jimboflying
MEMBER
jimbo, On the surface this sounds like a good idea. However, be absolutely certain the stick will not fail from forces you have not imagined. IF that stick should buckle while in flight, will you be able to control your airplane by reaching to the back seat to use the other stick? Chances are it will not fail, but are you certain? Do you want to be the one who finds out when? The highest load on that stick will be at the location where it plugs into the socket just above the pivot.I decided to try to decrease the weight of control sticks for my experimental PA14. The previous metal green one weighed in at exactly 1 pound. The black carbon fiber one weighed 4 ounces and seems plenty stiff.
I'll not attempt to supply you with that list, It may not be all inclusive.skyawagon8a, can you provide a list of forces acting on the stick and perhaps their magnitude that we should consider when altering a stick? I know during my build I'd like to go with a more ergonomic stick like I used in the military. Having an idea of potential forces and their magnitudes would be helpful when engineering a new stick.
True, but no excuse for taking a risk with primary controls.If a stick failed in a -14 there's a spare about 18" to the right.
If a stick failed in a -14 there's a spare about 18" to the right.
All -18 front sticks should go under the panel. Originally there is a folding gust lock which grabs the top of the stick under the panel. The back stick does depend on how far back the seat moves and how big the back seat belly is.Its a Javron and I had to cut it down to get full movement therefore it travels under the panel and hits the seat base. ...I often wonder how normal cub pilots get full deflection when their stick hits the panel. Is this all because I have increased deflection of my horizontal stab? Does any one else suffer from this affliction?
All -18 front sticks should go under the panel. Originally there is a folding gust lock which grabs the top of the stick under the panel. The back stick does depend on how far back the seat moves and how big the back seat belly is.
Banging knuckles is partially correct. Another answer is, it depends. It depends on the shape and number of radios. The gust lock is U shaped and will swing around and under some installations.That's what I always thought, but this triggers a side-question. What do people do who hang radios under the panel?
True but that's the way it was done for years before solid state was invented.One of the worst places to mount a radio in a Cub type aircraft. In the way of the stick, probably in the way of the gust lock, and hard to read and manipulate the radio.
Web
Bang their knuckles.
Web
As my last career was in the boat business ...
Or change their sticks.
As my last career was in the boat business I knew a fiberglass guy that did a lot of carbon fiber. He was a rag bagger and like most of us enjoyed creating new improved parts for his sailboat. He swung in One day with the most beautiful tiller handle I’ve ever seen. It was light enough to hold with two fingers, had a S-curve in it that was a work of art and if you stuck the end of it in a slot the two of us could do chin-ups on the other end all day long with zero flex.
As I can’t exert 350 lbs of force on the end of a 18” stick let alone a 5 foot tiller handle, I’d trust a well laid up carbon fiber stick any day.
And like the knowledge that roams in these halls, he didn’t engineer it on a computer. He reached into his bag of experience like Steve Pierce does, and simply built it knowing how fiberglass mat, weave, resin and strength works.
Sure, be smart about it. But don’t shy away from the possibilities.
Transmitted from my FlightPhone on fingers...
CAR 3 has design stick forces listed. They're greater than I would have guessed, and far greater than I experience in my -12. However, that's the design standard.skyawagon8a, can you provide a list of forces acting on the stick and perhaps their magnitude that we should consider when altering a stick? I know during my build I'd like to go with a more ergonomic stick like I used in the military. Having an idea of potential forces and their magnitudes would be helpful when engineering a new stick.
That's quite interesting. I was wondering about steel control sticks needing gussets or something to stop the crumpling. That was before this thread came up.The sticks were made on a special aluminum mandrel with a custom layup with unidirectional fiber orientation lengthwise. Calculations by an aerospace professor showed that the strength was comparable to .065 Aluminum. Thin Steel .035 has a different failure mechanism with localized crumpling. The calculations show that conservatively the carbon fiber structure sticks should withstand 170 pounds of force.