One last question: I see you realized the canopy/windshield prior to sheet the fuse, why didn't you wait to complete the fuse? No criticism, just curiosity .
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Joined: 2/4/2002 From: Malta, MALTA Status: offline
Hi Giacomo, I have just bumped into this thread. It is very interesting indeed especially the retract geometry. I notice that there is a lot of wood in making this plane and wonder what weight it will have at the current size. Now that you have gone through this process would you think, in your opinion, the plane would have been lighter if it was built in epoxy. Just asking
Well, the fuse at this stage weights about 980 grams which is reasonable to me. Final weight will be in the 6-6.5 kg range ready for take-off.
I don't know about the final weight of a glass fuse, but I know that it would require some bulkheads here and there and that they would add to the final weight dramatically.
I'll invest in a glass fuse just to speed up building time.
Just my 2 cents anyway .
PS Unfortunately yesterday a CL-415 crashed while on duty here in Italy and the pilot lost his life.
One last question: I see you realized the canopy/windshield prior to sheet the fuse, why didn't you wait to complete the fuse? No criticism, just curiosity .
At first having studied Bernard's plans , I had made up my mind to construct the fuse to two separate parts plus the main gear one. (...not sure though , if it was the right choice...) [foto 1 & 2 ]. Because of the short length of these parts , I was able to work simultaneously , at more than one stages. I decided not to proceed with the sheeting at that point , so as to have access to the interior of the fuse during the various construction stages : - attaching the canopy/windshield on to the cabin [foto 1] - installing the door hinges as well as the front gear [ foto 3 & 4 ] ,which is exactly what i am up to this time - installing the tail/fin [ foto 5 ] I am also thinking about adding tanks for dropping water. So ,as you can see I hope , the lack of the sheeting at this point makes it easier for me to make the above alterations.
ORIGINAL: teresos At first having studied Bernard's plans , I had made up my mind to construct the fuse to two separate parts plus the main gear one. (...not sure though , if it was the right choice...) [foto 1 & 2 ].
I preferred to build all the fuse in one piece for greater structural integrity and better overall alignment.
Do not worry, you'll be able to join your 3 sections together so they will withstand operational stresses.
quote:
I decided not to proceed with the sheeting at that point , so as to have access to the interior of the fuse during the various construction stages :
You're right, I'm waiting to sheet the fuse too, just added the hull sheeting to help with the alignment and handling of the fuse.
I'm back from my holidays, will be working on my model from mid September on.
No hurry at all, but will be glad to follow your steps in making the windshield. Waiting for instructions/pictures, again, no hurry 'till mid Sept.
Having built the main gear mock-up gave me some satisfaction but it also showed me with little regard that making it work the way it is designed would have been a painful experience.
Page 7 (scroll down to last pictures) of this 3d shows original cylinders placement:
I had to deal with it before committing time and patience to a non-rewarding matter: that setup isn't the best... for a number of reasons:
1. cylinders may (and they WILL) interfere with each other, their endcaps are larger than main body diameter 2. cylinders are a pain to fit in place in the finished model, they're a pain to fit even in the mock-up which was thought to ease things up a bit... 3. cylinders cannot be seen during operation = poor diagnostics of possible (if not certain) problems 4. if the cylinders are a pain to fit you can imagine how terrible it can be to fine-tune the linkage, and the tuning is a must... 5. cyllinders exit through a hole in the fuse and this compromises water sealing
So we have difficult installation, almost impossible setup, invisible operation and super-tight accessibility... too many bad things not to deal with them right now.
The attached pictures show what I came out with: everything is based on what I already have put together, with NO modifications to the already built fuse nor to the gear elements themselves, GIVEN the 1" stroke main cylinders that I own. Again, everything has been worked out trying not to touch anything and the simulations show that there is no interference between the gear operation and the fuselage (this is why I modeled a length of airplane cabin section).
This way, which may not be the only possible way, almost all the bugs are worked out: you can see the cylinders working, you can install and remove them more easily, no more holes in the fuse sides... it sounds good to me.
The only problem seems the little arm... this is forced by the 1" stroke of the cylinders, but remember that the not pictured locking/unlocking upper cylinder helps with the actuation of the entire system, especially at the endpoints (where the arm is at its smallest).
Obviously every feedback and/or advise would be greatly appreciated!
Oops... I didn't tell you how it works: basically the axle around which the lower leg rotates acts as a torque-rod; I designed a simple horn of appropriate geometry to connect the rod to the cylinder clevis.
I still have to deal with the torque-rod/lower-gear-leg interface but it doesn't worry me too much.
Feel free to ask.. I just realized it could not be clear enough... and that is not a fault of yours!
I still have to deal with the torque-rod/lower-gear-leg interface but it doesn't worry me too much.
This is what I came out with:
1. the rod is notched in two places to accept 2 set-screws 2. once the rod is in place and blocked the actuating horn is clamped to the rod at the correct angle given by the geometry
In the meanwhile I updated the physical mock-up to deal with the new main cylinder position.
I also mounted everything in place to check for mishaps: at this time, I'm still not able to actuate the entire system beacuse I need full-metal parts to test proper torque trasmission... I can't do that with wooden parts!
What is important to notice is that main cylinders don't stall at either endpoints and that the locking/unlocking cylinder helps a lot toward the travel extremes.
Cylinders push = gear up Cylinders pull = gear down
All cyls work in the same direction while they didn't in the original design.
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RE: Bernard Dumas' Canadair CL-215 - 
