Gear pivots
Posted: Fri Feb 17, 2012 5:26 pm
Bob, No I don't have bushings in my gear legs. Just the plain old hole drilled thru the tube. I would strongly suggest to everyone to use the solid blocks available with bushings or even just make a solid block to get more bearing surface as I am going to do before I reinstall. The only problem that I have had with the main legs is when I sheared all the rivets out of my passenger door post, when I dropped in on one ski(from about 6' up-you know the event) while avoiding an icehut and a snowmobile. (Remember I am the initiator of the double rivet row up the door posts!) (and maybe Rob didn't have power on when he went in the lake??!!)When I inspected the gear closely I had bent the leg about 7" up from the axle. Not very noticable unless you put the 7" section on a table and held it tight to see the other end 3" off the table! The pivot hole was also elongated about 50%, I suspect just from the upward force of impact at about 3g's. This is why I am going to solid blocks, although I am probably a little worried this will cause the bigger bandaid problem. That is,before the leg took the damage and now it may cause airframe damage! Hopefully I have enough time in these things now that I will never find out! I will also note for others reading this, that I rarely fly off pavement! My strip is grass, although smooth enough that Howard comes in for gas every week in his amphib,but most places I go are rough grass strips, farm fields etc. (even my first trip to the Rebel Ramble saw me in a farmers field sitting in a combine waiting for the rain to stop!)
As for the rubber biscuit gear, the pucks are a real pain in the ass to keep in place even with cuppedwashers. They ooze out all the time. I see on the real thing rip off(well it is different, from the shine it's made out of 2024) the pucks are retained by 4 guide rods. These will work for about 4 landings then the pucks will be out rubbing on the guides and be chewed up. Rubber pucks have a shock absorberefficiency of 60% compared to 50% for steel springs. 10% better but hard to control in the way we need them to work. The main thing when using steel is not to bottom them out, or they work like a slide hammer in the body shop. Mine need to hit at 4 1/2 g's to bottom. At that rate its not the plane I'm worried about. The nicest use off rubber I have seen is on my UTVA 66 Yugoslavian Ex-Military Planes. The gear pivots similar to the rebel but compresses 3-2"thickX5"x10" rubber blocks, out and above the leg. You can drop it in from 5 0r 6 feet and not even knowyou landed.They are retained by 2 bolts thru the center line of the blocks. Unfortunately the rebel dosn't have the structure to adapt this or it would be done already!
As you know Bob I have a complete set of photos, from start to finish and various other shots from start to finish on every step in a Rebel. If someone is stuck I may have the picture you need to get going again! As far as I know, outside of the factory, I have put more quality Rebels in the air (or back into the air) than any other builder. As our ad reads we've been there, Done that!
Blue Skies, Wayne
As for the rubber biscuit gear, the pucks are a real pain in the ass to keep in place even with cuppedwashers. They ooze out all the time. I see on the real thing rip off(well it is different, from the shine it's made out of 2024) the pucks are retained by 4 guide rods. These will work for about 4 landings then the pucks will be out rubbing on the guides and be chewed up. Rubber pucks have a shock absorberefficiency of 60% compared to 50% for steel springs. 10% better but hard to control in the way we need them to work. The main thing when using steel is not to bottom them out, or they work like a slide hammer in the body shop. Mine need to hit at 4 1/2 g's to bottom. At that rate its not the plane I'm worried about. The nicest use off rubber I have seen is on my UTVA 66 Yugoslavian Ex-Military Planes. The gear pivots similar to the rebel but compresses 3-2"thickX5"x10" rubber blocks, out and above the leg. You can drop it in from 5 0r 6 feet and not even knowyou landed.They are retained by 2 bolts thru the center line of the blocks. Unfortunately the rebel dosn't have the structure to adapt this or it would be done already!
As you know Bob I have a complete set of photos, from start to finish and various other shots from start to finish on every step in a Rebel. If someone is stuck I may have the picture you need to get going again! As far as I know, outside of the factory, I have put more quality Rebels in the air (or back into the air) than any other builder. As our ad reads we've been there, Done that!
Blue Skies, Wayne