Caproni Ca.42 (Full Version)

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jchumley -> Caproni Ca.42 (2/23/2004 4:51 PM)

This is a plane that you don't see all that often.

I started this discussion with a question in the Aerodynamics forum where I received a lot of excellent advice. I think now it is more of a Sratch build subject. I am building it for the upcoming Dawn Patrol Games this spring at CCRCC in southern MD.

http://www.charlescountyrc.org/wwi_profile.htm
http://www.charlescountyrc.org/recon_info.htm

It is based on the construction techniques of the Fighters for this series designed by Rich Foch. Flat botom airfoil, Wing struts glued into the wings etc. I was originally going to go with three Saito 30s but BMathews in the aerodymamics forum has convinced me to loose the middle engine and its attendant weight aft of the CG and necessary ballast in the nose (probably at least 1 1/2 lbs total). Since the middle pod is bolted on, I can always try it both ways.

The wings will be a solid structure, all glued together. The booms and center pod are detachable.

The very tall tail skids are still a questionmark. THey need to be tall so the bottom wing and bomb housing clear the ground. They need to be light because I don't want any extra weight back there. Any ideas?

I will stretch the nose an inch or so to put the battery as far forward as possible along with any lead that I need to add.

Any other comments or advice is welcome. I have Solartex to cover it with and the only paint will be on the Italian colors on the rudders.

I should finish framing it up this week and have it ready to fly (if it will fly) in two or three weeks if I don't run into any unforseen issues.

Jeff



BMatthews -> RE: Caproni Ca.42 (2/23/2004 8:53 PM)

You're right, that much music wire would weigh a ton!

I know it's not high tech but I suggest bamboo for the skids. Get some good stuff from outdoor plant stores or good quality chop sticks for the material. It's flexible but very fatigue resistant and lighter than most other options I can think of other than custom molded (because of the curves) kevlar and epoxy layups. Bind the parts at the joints with high strength carpet thread and then soak the binding with thin CA to lock it together. Bits of music wire on the lower ends will act as anti wear shoes or add small wheels for steerable landing gear. In fact if your runway is paved then the wheels, steerable or fixed, is a good idea or it'll be too easy to ground loop it. For grass the bare skids would be fine.



dicknadine -> RE: Caproni Ca.42 (3/5/2004 4:28 PM)

suggest you make a take off dolly, skids fit into slots, NOT attached. this will get you off the ground. landing--DO IT on the grass. would suggest leaving the dolly on till you have a couple of flight over with. it helps calm the shakes. dick



jchumley -> RE: Caproni Ca.42 (3/8/2004 11:00 AM)

Rather than a dolly, I am going to add a removeable long skid like an avro 504. If it tries to tip over, the skid should help keep it upright. If it DOES tip over, I suspect I will be rebuilding the tail section. The rudders are pretty vulnerable.



dicknadine -> RE: Caproni Ca.42 (3/11/2004 7:25 PM)

and I thought my scratch built planes were complicated. congratulations. dick



jchumley -> RE: Caproni Ca.42 (3/23/2004 3:35 AM)

Just posting the latest pics. Might be in the air in the next two weeks. (I am rushing to be ready for an event on April 4) Still a good bit to do but mostly busy work. Have to brace the tail skids, set up the main gear, install servos for the tail surfaces and throttles etc.

Jeff



BMatthews -> RE: Caproni Ca.42 (3/23/2004 6:31 AM)

She's looking great.

I'm just thinking about how tall this model is and in looking over the 3 views. Seems like the engines are going to be a LONG ways above the ground. You may want to do the landing gear in such a way that you can cheat a little and have the wheels come out a bit further forward than true scale. On grass it may be a noseover machine. I noted that the 4 wheel gear arrangement has the forward wheel quite a way in front of the balance point. That's a good thing and it may prevent the nose overs that I'm thinking of.

Still it would be good to have a plan B in the back of your mind.

I'm looking forward to hearing about the final specs and how it flies.



jchumley -> RE: Caproni Ca.42 (3/23/2004 3:16 PM)

Thanks Bruce:

THe Bamboo tail idea sure was a good one. I bought a big pack of bamboo skewers and found a dozen or so that are good and hard and straight. THey don't weigh much more than balsa. I am going to heat and bend the end and run one straight down from under the rudder and lash and glue them together. I put hard points in the horizontal stabilizer a few inches from the tips so I could run wires from the hard point, down to the skid and up to the opposite boom for side-to-side bracing.

THe wing "boxkite" is very rigid and I don't think I will need any landing or flying wires but when I add all the heavy pieces I may change my mind.

I am going to extend the main gear a bit but I am only using the front sets of wheels for now. I am running short on time and can go back and add the others later if necessary.

I too am concerned about nosing over. I plan to add temporary extended skids for the initial flights. If it goes over, the rudders are very vulnerable. Getting it put together (you can pick it up and nothing falls off) makes me realize how short and tall it is!

With no servos, engines or battery it balances at about 40% of the chord. I will probably have to add lead but not too much. I am using an 1800 ma battery that will add a good bit of weight to the nose.

Jeff



BMatthews -> RE: Caproni Ca.42 (3/23/2004 6:36 PM)

It sure sounds like you've got it all covered already. That's good news about the empty balance point too. I kind of feel like the "uncle" waiting on the birth of a nephew since you used some of my suggestions :D Of course in the end the decisions were all your's but if I was able to help then all the wear and tear on my fingers is worth it.

If it flies as good as it looks you'll have a winner for sure.



jchumley -> RE: Caproni Ca.42 (3/29/2004 8:22 PM)

Well Bruce, six days to the Dawn Patrol Games and here she is. If it is going to fly in the event beginning Sunday at 11:00 am, it will probably have initial flight testing Sunday at 8:00 am. Its going to be close but it is possible.

The little steps take the longest time!

Any hints for bending bamboo? I have tried boiling it and also tried soaking in amonia and bending around a hot iron. The stuff doesn't want to bend more than just a little bit!

Jeff



BMatthews -> RE: Caproni Ca.42 (3/30/2004 1:10 AM)

The problem is that it needs to be hot all the way through to bend. If you can keep the bend area in boiling water it may be hot enough. Alternatley if you use a heat gun on high with the little air scoop on the end so it sort of contains the heated air then it will probably get hot enough.

One thing for sure, every time I've bent bamboo you KNOW when it's hot enough. Below the critical temp and it's springy like steel wire. Hit the right temp and it turns into a limp noodle.

If you're brave and have a good supply of the bamboo you could even try a propane torch. Start far and move in SLOWLY to give the bamboo time to heat all the way through evenly.

Of course all MY bamboo work so far has been with little 1/16x1/8 pieces or smaller for parts of my rubber old timer and scale models so you're on your own... :D

If it just does NOT seem to want to cooperate you could split the bamboo into flat stripes, bend it and then laminate it back together with some epoxy.

PS: I wish I could be there to see it fly. This is going to be one to turn heads for sure. All the best with the weekend.



BigglesFliesUndone -> RE: Caproni Ca.42 (4/1/2004 12:42 PM)

Hi there. I just found this thread doing a google search for info on Capronis. Wish I had found it earlier as perhaps we could have helped each other ?? Reason is I too am building a Caproni (is there any plane not been modelled ??) However, Im going the easier way with a Caproni Ca 3.4 it has only two wings. Its just a prototype (6ft span) for a larger more scale model assuming it flys OK
Ive attached a pic of the build so far. Like yourself I have opted for only two working engines .25 glow with the rear pusher a dummy. Best of luck with your maiden and please keep us informed how it goes.



jchumley -> RE: Caproni Ca.42 (4/1/2004 2:17 PM)

Very nice. Looks like the real thing.

You are building much more scale than I am but I too am planning a larger detailed scale version. This one is for an actual combat type event where it will tow a ribbon and be protected by a flight of fighters against a flight of enemy fighters. The risk of damage is high. That, and the fact that I have only had about 3 months to work on it in my spare time meant that I could only go semi sport sorta kinda scale. I hope to fly it this Sunday. I decided to go with three engines after all. It looks like it will still come in around 6.5 lbs and be a real floater. Can't wait to fire up the three saito .30s. should sound really cool. It should probably fly easily at considerably less than full throttle. (if it flies at all!)

You have an advantage with the Ca.3, there are several good reference works on it. I have Gregory Alegi's Windsock Datafile on it and it is good. THe Ca.42 is not nearly as well documented. I have one book in Italian that shows some detailed construction drawings of the center nacelle, the landing gear and tail skids and some of the strut mounting hardware. anything that I can't document I will use the Ca.3 documentation. I am not sure whether I will go 1/8 scale (12' wingspan) or 1/12 scale (8'). I can tell you that I will be tired of making ribs by the time I am done. Even for this one which has much wider rib spacing, I had to make over 150 ribs!

I have heard that the Caproni Museum in Trento, Italy has a model of a commercial version of the Ca.42 but have been unable to contact them about it. WHen I get to designing a scale version, some time spent with that model would be very helpful.

Your rudders look great with all the wires and braces. How did you attach the bracing rods to the center rudder without inhibiting rotation and what mechanism did you use to fit the rudders to the elevator?

Jeff



BigglesFliesUndone -> RE: Caproni Ca.42 (4/1/2004 4:02 PM)

Hi again .. nice to communicate with someone with a similar interest in the unusual, especially WW1 era which I prefer. I was aware of the plane you are modelling but decided on the "easier" CA 36 for the following reasons .. its easier to balance with the front gondola . battery (and unfortunately a little lead) will go right up front. More stable landing gear ... is it a tricycle or taildragger [:)] and last but not least ..better documentation. I too have the datafile from Albatros and using its 3 vu as basis of the plan.. also a website has over 50 good pics of the one in an american museum (Patersons ??) . Ive been at it on and off for about 2 months .. although it looks detailed .. its all quickly done (see pic) Origionally it was going to be 2 x .15SC glows .. but now I think that may just be a tad marginal so will probably have to get two .25 but that is still debatable as its only to find out its flying characteristics before doing a 108" version powered by two 52 fourstrokes. Not sure of the size of yours ?? but if about 6 -7 ft and around 6 lb ?? perhaps be aware of the power of three .30 two strokes ? I have a partial built beaufighter at 6.5 ft span ..weight about 8-9lb designed for two .32 two strokes !! so keep the throttle down. Someone also told me of a chap that won an AMA control line event with a caproni 3.6 at 72" span and 6.5lb powered by two .25's so Im in the right ball park. Controls are as the original eg closed loop. Instead of pulleys I just put the rigging through brass tube bent to right angles with a "gentle" bend works very well and no slop !(see pic)
Ive a few ideas on the proper scale job I will start in a month or so so perhaps we can swap ideas on the "real" models..cheers Donny



BigglesFliesUndone -> RE: Caproni Ca.42 (4/1/2004 4:08 PM)

Here is another unusual model I made ..just for interest ..A Caudron GIII ..9ft span powered by 90 Four stroke. I had originally intended making the GiV which is the French equivalent of the Caproni ca3 but a certain ProfLooney (he visits here sometimes) persuaded me to do the Ca 3.6



Xfactory -> RE: Caproni Ca.42 (4/1/2004 6:06 PM)

Not a Caproni but a WW1 twin engine bipe, My hansa Brandenberg 67" span electric powered.



BMatthews -> RE: Caproni Ca.42 (4/1/2004 6:08 PM)

That's lovely looking work there Biggles. And all that for just a quick "tryandsee" model? You REALLY must post pics of the serious one then.



jchumley -> RE: Caproni Ca.42 (4/1/2004 7:13 PM)

I have seen photos of the control line Ca.3 you mentioned. It was in one of the fairly recent model airplane magazines. May an AMA magazine. It looked really good.

The Ca.4 series has about as many variants as there were planes built. The one usually designated ca.41 looked more like an outgrowth of the Ca.3 series with a longer gondola with the same shape and a very tall nose gear. THe pictures I have seen don't include the "coffin" bomb rack of the Ca.42. The ca.43 was a ca.42 on floats!

THe gondola shape seems to have varied alot on the ca.42 with most of them being kind of ovoid in cross section but I have seen at least one photo with a gondola more like the one I used.

Interestingly, the Italian book "Gli Aeroplani Caproni" by name-escapes-me has a different numbering system. WHat I have been calling a ca.42 they call a ca.41 and so on. Don't really know which is correct.

They were made using Fiat, Isotta Frashini, liberty and even some kind of rotary engine. I would love to have seen a group of four or five full size ones taking off!

I hope I can land it. It looks like a nose-over waiting to happen.

The first photo is the Ca.41 that has a gondola similar to the Ca.3 series.

The second is a Ca.42 and it appears to have a torpedo under the wing. the RNAS had 6 of them that I believe were used for anti submarine duty.

The third is anther ca.42 showing the more standard bomb enclosure with additional bobms strapped on the outside.



BigglesFliesUndone -> RE: Caproni Ca.42 (4/1/2004 8:14 PM)

Its a common problem with these "old birds" in that they were almost all individual and you really have to just pick the one you want to model for scale. There are many variants of the Ca 3.6 but because I have pics of the restored one in USA my true scale one will be of it.
http://www.wwi-models.org/Photos/Ita/Caproni/
Sorry I have only seen a couple of pics on the net of the CA 4 and it was on floats as in one of your pics so can offer no info. I have managed to find a pic of how the rudders were mounted on the tail of my model. I used piano wire (about 1/16" dia). The two outer rudder posts were tied and glued to the rear boom posts. The tailskid silver soldered and screwed to the boom gives additional strength. the underwing struts are kebab skewers but also add some rigidity. the centre post has a small piano wire crossmember soldered to the bottom that fits in a groove in the tailplane It also has the diagonal braces soldered at half mast so its all very sturdy. It does require the functional rigging to stop it "whipping" Rigging (not in pic) is carpet thread. Its not too heavy but in a moment of shear laziness I made the rudders solid and thats why I need the lead up front [&o] The rudders just slot down the masts (centre one was different because of the braces) and are held in place by the stays at the top of the mast.

I like the Brandenberg idea of lectric...mine is going to be covered in oil and yuch. I just realised the Saitos are four stroke ?? far better than my greasy twins !!

You may think it over detailed for a couple of flights then in the bucket .. but its all quick easy stuff . Example the flood lights look good ?? easy ..two cup washers glued to ball joint fittings .. 5 secs work. the rigging so far is functional so has to be there. the gun turret was about two hrs work soldering fine piano wire then wrapping some car body repair mesh on it. the weathering is just chalk smudges .. so its not really much work . Its all made from scraps left over from my main winter project .. a 1/4scale spad VII .. now that was detailed .. Id post a pic or two but dont want to polute your Caproni thread ... look forward to your flight report .. be ready for it to climb steep and fast on lift off. should be great on a calm day .. but if windy ..watch out !!

PS if you are still trying to bend kebab sticks (bamboo ??) do it over a candle flame



Xfactory -> RE: Caproni Ca.42 (4/1/2004 8:22 PM)

I normally bend bamboo over a soldering iron, try it.



BMatthews -> RE: Caproni Ca.42 (4/1/2004 8:38 PM)

quote:

ORIGINAL: Xfactory

I normally bend bamboo over a soldering iron, try it.


Same here, but with the iron driven off a lamp dimmer to hold back the temp just enough to prevent scorching the surface too badly. Set it so the surface JUST browns but does not char further.



jchumley -> RE: Caproni Ca.42 (4/4/2004 10:24 PM)

After all that work getting the bomber ready for today...

Cancelled due to wind! I ws up until 2:00 working on it and up at 6:30 to finish it up. The wind kicked up as predicted around 8:30. Its just as well. I couldn't have really flown it today anyway. I don't have much experience mixing chanels and getting the three throttles mixed together (the pusher is on throttle (JR #1) and the others are throttle-gear and throttle-spoiler. I haven't been able to mix out the spoiler knob for some reason but I mixed out the gear switch.

I digress. I can't tell how much is weighs as my electronic scale only goes to 5 lbs. I tried leveling it with blocks under one wing tip and the scale under the other, reversing the setup and adding the two numbers but it wasn't close. Way too light. I guess I will have to buy a bigger scale.

It is really cool though the way the three rudders move together and the three ailerons and the long elevator. It really neads pull pull in two places on the elevator to keep it from twisting. maybe later. Couldn't fly but I did take it to the hobby shop . They got akick out of it.

Maybe I can fly it next week.

Jeff



BMatthews -> RE: Caproni Ca.42 (4/5/2004 1:41 AM)

Whatever you do don't loose the "edge"... :D

I'm not sure but I think you can add all three points sort of like they do with axle scales. But the model needs to sit at the exact same attitude the whole time. Make a couple of blocks that are the same thickness as your scale. Sit the landing gear contact points on two blocks and the scale. Take readings with the scale juggled around to all three points and add up the three totals and you should get the total weight...... I think.



BigglesFliesUndone -> RE: Caproni Ca.42 (4/5/2004 7:12 AM)

Sorry to hear it was too windy .. but at least the pressure is off you now, and you have time to make sure all is well before its first takeoff. Must sound great with the engines all running. Hopefully ..my maiden will be in two or three weeks time. Its now looking a bit better with the top story on. Just the wing panels and engines to go.



jchumley -> RE: Caproni Ca.42 with engines installed (4/6/2004 8:50 PM)

Here it is with engines.

Several of the club members work at the Pax River NAS designing, building and testing RPVs. One of them is evidently the ultimate RC test pilot. I am going to ask him at tomorrow nights meeting if he would be willing to test fly this beast.

Better him than me.



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