New Y/A F/A-18 Hornet Build
02-10-2017, 05:40 PM
#101
Thanks for the CG feedback, that's encouraging. Likely a case of overthinking things during the build. Hehe. I guess i bought myself a bit more space for gear now.
Last edited by smchale; 02-10-2017 at 05:42 PM.
02-11-2017, 02:50 PM
#102
Thread Starter
Hello,
I'm working out the engine installation options. The instructions were built around a Jetcat P-180 and Y/A bypass. I'm not using a bypass (though I will install some kind of barrier between the hot half of the engine and the door cylinders and their tubing on the bottom of the fuse) and I'm not using the Y/A split pipe which the instructions are also built around. The Tam pipe uses a different kind of tab in the front, and doesn't include any mounting apparatus in the back, so I'll have to fabricate some other way to mount the aft end of the pipe. More later on that.
I'm working out the engine installation options. The instructions were built around a Jetcat P-180 and Y/A bypass. I'm not using a bypass (though I will install some kind of barrier between the hot half of the engine and the door cylinders and their tubing on the bottom of the fuse) and I'm not using the Y/A split pipe which the instructions are also built around. The Tam pipe uses a different kind of tab in the front, and doesn't include any mounting apparatus in the back, so I'll have to fabricate some other way to mount the aft end of the pipe. More later on that.
02-12-2017, 10:03 AM
#104
Thread Starter
02-12-2017, 10:07 AM
#105
Thread Starter
Well,
We're officially sanded and ready to fiberglass! Block sanded down to 320, then used flexible foam pad sander for the radiused leading edges so everything is nice and round. Will have the first side of each of the surfaces glassed by tonight.
We're officially sanded and ready to fiberglass! Block sanded down to 320, then used flexible foam pad sander for the radiused leading edges so everything is nice and round. Will have the first side of each of the surfaces glassed by tonight.
02-12-2017, 08:15 PM
#107
Thread Starter
Howdy,
I would've kept going, but I found out Al Jarreau died today. That took the building-wind out of my sails so I'm gonna grab a nice bottle of Merlot and go listen to some nice tunes by one of the good ones.
I would've kept going, but I found out Al Jarreau died today. That took the building-wind out of my sails so I'm gonna grab a nice bottle of Merlot and go listen to some nice tunes by one of the good ones.
Last edited by Shaun Evans; 03-28-2018 at 03:36 PM.
02-13-2017, 05:28 AM
#110
Thread Starter
I guess everyone has their own way, but with offset door hinges like these, I really only worry about the part of the hinge that goes to the fuselage. I see guys trying to get both parts flush to the fuse and door, but that doesn't seem to really work. Anyway, the further away the pivot of the hinge is from the hinge-line of the door, the less likely the door is to bind since it's swinging a wider arc the further from the pivot point. With the door taped in the closed position and the fuse half of the hinge attached, I attach the door side wherever it lands (and not try to get it flush, etc.) If when I untape it and try to open it, I get binding, I might adjust the location of the fuse side accordingly, or I might trim the arm of the hinge to clear the door opening. Having the right kind of hinges helps, too!
02-13-2017, 06:40 AM
#112
Thread Starter
Tom,
You're sure correct.
I've always thought the worst flying Y/A plane was the A-4 and I LOVED flying all of mine. This hornet looks like a prom queen and flies like a trainer. What a shame, indeed...
02-13-2017, 02:46 PM
#113
Hi,
I guess everyone has their own way, but with offset door hinges like these, I really only worry about the part of the hinge that goes to the fuselage. I see guys trying to get both parts flush to the fuse and door, but that doesn't seem to really work. Anyway, the further away the pivot of the hinge is from the hinge-line of the door, the less likely the door is to bind since it's swinging a wider arc the further from the pivot point. With the door taped in the closed position and the fuse half of the hinge attached, I attach the door side wherever it lands (and not try to get it flush, etc.) If when I untape it and try to open it, I get binding, I might adjust the location of the fuse side accordingly, or I might trim the arm of the hinge to clear the door opening. Having the right kind of hinges helps, too!
I guess everyone has their own way, but with offset door hinges like these, I really only worry about the part of the hinge that goes to the fuselage. I see guys trying to get both parts flush to the fuse and door, but that doesn't seem to really work. Anyway, the further away the pivot of the hinge is from the hinge-line of the door, the less likely the door is to bind since it's swinging a wider arc the further from the pivot point. With the door taped in the closed position and the fuse half of the hinge attached, I attach the door side wherever it lands (and not try to get it flush, etc.) If when I untape it and try to open it, I get binding, I might adjust the location of the fuse side accordingly, or I might trim the arm of the hinge to clear the door opening. Having the right kind of hinges helps, too!
I appreciate your help.. What Door Hinges do you recommend?
02-13-2017, 05:05 PM
#114
Thread Starter
Hi,
Before they went out of business, I'd have said Y/A. There are lots of clones of that offset hinge out there now, but I like these because they're very easy to glue to your door/fuse. They come with poly-ply screws and they're predrilled for the screws, too. They seem to have the right amount of offset. My #2 choice was BV's.
On this bird, one of the things you needed to do with the door hinges is use a wire as an 'axle' for the hinges since there are so many complex curves in the gear door area. Otherwise your hinges would be trying to swing on different arc-planes and binding/fighting each other.
Before they went out of business, I'd have said Y/A. There are lots of clones of that offset hinge out there now, but I like these because they're very easy to glue to your door/fuse. They come with poly-ply screws and they're predrilled for the screws, too. They seem to have the right amount of offset. My #2 choice was BV's.
On this bird, one of the things you needed to do with the door hinges is use a wire as an 'axle' for the hinges since there are so many complex curves in the gear door area. Otherwise your hinges would be trying to swing on different arc-planes and binding/fighting each other.
Last edited by Shaun Evans; 03-28-2018 at 03:37 PM.
02-14-2017, 07:25 PM
#115
Thread Starter
Hi,
So everything is glassed and all of the gear doors are hinged now. Tomorrow, I start the arduous task of sanding out the glass/resin on the wings, tails and control surfaces. 220 wet, then 400 wet.
So everything is glassed and all of the gear doors are hinged now. Tomorrow, I start the arduous task of sanding out the glass/resin on the wings, tails and control surfaces. 220 wet, then 400 wet.
Last edited by Shaun Evans; 02-14-2017 at 07:31 PM.
02-19-2017, 04:05 PM
#117
Thread Starter
Hello,
I had an interesting time with one of the main gear doors. The geometry margin was so small that either it didn't close quite flush OR it didn't open enough for the wheel to clear when it went by. Solved it, though. Another geometry consideration is making sure the outer main doors don't open enough to hit the wheel when the plane bottoms out on the springs.
These Y/A gear are nice. I remember doing a bunch of builds on another brand (which shall remain nameless) where the gear almost never retracted and deployed reliably in the same flight. Even on the bench, it would take 3/32" I.D. tubing, huge tanks and 120 PSI to get the gear to work. Between that and everything leaking, most flights (even by the factory reps) had at least one gear leg hanging down. With these, this air line is maybe 1.5mm I.D., lots of line, relatively heavy struts, and they'll work with all three units and 9 doors on 40 PSI
That's after holding 80 pounds overnight without losing pressure any at all.
https://youtu.be/i5urMTwIQOc
I had an interesting time with one of the main gear doors. The geometry margin was so small that either it didn't close quite flush OR it didn't open enough for the wheel to clear when it went by. Solved it, though. Another geometry consideration is making sure the outer main doors don't open enough to hit the wheel when the plane bottoms out on the springs.
These Y/A gear are nice. I remember doing a bunch of builds on another brand (which shall remain nameless) where the gear almost never retracted and deployed reliably in the same flight. Even on the bench, it would take 3/32" I.D. tubing, huge tanks and 120 PSI to get the gear to work. Between that and everything leaking, most flights (even by the factory reps) had at least one gear leg hanging down. With these, this air line is maybe 1.5mm I.D., lots of line, relatively heavy struts, and they'll work with all three units and 9 doors on 40 PSI
That's after holding 80 pounds overnight without losing pressure any at all.
https://youtu.be/i5urMTwIQOc
