FDM Sailplane main gear legs by SkyRider

Last crawled date: 3 years ago

I have printed the fuselage and tailplane and am currently printing the wings. Instead of Carbon Fiber, I've been using lightweight brass or aluminum tubing (enlarging holes as necessary on my drill press). Overall, the design is super sturdy and I plan to put in an ArduPilot system on board (I also put in a more powerful motor and a 3 bladed prop (couldn't find what was specified, but found the equivalent in the US). One thing that bugs me is the landing on belly as I don't have a prop with folding blades, so instead I need legs. For a nose strut you can bend up a torsion spring leg from hanger wire. I put in a slot to place a piece of bent wire to support the leg. I recommend printing these as they are, on their side so that the bending lines are in the direction of lift (up and down). The wire should absorb most of the impact. For all of us in the US, 2" wheels will be fine (in my case, that clears the prop from the ground). I don't expect it to take off on its gear, but at least when it hits the ground, the prop will be protected (a little). You'll have to position the gear based on your own build, but I will have it in section 3 just about at the trailing edge of the wing due to Weight and Balance. This is as yet untested, so caveat emptor, but it's a start. One note: as you can see, the groove for the embedded wire goes through the wheel axle: obviously, you don't nee the wire to go that far down, but if you glue in piece below the axle hole, countersink your axle screw, that does the job. What I will do is enlarge the hole and use a larger screw, drilling a hole THROUGH the screw which allows the wire to be continuous. This will make everything that much more rigid.