How to build stand-offs?
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How to build stand-offs?
I'm trying to reduce the nose weight on an 50cc Edge with a G-62 up front. Right now I'm using a greatly reduced piece of 3/4" plywoood and a stack of three steel fender washers per bolt to get the 7/8" spacing I need. What can I use to make lightweight stand-offs that will not press into the firewall, and will seat nice and flat on the back of the engine?
Thanks!
Forrest
Thanks!
Forrest
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RE: How to build stand-offs?
Do what BB does but sand the dowels flat to evanly contact the engine after they are positioned and CA'd to the fire wall. Ca'ing them to the firewall will help to keep the firewall from crushing. Get or make some aluminum washers (1" hole saw) that covers the end of the dowel. Then sell the 62 and buy a light engine.
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RE: How to build stand-offs?
You can go for the flash and style, be lazy, like to spend money, and buy aluminum standoffs that usually require that you add washers or spacers to get the length correct, or, you can make them out of wood, be just as light or lighter, reduce vibration levels, have the exact and correct length every time, and be cost free. Hardwoods and drilling straight holes are the only requirements.
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RE: How to build stand-offs?
ORIGINAL: 72
BB- Do the bolts go all the way through he dowels or are there bolts from both ends into the dowel?
BB- Do the bolts go all the way through he dowels or are there bolts from both ends into the dowel?
http://www.microfasteners.com/
#11
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RE: How to build stand-offs?
Don’t laugh I didn’t build the airplane. The construction was better than my building skills but I did mount the engine and equipment.
Postmortem revealed the firewall had been out sometime in the past. In addition a slightly out of balance prop had been run for 5 to 10 flights (by me unfortunately). Best guess is that the out of balance prop destroyed the firewall epoxy joints, which may not have been the best to start with.
After the 6 pound engine parted company with the airframe flight control was still available. At 6 pounds out of balance I was unable to deliberately put the airplane into the ground in a safe location and it floated merrily along its way over a neighbor’s house and cars and finally landed in his front yard. An embarrassing event, which could have been very expensive.
Bill
Postmortem revealed the firewall had been out sometime in the past. In addition a slightly out of balance prop had been run for 5 to 10 flights (by me unfortunately). Best guess is that the out of balance prop destroyed the firewall epoxy joints, which may not have been the best to start with.
After the 6 pound engine parted company with the airframe flight control was still available. At 6 pounds out of balance I was unable to deliberately put the airplane into the ground in a safe location and it floated merrily along its way over a neighbor’s house and cars and finally landed in his front yard. An embarrassing event, which could have been very expensive.
Bill
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RE: How to build stand-offs?
So, hardwood seems priced right, after doing some online shopping and comparing. I only need 3/4" of wood plus a 1/8" aluminum washer. So, any reason I can't use a 1" holesaw on an oak board? Or use plywood for that matter?
Even just switching to aluminum washers will save a couple of ounces I suppose.
By the way "altavillian", the G-62 is the lightest, most reliable engine I've ever run - for free.
ff
Even just switching to aluminum washers will save a couple of ounces I suppose.
By the way "altavillian", the G-62 is the lightest, most reliable engine I've ever run - for free.
ff
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RE: How to build stand-offs?
ORIGINAL: TheFoxes
So, hardwood seems priced right, after doing some online shopping and comparing. I only need 3/4" of wood plus a 1/8" aluminum washer. So, any reason I can't use a 1" holesaw on an oak board? Or use plywood for that matter?
So, hardwood seems priced right, after doing some online shopping and comparing. I only need 3/4" of wood plus a 1/8" aluminum washer. So, any reason I can't use a 1" holesaw on an oak board? Or use plywood for that matter?
#16
RE: How to build stand-offs?
I've used a 3/4" and a 1" hole saw to drill out aircraft ply donuts. The hole saw just happens to have a 1/4" pilot bit.
I'll stack up 3 layers of 1/4" ply and drill through them before emptying the hole saw out of the collected donuts. Then drill another stack. Continue until you have enough 1/4" donuts to stack up. Sand smooth and knock the burrs off.
I epoxy them together with a slow setting glue. Run a nylon 1/4--20 bolt covered in wax paper through the middle for alignment and clamp it overnight. Wipe off excess epoxy while it's still soft.
The longest standoffs I ever made like this were 1". I'm not sure if they would still work as well if you went up to say, 1.5" or 2".
I'll stack up 3 layers of 1/4" ply and drill through them before emptying the hole saw out of the collected donuts. Then drill another stack. Continue until you have enough 1/4" donuts to stack up. Sand smooth and knock the burrs off.
I epoxy them together with a slow setting glue. Run a nylon 1/4--20 bolt covered in wax paper through the middle for alignment and clamp it overnight. Wipe off excess epoxy while it's still soft.
The longest standoffs I ever made like this were 1". I'm not sure if they would still work as well if you went up to say, 1.5" or 2".
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RE: How to build stand-offs?
FF; hard to beat free. I recomend dowels over plywood or cutting circles out of hard wood. Hardwood dowels are usualy made from maple. Becase it's the hardest wood. They will not compress enough to notice. Especially on the ends. You will see how hard they are when you start to sand them flat. Put a pencil mark on the ends and it takes 10 minutes to get it off. Blind nuts come in different lengths through the threaded area. Get the longest you can. Do not locktite the bolts into the blind nut. Just check them and re-tighten them after the first 4 then 6 then 12 etc. flights. Most of the loosening you will have will be the blind nut stretching and seating in the firewall.
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RE: How to build stand-offs?
I like to jam a Nylock nut behind the blind nut. Easy to tighten up without having to re-apply locktite, and it "firms up" the back of the blind nut. Maple it is! Thanks!
ff
ff
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RE: How to build stand-offs?
Super; I was going to say put a lock nut there if you want to be more secure. The blind nut will spin before letting go of the bolt if you locktight them.