A non-lick lollipop!
As the wing assembly is nearly complete and ready to attach to the rear of the fuselage, I decided to do a test of the leg to fuselage mounting idea that I want to use.
I will have to have the wings and the two rear leg assemblies attached before I can close up the rear fuselage.
Considering that I am making up the build modifications as I go along, I thought it best to have this step proven, before I continue with the other three leg assemblies.
The point where the leg attaches to the fuselage, via the domed structure, has the most stress, mainly lateral stress. If this joint is not strong enough, the weight of the model would make the whole thing collapse over time, and that just will not do.
So, time for some 'over-engineering!'
My general idea is to transfer all the stress to the main internal support frame of the model, thereby reducing any stress to the body shell/fuselage itself.
First up, I rolled a very tight tube of card to a diameter of about 3mm. This was glued up and this created a very stiff rod. The point where the leg attaches to the domed assembly has a very small surface area and I was afraid that this would not be strong enough on its own. So
very carefully, I drilled out a 3mm hole in the centre of the mounting point of the leg. This hole will accomodate the end of the rolled tube and when glued in it should be very solid.
Next up, I made the domed structure that the leg attaches to. I used tabs on this, as I thought the extra card would give even more strength. I am not too worried about the roughness of the joints, as this whole thing will be sanded smooth later on. A 3mm hole was punched to accomodate the tube.
I cut 2 discs from 1mm thick card, punched out the holes for the tube and glued them inside the upper and lower pieces of the dome.
Before closing up the dome assembly, I added a little more internal bracing. Considering that the leg will be at a 90 deg angle to the mounting tube, I wanted to overcome any bending possibilities of this point.
The brace was cut to shape and glued to the inside of the dome and glued to the tube.
The dome assembly was then closed up, making sure that the short section of tube sticking out of the dome, fitted snuggly into the hole drilled in the leg. And here is where the lollipop reference comes into play.
Next up I made the assembly that attaches to the fuselage and that the dome assembly attaches to. Again, I used a card disc to strengthen the swivel plate.
The tube and dome assembly was then mounted in position by pushing the tube through the swivel plate, without gluing.
So far, so good!
Last night, I soaked the whole dome assembly in CA glue and left it to dry over night.
Later this evening, I will sand the dome smooth, and then continue with the rest of the assembly where the leg tube attaches to the internal frame.
See ya'll latersssss......