About to start a scratch build from a 3-view...if there are plans out there, I can't find them!
Want to build a foam fuse with glass skin and I'm not sure what kind of foam to use. (I lent my copy of Keith Sparks' book on building foam model airplanes to Andre and he's still in Trinidad)
Formers will be balsa and I'm planning 3or 6" EPS foam wafers between...
Recommendations gladly received! ;D
Styrofoam is light, sands poorly, cuts poorly and shatters easily.
Styrofoam SM (the pink stuff) is heavier, tough to sand lightly but removing large amounts seems easier to me, and is tough as heck.
If your hot wire cutting the pieces than I have no input as ive never done that.
sorry that's all ive got but looking forward to some of the other answers!
Cut some balsa formers and EPS wafers...3" to try the materials and assembly procedure. Glued using canopy glue as recommended by Dave Henry at Pinnacle. Seems to hold, shape and sand okay...suggestions from experienced types appreciated.
Formers are 3/32" balsa sheet and I'm using my magnetic building table so I can keep pressure on the developing fuse while the joints set up. So far I've rough cut the foam with a hand saw which isn't as accurate as I'd like ...I'll probably have to add the cost of a band saw to the cost of this model...will a bandsaw cut 3" foam fairly cleanly or does it just shred the foam?
There's foam snow all over the work area floor already! Have to quit for now, I'm out of balsa.
The band saw will cut very cleanly with an 18TPI blade.
Jack.
Thanks Jack. Are we starting scratch build classes next week?
A few more wafers with Ed's size gauge (Lost the betcha can't have only one bet!) including the first obvious mistake that I've caught.
Used a cut edge for the surface that goes on the plan for wafer#4. It wasn't as flat as I thought and it doesn't sit flush with the table top. I'm going to leave it for now, try to fill it later and look for a bandsaw so I can cut usable edges.
Can't start the scratch build until the wood kit is available.
Jack.
I even cut foam with a 3TPI blade.
You will still have dust Bill but it will all be under the bandsaw.
The bandsaw will be useful for other things as well. (Slicing meat for sandwiches, trimming your fingernails and toenails,
cutting off your ring like Simon had to do, Resizing your cat etc) You will wonder how you ever got along without it.
Do not cut carbon fibre or your blade will immediately be dulled.
Ken
Why not use a simple hot wire? It's a LOT less messy. I use SIG nichrome wire (http://www.greathobbies.com/productinfo/?prod_id=SIGSH135 (http://www.greathobbies.com/productinfo/?prod_id=SIGSH135)) hung from the ceiling next to my work bench. It acts like a bandsaw - with NO dust. If I recall, 12 volts across a 24-inch length works perfectly for cutting blue foam. I think Rob Pike is pretty knowledgeable on this subject.
Andy
I started building a 1/7 scale Mig-3 many years ago using a method very much like you're doing there. My goal was to experiment with balsa forming around compound surfaces. I started with a built-up framework which was to be the internal skeleton of the fuselage. I then covered it with blocks of blue foam, between the formers and carved and sanded to the final outside shape I wanted. I then soaked sheets of balsa in water and ammonia until their cellular structure weakened and I was able to form them reasonably well over the fuselage form. I then wrapped the assembly with lots of rubber bands and tape to hold the balsa in place until the wood dried out. After the sheet wood was removed, it held the compound curves quite well. I then removed all the foam from the wooden framework and the next step was to glue the sheeting to the structure... but that's where I stopped. I still have the 80% framed up Mig-3 waiting for my attention, in that state. Even the wings are almost finished with four segment flaps and retracts. Maybe I'll get back to it one of these days.
Anyway, yes, foam cutting it easy and quite fun once you get a cutter set up. I need to do that myself so I can cut some racer wings. It's been a long time since I've done any foam cutting (6 years). However, I wouldn't use a hot wire cutter directly over your final shape formers as the final foam form would be a straight line approximation of your curved shape (when I cut the Sandringham fuselage segments, I made the templates slightly larger than final shape knowing that I would be sanding the high points off after assembly), PLUS, the foam usually sinks in from the templates slightly as it melts away from the wire. I would simply use a Home Depot utility knife with the snap off blades that are about 3/4" wide. I use those knives a lot for reno work and they are sharp and can be extended out about 3". Just slice away until your shape is very close then sand lightly to final shape. Blue or pink foam is easier to work with but is, as I recall, more than double the weight of white foam. Even regular white foam is heavier than Sig aircraft foam (if that's still available). I used the Sig stuff in the wings of my Sandringham.
Your progress so far looks great! It's nice to see some building technique experimenting!
Thanks for the suggestions, humorous and serious! They're all appreciated.
I have a foam cutter which I'm planning to use to cut wing blanks to be balsa sheeted. I'm gonna need some serious suggestions about which airfoil to use as the 3-view is no help at all on that one.
The foam cutting problem I'm trying to solve is how to cut perfectly straight cuts with a face perpendicular to the factory cut top and bottom of the 3" sheet.
Think I'm going to try a fine tooth blade and rip fence on the table saw first. I need lots of straight flat edge for the gluing surface of each half.
Today's progress...we're up to 11oz...I'd hoped for less. The structure is just over 36" long...diet time! Both of us! Rough sanded, a little filling on the low spots where my utility knife went overboard.
looking good Bill... not sure what it will be but i do know it likes beer. So something Canadian I'm guessing ;)
Now that I DO know what the model subject is, I'm more excited to see the build progress. However, I'm not sure about the Canadian content.
I'm ensuring "Canadian" content with the beer...alas, the aircraft is again Italian. It's going to be a Piaggio P180 Avanti...now semi-scale. The fuselage moved about 1/4" part way through the process of adding foam wafers (maybe too much Canadian content) so it's now about 1/4" longer than my 3-view thinks it should be. Luckily the mistake occurred in the centre section where the fuse is a cylinder, not where it tapers so I will have a "stretched" Avanti. Picture of a standard Avanti below. As long as I can make the same mistake on the other side I think it should be okay.
While we're on the topic of cool Italian airplanes, Bruce Weaver is building a Savoia Marchetti S55x which is a really nifty waterplane, so support me in pestering Bruce to post his build! Should be an interesting model!
Started putting the Avanti half fuse on a diet by hollowing it out...foam definitely makes my short list of messy materials now...I've got foam snowflakes everywhere in my house including on my clothes and even found some...well, I'll leave that to your imagination. This morning I started using coveralls and an old pair of shoes which will stay in the work area but a bit of too little, too late. Goggles and I'll look like a hazmat dude!
I think I'll try building the second half pre-hollowed!
Maybe I can up the Canadian content this way,
A beautiful subject.
During the summer one frequently passed my house. I can hear it approaching because of its very unique sound. The twin Turbo prop pusher has a very "high performance" sound that I just love.
"Bruce Weaver is building a Savoia Marchetti S55x which is a really nifty waterplane, so support me in pestering Bruce to post his build! Should be an interesting model!"
Oooooo.... Why didn't I hear about this last night?!! Very cool. Yes Bruce, PLEASE create a build thread so we can follow along!
And Bill. I'm disappointed. I felt special being "in the know" about the Piaggio ;)
Quote from: Ededge2002 on January 09, 2014, 11:59:19 AM
A beautiful subject.
During the summer one frequently passed my house. I can hear it approaching because of its very unique sound. The twin Turbo prop pusher has a very "high performance" sound that I just love.
Ed,
Thanks for your presentation last night, it must be nice to play with such fascinating toys and get paid for it!
I've lived about a km from the south end of Buttonville's main runway(33/15) for the last 30 years. I enjoy the parade of Cessnas and Pipers from Toronto Airways and Seneca and occasionally something really interesting lands or takes off. Amongst all the training school traffic I've seen Vintage Wings' Spitfire and a CF-18 do a low pass, the Snowbirds do the same in formation and a Canadian Forces Globemaster take off! I know when there's something special by the sound and the one that gets me running(staggering lately) to the window is the Piaggio. You're right...twin pusher turboprops with five blade propellors have a sound all their own...especially on approach as they seem to keep the throttles at least 1/2 open(should that be 50% for a turbine?)...music to an aviation buff's ears!
Once I found out what it was, I got even more interested and had to try to build one! 3-view was the only way I could find.
Well, re-charged by Andy Hoffer's enthusiasm for RCing, airplanes and life in general, I started the right half of the Piaggio fuse. As you can see, maintaining "Canadian Content " has been ...enjoyable. After chatting with Robert at the meeting and becoming increasingly frustrated with the foam "snow" which is now everywhere in my house, I decided to hollow out this side of the fuse before I put the wafers together. Turns out only slightly less messy, but hopefully lighter. Got about half of the right side glued together...looks a bit lumpy...time to walk the dog and maybe work on some Canadian ...content ;D
Love what you're doing here, Bill- great choice of subject, and I'll bet the sound of yours will be as unique as the full size. Regarding the foam mess- if you don't do it already, keep your trusty shop-vac handy and vacuum the stuff on the bench and yourself every few minutes rather than at the end of a session. Should help keep the foam off the poor dog and out of your underwear. :)
Tom
Quote from: Tom M. on January 11, 2014, 06:36:07 PM
Love what you're doing here, Bill- great choice of subject, and I'll bet the sound of yours will be as unique as the full size. Regarding the foam mess- if you don't do it already, keep your trusty shop-vac handy and vacuum the stuff on the bench and yourself every few minutes rather than at the end of a session. Should help keep the foam off the poor dog and out of your underwear. :)
Tom
Tom!
Great to hear from you! I've followed your bug build with envy...another Muir Masterpiece in the making! Great stuff!
Too late for the underwear but maybe The vacuum will help the dog...I thought that was dandruff!
I've started reading about trimming canards and understand enough to know I have no idea what I'm doing...so,
before I get too far I'm going to build a small model, probably a glider to test CG,canard incidence...so much to learn!
Attached another picture of a full-size...the thing really is beautiful...apparently the only straight lines on the fuse are windows and doors...very organic looking and apparently provides 20% of the lift!
Also pictures of the right fuse half...tomorrow we'll see how the two halves fit!
Not sure if there are meant to be 1 beer per section?
Great build Bill. It's looking fab.
The Piaggio Avanti is loaded with 'Canadian content'. It is powered by two Pratt & Whitney Canada PT6A, -67A I think, turboprops. I have heard it flyover as well and it does have a unique sound partially because one engine drives it's propleller one way, the other in the opposite direction
Bigstik
Phew! Thanks John! Thought I was going oto have to rely on the beer for Canadian Content! At Simon's suggested rate, I should be on the second case! So far there are 32 sections or wafers...16 on each side.
I finished gluing the second side late last night but I had to take the last four sections off the right side and re-do them. Will trial fit the fuse halves tomorrow.(later today actually)
All it needs is some fins and it would look like a foam carp! Lots of filling and sanding to go but the fit of the two sides will do. Gonna leave the sanding and filling until the wing and tail components are trial-fitted. Compared the weights of the pre-hollowed and post(wafer gluing)sides and the pre-hollowed is nearly 4oz lighter. The addition of Canadian Content continues...
I think it looks more like a Pike, Bill!
But it does look super awesome!
Of course it looks awesome if it looks like a Pike ;D
But I'm concerned that the beer bottle collection is out pacing the fuselage construction...
Seriously though, it does look fantastic! You're giving Mad Man Michael a run for his money. Great work!
I doubt I'll ever build or fly as well as MMM but I'll probably drink more beer along the way...sorry, add more "Canadian" content ;D
I've changed to top view on the workbench to have a run at the wings...gulp...they are really small! I may deviate from scale somewhat here...mach speeds are not what I'm after...any suggestions for an airfoil? I really don't know enough to make an informed choice on my own and unless someone knows a better choice, I'll probably opt for Clark Y.
Apparently the full sizer uses a special airfoil which allows the small wing area. It also appears to use a variation of Fowler flaps to increase wing area and decrease approach speed and I'm not planning flaps...if I did, I'd probably have to add the flaps on the canards which deploy when the main wing flaps are deployed...bigger wing should solve some of this.
Building this way involves making many of the decisions that would be thought out for the builder if plans, instructions or a kit were available.
Should have included this in the last post but I'd sure appreciate some thoughts from experienced builders about wing construction and mounting. I have little (no) experience building this way and I'm largely "winging" it ::)!
I'm planning to hot wire cut foam blanks and balsa sheet them. Plans are to build five sections; a centre section through the fuse with no dihedral, left and right fuse to nacelle sections with scale or close to scale dihedral(this much will be permanently attached to the fuse) and removable sections outboard of the nacelles. Main spar and drag spar will be cut from ply...thickness? WS is just under five feet and my target weight is under six pounds (maybe a tad optimistic)
I'm not sure my plan to permanently glue the centre wing section in is the best...so far none of my plans are cast in ...epoxy ...except the fuse halves which were done with canopy glue anyway.
Any hints appreciated...
I think you need more beer, Bill!!
Here are some Clark Y images. You could modify it by giving the bottom some lifting characteristics.
Jack.
Quote from: Papa on January 13, 2014, 05:18:46 PM
Here are some Clark Y images. You could modify it by giving the bottom some lifting characteristics.
Jack.
Looks like a whole
school of Pike !!!
A
My approach for choosing airfoils sections for scale models (not that I've done it very often) is to browse through Profili until I find a section that looks reasonable close to that shown on the three view. In the case of the Sandringham, I did that then chose to reduce the thickness to 15% from the scale 18% or 20%, as I recall, to reduce drag.
However, anytime I've done this, the scale section looked reasonable so I didn't see any risk in this method, but if you say the Piaggio has a strange section, then going with the good old Clatk Y is a great option. I remember Keith Shaw saying that he would use the Clark Y on all his planes.
Clark Y it is...the 3-view is no help at all. I will incease the wing size slightly...my plan is to add 1/4-1/2" all the way around. Hopefully that will not lose the character of the full size wing. Thanks Jack, Rob, for your help. I'll cut the templates today and dust off(there even more dust than usual right now!) the hot wire stuff.
There should be no dust Bill cause you're vacuuming every few minutes, right?
Tom
Quote from: Tom M. on January 14, 2014, 06:13:42 PM
There should be no dust Bill cause you're vacuuming every few minutes, right?
Tom
Well, a lot more frequently tha before your earlier post!
Cut some templates for the wing and started to lay it out on the magnetic building table. Used Jack and Rob's suggestion and used a Clark-Y airfoil. This is really easy to work with...the bottoms are flat and sit nicely on the table! (Unlike my last scratch built wing which had a scale symmetrical airfoil and wouldn't sit still on anything!)
Increased the wing approx. 1/2" in chord and span. It still looks ridiculously high aspect ratio!
Used 1/8" ply for the templates and I got tempted to cut a bunch of balsa ribs and frame and sheet the wing with balsa but I think I'll stick with the original plan to hotwire foam cores. I may not even sheet them for the first few flights until I get the CG and incidences right...foam's easy to fix!
Bill,
How does the wing section transition from the center section to the outer portion. It looks like an abrupt change. Is the step hidden under the nacelle? You'll have to consider the structural consequences of this set-up when designing the wing. You'll have quite a stress riser there.
Robert
Rob, Thanks for noticing...I need all the help I can get with the wing (everything else too!) design! Plan (not yet cast in epoxy) is to run a spar or spars (3/16"?) through the centre section, angling to create the 2-3degrees dihedral where the wing joins the fuse. I will either cut the ply spars as single pieces or gusset the angles. This section will remain attached to the fuse and will include the nacelles. Wing sections outboard of the nacelles will be detachable...I might rethink the detachable part if I go for the flaps outboard of the nacelles.
I will be thrilled to have my plans revised or re-written by anybody with a great build and fly track-record like yourself. Hoping for suggestions!
Bill
Back to the build I today. (Too busy yesterday trying to "work with" the club photographers! Hard work! They're demanding guys! Well, one of them anyway!)
Started building the centre section (one section, three foam pieces, three spars) of the wing...at least a trial of this part. As you can see from the increase in a Canadian content, this was hard work and involved a lot of head scratching and bottle opening.
Anyway, pulled out my hotwire cutting stuff and after a discussion with Andre who knows about electricity (I don't), I discovered my power source is kicking out AC current...better consume the Canadian content after I do the hotwire cutting and buy a new power source before I electrocute myself and/or burn the house down!
Managed to get the three centre wing pieces of foam cut and slotted, the spars cut (balsa for now, ply later) and trial fitted with about 3degrees dihedral. Choosing the Clark Y airfoil has again proven a joy...everything in the bottom lines up in one plane!
Now that I know some of the problems trying to build the wing this way, I'll probably go back and do it again
more accurately.
Any suggestions appreciated, especially how to cut the faces of the centre section at the right angle to match the three degrees dihedral of the outer sections... I'm still "winging" it!
The model is looking great Bill and I love the form. In your comment about finding CG and flying characteristics you might take a look at the multiplex sonic liner. Its not a match for your plane but it might give some insight. I think your concerns of the high aspect wings will be resolved. High aspect ratio wings make proportionally more lift at less drag than there stubbier relatives. All plusses for you in this case as less power will be required to push it through the air allowing less power system weight!
http://www.google.ca/search?biw=360&bih=293&tbm=isch&sa=1&ei=O1LcUtDwHIywqwGJhICADg&q=multiplex+sonic+liner&oq=multiplex+sonic&gs_l=mobile-gws-serp.1.0.0i24l2.26868.31978.0.33473.16.15.0.1.1.1.171.1754.1j11.12.0....0...1c.1.32.mobile-gws-serp..4.12.1666.meWVv44dmns (http://www.google.ca/search?biw=360&bih=293&tbm=isch&sa=1&ei=O1LcUtDwHIywqwGJhICADg&q=multiplex+sonic+liner&oq=multiplex+sonic&gs_l=mobile-gws-serp.1.0.0i24l2.26868.31978.0.33473.16.15.0.1.1.1.171.1754.1j11.12.0....0...1c.1.32.mobile-gws-serp..4.12.1666.meWVv44dmns)
Wow! That is one wonderfully unique configuration! My browser went straight to the images and...wow! Gonna see ifj I can still find one! The general layout is similar to what I'm trying to build.
Thanks for the link. Good to hear from you!
Trial fitted the wing. Lots more work here but I wanted to see the inboard part of the wing in place. Time for bed.
That wing sure does look small but it's looking very cool :)
Now go nurse that hang-over ;D
Hi everybody!
About Ben, Andy and Bill, I've finally come to this forum. I am also building an Avanti and am just before the maiden. In the Avanti Simprop is the CG located 484mm from the tail tip forward in front of the main wing. But where the CG on our model? I dont know. :-\
I'm curious how the Avanti continues to grow. ;)
Here is my first taxi test outside my flat:
Piaggio P-180 Avanti - Taxi test in the backyard (http://www.youtube.com/watch?v=w20Bpnq64mE#ws)
welcome to the forum!... and the plane looks great!
Hi Martin!
Welcome to TEMAC's forum! I think you are one of our first if not the first international poster! A few club members have read your thread on your Avanti (several times for me) and are really impressed. I have used several of your ideas already in my model. Can you post a link to your Piaggio build thread here? It translates into English fairly well with Google translator.
I've also realized your modelling skills are way beyond mine. I'm really impressed with the way you skinned the fuselage of your Piaggio! You and a few others who post here build museum quality models...mine look best when they're flying and some distance away!
Since I started the Piaggio, I've been in Florida to escape our cold winter twice and out snow flying here when the weather allows it so my Piaggio model is progressing slowly. I'll post later today or tomorrow to show progress to date.
Again, welcome!
Thank you for your warm welcome. You praise me so much that I get red cheeks! ;D
I have started 3 years ago to build planes with Depron. In total there are 4 ready to fly models and Piaggio, which must still learn to fly. Each aircraft was complex and difficult so I had to learn very quickly. I started with the Messerschmitt Bf 108. The Messerschmitt consisted of only four strips of wood and some Depron. Total spartan built. But she flew!
Messerschmitt Bf 108 Taifun (http://bit.ly/Mm5l1U')
Historie - Messerschmitt BF 108 Taifun - Eigenbau aus Depron - Baubeschreibung und Maiden (http://www.youtube.com/watch?v=V1QRG9Y4Tjw#ws)
The next was the Norseman. In this plane, I had already installed more wood. But she was very small.
Noorduyn Norseman UC-64 (http://bit.ly/1baYMs4')
The Focke Wulf Ta 154 was my diploma. Inside were Retracts and two motors. Split flaps via one servo. Everything very compact.
Focke-Wulf Ta 154 (http://bit.ly/1aLdWa2')
Focke Wulf Ta 154 - Eigenbau Depron - Baubericht (self made, building report) ), Maiden, 2.Flug (http://www.youtube.com/watch?v=sTYFEIN-ANE#ws)
And my masterpiece was then the Dornier 335 Extremely round surfaces, retractable landing gear, a pusher propeller and a tractor propeller, melted canopy, lights and so on.
Dornier 335 (http://bit.ly/ZVcrd1')
Dornier Do 335 Pfeil - Baubericht, Building report, scratchbuilt with Depron / Balsa, Third flight (http://www.youtube.com/watch?v=av99C1jMpos#ws)
The Avanti is in my opinion not so hard to build, but the curves of the hull make it difficult to work. Whether that keeps everything so that I have built there, is only still show. Just the landing gear will be put to the test. For the planking I used halved 3mm Depron. This I have blown with a hot wire. I came by a forum member on it. He had shown me. In the thread of the Norseman you can see that .
You say that you're slow? I am also very slowly this time. Otherwise, I was always ready at 10 weeks. This time there are five months! So everything is normal with you. ;D
Here is my building thread: Piaggio P-180 "Avanti" (http://www.mpx-easystar.de/forum/index.php/Thread/9779-Project-2014-Eigenbau-Piaggio-P180-Avanti-II/')
It's all a matter of practice. My first model looked terrible. So I sold it. I loved the Messerschmitt, but I no longer flew with her and so pleased today someone else about it. Do not be so critical of yourself! ;) :D
Wow, Martin! Those are amazing models. Congratulations!
Quote from: sihinch on February 09, 2014, 01:22:40 PM
Wow, Martin! Those are amazing models. Congratulations!
They sure are! Mine won't be in Martin's league but his builds are still an inspiration!
Managed to find an hour today (after Andy and I tried to fly at ROGO in a snowstorm!) to muddle away at the Piaggio. It's the first time I've tried building a model this way and everything's a trial...with frequent errors.
I'm presently cutting the roughly shaped fuse to accommodate the front wing, main wing, battery, rudder and retracts. Right now it seems like going backwards to move forwards... :(
Like Martin, I've increased the size of the front and the main wing from scale...I built the saddle for the front wing at about 5 degrees positive incidence to the main wing saddle. The idea is the front wing will stall first, drop the nose (gently we hope) and present a gentle stall.
I now have to create the anhedral for the front wing which in my mind is crucial to capturing the character of the full sizer...but that's for next session
Quote from: Wingnutz on February 09, 2014, 11:04:20 PM
... Managed to find an hour today (after Andy and I tried to fly at ROGO in a snowstorm[/b]!) ...
With a view to providing
full disclosure and keeping our members from inadvertently misinterpreting the implied plural "
we" and the implied qualifier
"tried", I am compelled to add that
"some" of us went home with nicely drained batteries after
many successful ski-based flights, graciously photographed by Bill. ;D
Ice Man Andy
Front wing anhedral of 7 degrees underway. With the front wing at 5+degrees incidence to the main wing and 7 degrees anhedral it's taken some more head scratching but it's too early in the day for bottle opening! Family wedding coming up and a whole pile of other stuff making it hard to find time for the Piaggio. Andy, I deserve to be called to task on my ambiguous reporting of snow flying but here?
Hey Bill. Is that Canard full flying? In other words, does the whole thing rotate to control pitch, or does it have separate control surfaces?
Rob,
As I understand it, on the full-sized Piaggio the front wing serves two purposes. In normal flight, it is a part of the aircraft's three surface lift system. The front wing or canard, the main wing and the tailplane all generate lift allowing the design to employ a main wing that looks ridiculously small for the fuse. My main wing, the canard and the horiz stab/elevator will be larger than scale.
The second function of the canard is to act as a counter to the main wing flaps. Main wing flaps are aggressive with regular flaps inboard of the nacelles and fowlers outboard. With the main wing so far back, deploying the flaps creates significant pitch down which on the Piaggio is countered by a control surface on the canard. This surface only moves down and only when the main wing flaps are deployed.
I think I've got that correct but if I haven't, I'd be happy to be corrected. I attached a three view and a photo of the canard.
I'm still debating whether I want to add a scale flap/canard system on my model.
Yes. That photo of the front answers my question. The canard has separate control surfaces. That makes things easier to build.
You mentioned that the control surfaces on the canard are only to counter the pitch effect of the flaps. Is this true? My understanding of canards (which is very limited) is that the elevators are on the canard. However, after a quick Google images peak, I now see this particular aircraft has a full flying rear stab that would provide pitch control, so maybe you're right. :)
BTW, while looking at pictures of the full size I was impressed with how small that main wing is! Yikes!
That is correct. The front wings stabilize the aircraft when the flaps of the main wings are down. The level control is carried out via the tail. The fact that each wing generates lift, the main wing can be so small. I am also impressed that the main wing is so narrow. The Avanti is not a canard.
Hi Martin,
Good to have you on the thread! It's an honour to have such an accomplished modeller posting!
I too have read that the Piaggio Avanti is not really a canard. I've also found the Avanti listed as a canard.
Is it because front wing, main wing and horizontal stabilizer all lift that the Piaggio is not a canard?
Forgive me if you've already considered this but would building a small simple model of your larger model help to get the centre of gravity (focus) in the correct location? When my model is closer to completion, I'm going to try the model of a model approach to establishing CG.
Thank you Wingnutz for your your flattering words. :)
Now it passed a few days and I have important news:
My Avanti was on Sunday on the runway and should really stand out for their first start. But that was duly wrong. Wrong C/G, too much wind and the flaps should not have been extended. But see for yourself in the video. Now I have received mail from your continent and now I know that the C/G should be 3-4cm forward of the wing edge. The next Sunday I'll test that again. Unfortunately, something broke. The front wing was touched, the nose gear off, the servo of the nose gear broken, the main landing gear loose and the air deflectors at the rear were broken. Everything is already repaired. On Sunday it will be 9 ° C at 7km / h wind. Perfect conditions! Just as ordered.
I will report.
Greetings!
Piaggio P-180 Avanti - first start attempt goes wrong - Erster Startversuch schlaegt fehl. (http://www.youtube.com/watch?v=s-dyjZPQYsE#ws)
Ah, what rotten luck. Sorry.
Good luck with the repairs, I'm sure the next attempt will be successful.
Thanks for sharing your CG learnings. I'm sure Bill will be grateful. What a great example of RC spirit.
Martin,
I am again impressed...this time by your honesty posting the maiden flight video! The good news is you've learned how to make it better while the model looks to be in pretty good shape and repairable!
Your flying field looks as bumpy as ours...no wonder your retracts had a hard time! I'm helping my club to install a geotex runway at our field this season so the scale models will have a smoother ride for take-offs and landings. Until that's done my Piaggio will be hand or bungee launched.
I am preparing for a family wedding next week and haven't found much time for my Piaggio. I will post when I have made some progress.
Best wishes for the next flight. Your Canadian fans will all be rooting for you and the Piaggio and cheering when you and the model have a successful flight :D...keep us posted!
Yes! Keep at it, Martin! Your Avanti looks SO nice, and I'm sure the next attempt will be successful. Great work!
Thanks to all! ;D
I will report on Sunday what happened. What a great forum! Thank you! :D
2 Try and perhaps last: FAIL!
The Avanti rolled very nice and straight and also gently rose high, but then followed by a tilting movement, which was not to control. A gyro would have maybe done, but in the split second that was not possible absolutely. There was a rollover to the right and the impact on your back. Well ...
Landing gear bow and main) back out, front wing off, tail off, dent on the back, is cracked wing. Actually, no huge things, BUT IT ANNOYS ME! This stupid thing has to fly!
So far so bad. I have to go cry now first. : (
Here a short video from my attempt: https://www.youtube.com/watch?v=lkIabhGw4O0 (http://www.youtube.com/watch?v=lkIabhGw4O0#ws)
So sorry Martin. You have to keep at it because they say "third time lucky!"
Good luck with the repairs. Don't give up.
Martin,
I looked at the video about 10 times and here is what I suspect:
1) from the time the plane started the take-off roll to the time it passed where the photographer was standing, the "up" elevator was significant. (on a plane with the elevator up front, when the trailing edge down the effect is "Up"). It may have taken off prematurely.
2) the plane rotated (nose up) and then was corrected down. All the way along I doubt there was enough speed to lift off.
3) the plane first yawed to the left and was corrected but then over-corrected to the right. Some planes that wallow left and right (The Cub is notorious) are usually tail heavy. Double check the CG and correct to nose-heavy. A tail heavy airplane will wallow, a significantly nose heavy plane will not take off. So I always start off nose-heavy.
4) Increase the take-off speed. The biggest problem is that with two pusher motors in the back, there is no prop wash over the elevator and very little over the wings. I would try to keep the elevator neutral on take-off or even a little "down" to keep the nose down and get the take-off speed significantly higher than what you had when you took off. Speed= lift=control.
5) the grass was very bumpy. I would swallow my pride and put larger diameter wheels on the plane until after the first successful flight. If it has retracts, disable them. It will allow you to get a higher take-off speed and smooth out the ride.
6) I would put more exponential in the aileron or reduce the throw by about 20%. The correction to the right was very violent when there appeared to be marginal take-off/flight speed.
Correction: I notice from an earlier photo in the thread that the canard is fixed and not used as an elevator for pitch control. The opinion still stands because there is little prop wash over the tail and elevator. I would reduce the elevator throw by about 20% as well since it seemed to have more than enough authority in the video.
Why does it look like the canard has an "up" incidence to it in the video? Should it not be at 0 degrees?
For what it is worth.
I would love to read an evaluation of the video by Pat M.
Good luck.
Frank
Quote from: Frank v B on March 02, 2014, 08:24:41 PM
Martin,
I looked at the video about 10 times and here is what
Correction: I notice from an earlier photo in the thread that the canard is fixed and not used as an elevator for pitch control. The opinion still stands because there is little prop wash over the tail and elevator. I would reduce the elevator throw by about 20% as well since it seemed to have more than enough authority in the video.
Why does it look like the canard has an "up" incidence to it in the video? Should it not be at 0 degrees?
For what it is worth.
I would love to read an evaluation of the video by Pat M.
Good luck.
Frank
Finally got time to watch Martin's second take-off...noble but sad effort...Martin, we feel your pain. We've all been there.
Frank, FWIW, in response to your #1 and correction above, I'm wondering if the full sized aircraft uses the front wing flap (inasmuch as it is only extended when the main wing flaps are extended) for take-off? Anyone know?
Also, on the full size aircraft, I think the front wing has a higher AofA than the main wing so the front wing stalls first and drops the nose causing the plane to accelerate back to safe speed.(assuming enough altitude!) My front wing is set with a few degrees more incidence than the main wing.
Martin's struggles have solidified my plan to build a small simple model of the Piaggio to try to establish CG in a practical rather than theoretical manner...but so far I'm pretty much all talk.
I haven't found much information on where people think the Piaggio's CG should be. Even if I do, I'm going to increase all three lifting surfaces and I'm guessing that is likely to move the CG anyway. Can't see a better way to get the CG located than a model of the model with everything proportional to the full-sized "model"
Hi Bill,
Noticed that you are using a magnetic build system. Are the sets available locally?
Bigstik
Quote from: jabiggerstaff on March 12, 2014, 02:12:19 PM
Hi Bill,
Noticed that you are using a magnetic build system. Are the sets available locally?
Bigstik
Hi John,
Sorry for the slow reply. If the magnetic sets are available locally, I don't know where.
I read up on the idea on a website called Airfield Models. The coated steel sheet, I bought locally at Metal Supermarket (if memory is accurate) in Scarborough, the wooden square corners I cut from particle board and I bought 100 magnets from the supplier mentioned on Airfield Models. I like the magnetic system but I still use a board and pins for a lot of stuff.
Thanks
Bill this project seems to have slowed a little so I'm going to post a photo of Canadian content inspiration for you!
Ed, you couldn't have picked better inspiration! ;D
For a number of reasons, the Piaggio project has essentially stopped but after three days battling a cold from the couch, I'm feeling ready to get back at it! Will post as I go.
Here I am again! ;D I've noticed three errors: The propellers are too large. They swirl the air on the elevator so much so that the rudder can not grab. The control surface of the elevator is too small. The front wing does not bring sufficient effect, so that the fuselage does not lift. The C/G was now too far forward. 3cm from the front edge of the main wing is too much. Now I'll test it with 2cm.
Now the Piaggio has been repaired, eliminating the errors and now I wait up to perfect weather conditions.
Third attempt to start the Piaggio P-180 Avanti (http://www.youtube.com/watch?v=3QhoG52BdW8#ws)
Martin,
Go for it. Good luck in your next attempt. We are cheering for you.
Never give up!
Frank :D
Martin,
I am in awe of your determination and energy! As Frank says, we are rooting for you and the Piaggio!!! Si bellisima!
When you have the CG right, please let us know...I think you're close to getting it perfect.
Do you know how much positive incidence the front wing has relative to the main wing?
Are the motors mounted to provide upthrust or downthrust?
I have paused my Piaggio project to re-plan, re-build and re-focus. Will let you know when I get back to it.
Good luck with the next flight!