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Building Tips and technical articles. => Building techniques => Topic started by: Bob Zambelli on February 19, 2007, 08:25:44 AM
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Saturday morning, I started building my new plane, the "Tre-baccelli".
Here you can seen the progress I've made.
Span, with tips will be 64 inches
Wing is take-apart as shown. Carbon fiber rods and carbon/fiberglass tubes.
Stab span is 31 inches.
OS 26 4-stroke power.
Questions?
Bob Z.
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Saturday morning, I started building my new plane, the "Tre-baccelli".
Here you can seen the progress I've made.
Span, with tips will be 64 inches
Wing is take-apart as shown. Carbon fiber rods and carbon/fiberglass tubes.
Stab span is 31 inches.
OS 26 4-stroke power.
Questions?
Bob Z.
Bob looks like you are paying attention to my speed building classes. Looks good.
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Robert wrote "Bob, looks like you are paying attention to my speed building classes. Looks good."
YEP!! You inspired me to get off my duff and start building!!!
The entire airframe should be done by the weekend.
Bob Z.
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os 26!!! are you sure a 26 is going to pull this?
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There is no way a .26 will pull it.
Bob Z.
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There is no way a .26 will pull it.
Bob Z.
I thought you had a "typo" in your post there ("OS 26 4-stroke power"), Bob! **)
Which OS 4 stroke is it REALLY going to be?? (is there a 76??)
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First statement: OS 26 4-stroke power.
Next statement: There is no way a .26 will pull it.
Both statements are true.
Bob Z.
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First statement: OS 26 4-stroke power.
Next statement: There is no way a .26 will pull it.
Both statements are true.
Bob Z.
!!!!!!!!!!!!!!!!!! Ok, a "riddle" ?????????????????
**) **)
More than one engine?? (guessing from "Tre......")
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Bill - you got it!!! y1
I said OS .26 4 stroke power. I just didn't say how many. ;D ;D
The attached picture shows the test bed that convinced me. VD~
Bob Z.
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Bill - you got it!!! y1
I said OS .26 4 stroke power. I just didn't say how many. ;D ;D
The attached picture shows the test bed that convinced me. VD~
Bob Z.
That plane popped to mind when you said both statements were true! **)
So it will be OS "78" powered! ;D
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Alright-alright you got me laughing. LL~
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In case anyone is interested in the progress of the triple (to be called Colibri),
here are a few more photos.
I had a bit of time to work on it this past weekend.
Bob Z.
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Keep the pics coming, at least I would like to see more as you progress.
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Another update.
I cut out and built the basic fuselage last night.
Shaped & hollowed the tips.
Made cowl rings - cowls will be soda cans.
The wing fuse and # 1 pod as shown is around 10 ounces.
Bob Z.
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Last night's work - carved the top block, finished the empennage, roughed in the two wing engine pods.
Bob Z.
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Lookin really good Bob. How are you going to cover it ? Need to show off the bones.
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Hi, Leester - I'm not sure what I'll do about the covering - I'm kind of making this up as I go along.
I can't wait to finish it so that I can draw some plans.
Anyhow, I woke up about 11:00 last night and couldn’t get back to sleep.
Deciding to do a bit of work, I installed an angled plywood plate in the fuselage and then fired up the band saw.
I cut the fuselage in two pieces as shown.
I then machined the joining hardware as seen in the pictures.
Now, in addition to being able to remove the outer 23 inches of each wing, I can also split the fuselage just aft of the trail edge.
I also shaped the canopy.
I’m having way too much fun!!!
Bob Z.
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Bob: Is that spackling you used to blend in the canopy ? If so will dope affect it ?
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Hi, Lee - no, it's some sort of very light filler I bought at Brodak's.
It's the best stuff I've ever used.
Glob it on, smooth it with a wet finger and let it dry (water based, I believe)
Then, it sands like silk.
Seem to stick very well to dry balsa.
Dope does not seem to bother it.
Bob Z.
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Dope does not seem to bother it.
Bob Z.
Bob trust me on this! Coat it with CA after sanding and before dope.. As the dope is layered on it will soften and cause problems. But if you coat it with CA it will help..
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Hi, Robert - thanks for the advice. I will do as you suggest.
By the way, after the CA cures, do you scuff it with light sandpaper to remove the gloss?
Bob Z.
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""""I cut the fuselage in two pieces as shown.
I then machined the joining hardware as seen in the pictures.
Now, in addition to being able to remove the outer 23 inches of each wing, I can also split the fuselage just aft of the trail edge.
I also shaped the canopy.
I’m having way too much fun!!!
Bob Z.""""""
Hi Bob
Nice job , can you post detail pictures of the take apart fuse when you get it finished, also I am sure everyone wants to see the wing take apart detail too, this is one of the most asked question pertaining to take apart ships, and the take apart fuse your doing look like a very unique way to accomplish this. I would be curious as to the weight of the take apart components you have.
Regards
Randy
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Hi, Randy - thank you for the compliment.
I would be very pleased to post and share all the details.
Coming soon!!
Bob Z.
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Hi, Robert - thanks for the advice. I will do as you suggest.
By the way, after the CA cures, do you scuff it with light sandpaper to remove the gloss?
Bob Z.
sand with 320
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A bit more progress.
Last night I hinged the epennage and did the first complete assembly - it went together perfectly.
The weight as shown is around 16 ounces.
Bob Z.
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That would be great for a "Prewar German" paint scheme. It "reeks" of Ju-52 for some reason!
Bill <><
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Not to seem impatient Z@@ZZZ But were's the updates or where you at VSC ?? S?P S?P
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Hi, Lee - nope, I wasn't at VSC - just had a few other items creep in.
Anyhow, here are the latest shots. The controls are in and working perfectly, as is the take-apart feature.
What you see is 20 ounces.
The closeup of the trail edge shows the flap coupling system.
Bob Z.
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Thanks Bob, Great work and very interesting. Can't wait to see the 4 strokers in there.
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As you can see, the airframe is now set up with all three engines. #^ #^
In order to balance it (remember, there is around 30 ounces of engines up front!), ~^ ~^I systematically shortened the nose and both nacelles. I’m now very close to the right balance.
Since the fuselage is take-apart just aft of the flap pivot, I will completely finish the rear fuselage before determining final engine placement.
The only actual fabrication left is the installation of the engine module attachment blocks and shaping of the landing gear. :)
The complete weight – airframe, engines, all controls, wheels and props is presently
around 61 ounces. I estimate mid 70s ready to fly. y1
Notice the odd angle of the engines – there is a reason. Rotation brings the venturi up to the approximate centerline of the nacelles. This allows rigid placement of the tanks and the ability to fine tune by rotating the engines slightly in either direction for uniform running.
I would like to hear your questions, comments and suggestions on this most interesting project.
Bob Z.
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without wishing to sound like a smart ass,
Lightest props you can find .( ive got some old Mahl ? 10 x 4 'toothpick' german ones ,look like teak.
" oiled a pair with timber oil to 'feed' them .)
Id offset the fin. Flat outside , 1/8 in. along the length.
Id do the first flight on stong 60 ft lines, The second on 65 ft. (if I wasnt draged a few feilds downwind ! )
Generous tip wt. initially . Fine pitch props ( 3 or 4 in.)
The bigger the angle on the blades, the worse the plane rotates under ' Traction ' .
Mr Berringers fancy L.H. rotation Satio's Cam is Manufactured with Two Seperate Lobes.
I presume the O.S. doesnt, with the Satio you could order an unassembled cam, and with a coustom Crimping /
Peening tool , fix it with opposite lobe offset.
then youd have to figure out which prop to turn opposite.
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SO HOW DOES THE PROFILE FLY ? does it get a bit of roll if the winds a bit gustie ?
Just seen a picture of a BLACK S.M. 79 , with the postage stamp type Tri - Colour markings .
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Have you seen the Bellanca 28 / 60 Tri - Motor . . . .
M.Spencer.
Id set the inner props flat against the compresion ,so you flick them upwards ,so you dont get blood on the
aeroplane.
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without wishing to sound like a smart ass, NO!!! Not a smart-ass at all. All suggestions are welcome and encouraged.
Lightest props you can find .( ive got some old Mahl ? 10 x 4 'toothpick' german ones ,look like teak.
" oiled a pair with timber oil to 'feed' them .) I have had the best results with the APC props - heavy but they work well on 4S engines.
Id offset the fin. Flat outside , 1/8 in. along the length. The fin is actually shaped to an airfoil, flat side outboard.
Id do the first flight on stong 60 ft lines, The second on 65 ft. (if I wasnt draged a few feilds downwind ! ) I have a set of .021 x 65 foot lines
Generous tip wt. initially . DEFINITELY!!! The starter battery is the tip weight.
Fine pitch props ( 3 or 4 in.)No - I've tried fine pitch props on 4S engines but the higher pitch (6 and 7) generally give better results
The bigger the angle on the blades, the worse the plane rotates under ' Traction ' . I do not understand this statement.
Mr Berringers fancy L.H. rotation Satio's Cam is Manufactured with Two Seperate Lobes.
I presume the O.S. doesnt, with the Satio you could order an unassembled cam, and with a coustom Crimping /
Peening tool , fix it with opposite lobe offset. WAY too much trouble. I'm building this aircraft for sport and fun and will probably never compete with it.
then youd have to figure out which prop to turn opposite.
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SO HOW DOES THE PROFILE FLY ? I have done many flights with the three engined profile, mainly to test engine behavior. It is GREAT in the wind, very smooth and penetrates well. It's just a bit short on wing area. does it get a bit of roll if the winds a bit gustie ?
Just seen a picture of a BLACK S.M. 79 , with the postage stamp type Tri - Colour markings . What is an S.M. 79? Savoia-Marchetti?
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Have you seen the Bellanca 28 / 60 Tri - Motor . . . .I've heard of it but never seen one.
M.Spencer.
Id set the inner props flat against the compresion ,so you flick them upwards ,so you dont get blood on the
aeroplane. This in the only situation where I use an electric starter.
Bob Z.
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theres a picture of James Lee's Bellanca Tri - motor on 1/2 A models , ( Bellanca 28 / 92 )
on TWIN ENGINED PLANES .. robert mc Ham. posts about 30 down at the moment.
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Propellors Theres therys that the tourque of an Airscrew is the same as if the Airscrew was stationary at the relevant speed.
Its
Just on a hand launch , if there not thrown 'away' from the pilot, it can get interesting.
The Spitfire Mk. 21 pilots notes and flight test reports are interesting .
all its Foibles were cured by enlargeing the Empenage about 50 % . (not recomended for humans )
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the french had a few interesting Tri - Motor airliner / mail planes in the 30 s.
Do our renolds Numbers pan out at those figures ?
Equivilant too 200 m.p.h. on the full size 30 s Stuff ?
S.M. definatly nothing weird, but ive heard a few odd stories about these Romans ! .
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Bob,
I've been so engrossed in my own projects that I haven't looked around much to see what other guys are doing.
Your plane is way cool. The picture of the parts piled together really brings home the amount of work and thought you've put into it. I'll be coming to the Brodak Fly-in this year and I'm hoping you'll have this model there. I'd sure like to get a close up look.
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Hi, Frank - thank you for the kind words.
Unfortunately, the Triple has been sidelined due to some overwhelming tasks that must be accomplished.
As you may know, I'm very close to retirement and my new house is complete.
I now have to get my PA house ready to sell, not to mention moving some equipment (my machine shop, wood shop, three cars, a motorcycle, my Piper and many model planes) down to South Carolina.
My model aviation activity has been virtually ZERO for the last month, time which I originally planned to complete the Triple.
I hope to get right back on it in August.
Bob Z.
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Bob,
Wonderful workmanship and well thought-out desighn. Pictures are very good. It wont be short
on power either.
Ted y1
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Interesting airplane, indeed. Bob, can you get all three of those engines running
at the same time? Heheheh. Of course you can!
My God I hate monokote.. ;->
Best regards,
L.
"Whenever you find that you are on the side of the majority, it is time to reform."
-Mark Twain
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Hi Bob,
To me, that airplane is just dying to get a semi scale WWII Italian bomber paint scheme! It just LOOKS like something the Italians would have designed. (not a flame at all!) y1
I think it would just be way kewl to paint it up like that. ;D
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Hi, Larry - actually, a very good question. y1 y1
I thoroughly tested the three engine concept on "The Plane" before starting the present project.
To begin with, I hand start one engine, dial in the needle setting, and shut it down.
I repete this for the remaining two engines.
On the flight line, I top up all three tanks.
Then, using an electric starter and a corded glow driver, I start each engine, from inboard to outboard.
I then walk around in back of the plane and top up each tank, outboard to inboard.
Using this procedure, I have no problem getting everything going in under 50 seconds from the start of the inboard engine.
The Surpass engines start instantly with electric starters.
Hi, Bill - I heard about some triple-engined Italian planes, both military and civilian. One was a Marchetti as I recall.
Here is one picture.
Bob Z.
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Bob you also do great pictures and info on a project. I am still waiting on the Cardinette from Brodak. later, DOC Holliday