I'm glad you're enjoying this project. BTW, when down south I'll be sure to contact you should I be in the GTO area. I'd love to see your local field. What are you flying these days?

In any case, thanks for the inspirational comments. I've had to wait for the weather to cooperate in order to paint. Last week we had a series of cool (not cold by Great White North standards) days and rain but Sunday and today finally brought about some 15-18 deg C weather - enough for spot paint work.

I finished painting the cockpit in flat black and have moved on to the wing. I glassed the slightly modified cockpit (front has instrument panel area rather than what struck me as an unfinished area in the design), sanded and used high build primer before the flat black. I'm not using fuel proof paint in this area as it will be sealed by the canopy and the paint allows several coats to be applied in short intervals (1 minute dry time to overcoat!). A few hours worth of work and good enough for a sport cockpit.

The bottom of the wing was also (clearly) glassed - first with 6 oz cloth followed by a wider 3/4 oz cloth and sanded smooth with the wing sheeting. I've started applying primer but of course..., I ran out. [] I still need to do some filler work along the seam to insure a smooth transition and plenty of sanding (I shouldn't be showing this until it's finished properly! ). Then, since I'm not far from where I want to be with the primer I may switch to Lustrekote epoxy primer before the white coats. Sand, sand, mask, mask, paint, paint... [:-]

Hopefully October will provide us with a few more days of ~15 deg C temperatures in order to finish the paint work and allow moving on to the covering. As I was painting, I have to admit I was tempted to go back and glass the whole fuse and shoot the thing with paint. It would probably look a lot nicer given the sheeting accidents incurred in it's youth! Mmmm...

Well, hopefully I'll have wings and stabs to cover.

Hello David, I'm currently flying an Ultra Sport Plus, what a nice plane BTW. Im posting a pic of the tsunami (the ugly guy it's me ) at my local field and the Ultra Sport +

Saludos
Francisco

Haven't posted in a while so I thought a little update would be in order.

Frank, that's a nice US+! I assume it's kit built? I'm curious, why don't we see the engine out of the right side? Is your engine mounted inverted or perhaps it's electric? Are you using one of your GMS engines?

On the Tsunami front I've made a little progress but things slowed down while I waited for Monokote and Lustrekote to arrive (some trim Monokote is still missing). With Lustrekote in hand, yesterday I had a miraculous (for this time of year) 21 deg C and was able to continue priming the wing center section. I have one more priming session for the engine cowl and the final coats on the wing then it will be white paint.

While I wait for another good sunny day, I think I'll move ahead with the tail feather covering. I want to finish the wing before covering the fuse to insure I still have a good fit and to follow the wing trim contour.

In other good news I made my first yabe purchase with a great deal on a new OS 46 FX - half price. I'm planning on running the ST S40 with a pipe in first flight tests and if I feel more power is necessary, I'll switch to the OS, otherwise I'll need to find a good home for the 46 (the finish on OS engines really is nice).

Hi David. I built the US+ per plans, with the engine inverted. It has a Magnum 52 XLS (2 stroke) and with all the power this engine puts out, the plane has trully unlimited vertical, it hovers easy with throttle at 2/3. As you can see, I like chinese engines, I have several and all of them work very well and last for a long time. My favourite is the Mag 52 XLS. Believe it or not, it is more powerful and reliable than my beloved Irvine .53 [X(]

Very nice Frank! The US+ really does look like a cousin of the Tsunami. I like inverted cowled engines but I'm not crazy about bulging mufflers sticking out of an otherwise aerodynamic smooth plane. I'm not sure why there aren't more designs similar to the US+ made for rear exhaust engines. For that matter, I'm not sure what happened to rear exhaust engines in general - there seem to be very few on the market nowadays.

A Tsunami update... with the painting of the cockpit, cowl and wing center section complete (I got really lucky with the weather last couple of weeks - today we expected snow!), I ran out of excuses not to begin covering the model. I should have the base layer on the flying surfaces complete tomorrow allowing me to re-fit the wing and make any necessary adjustments to the fuse.

Photos of progress coming soon!

Yesterday we had 25 deg C in the sun, extraordinary for this time of year! Of course, after work, I come home and end up working in the shop rather then flying. Today, Saturday, I'd like to be flying, but of course it's pis***g rain. Oh well, there's some party to go to at least.

To keep the momentum up, a few pics on the covering. I've completed the first (base) layer on the empennage and control surfaces and almost finished the wings - just missing the top right panel. After that, I'll retrofit the wing (minor adjustments) and I should be able to move on to the fuse.

One thing I've been thinking about is whether to add some wing fillets to the fuse - classic pattern style, if you will. If I do, I better do it now before covering [:-]. Anyone care to comment?

First pic shows fillets on the wing underside to transition the paint into the covering - not bad but I think there's probably a nicer way yet. Tail feather fillet detail.

David.

Wing and Stab bottom...

I'm not sure about this one, but not having used Lustrekote before, I had higher expectations in terms of color match. The paint has a warmer "cream tone" white while the Monokote has a "blue-gray tone" white - both are Jet White and Lustrekote primer was used under the paint. The paint is new while the Monokote is old (~10 years) but was still shrink wrapped. Either the film color has changed since and today's Jet White is different, the film degraded in color (I find this hard to believe for plastic) or, simply, the match is what I'd call "close".

I'll have to ask about this one. Anybody else have similar results?

Wing tops. Finish coming together...

When the trim is complete I wanted to apply some decals to the wing bottom. However, I also want to clear coat the wing bottom center section. I have never applied clear coat on top of decals applied to film covering. Will this work, or will I end up having to spray the entire wing or worse, with a mess?

Might be moving back to fillet work on the fuse tomorrow evening with the wing finished. Any recommendations?

Thinking about this color too... any takers?