Kristoffon
Well-Known Member
I'm building an Osprey-II amphibian and one thing that I'd really like to have is a reversing propeller to ease maneuvering on the water around tight spots. If I simply wanted a variable pitch I'd go with the Ivo.
However I figure I can replicate the design from here which seems simple enough: a push rod goes through the propeller axis and directly actuates the blade. I figure 90 degrees pitch change are doable which would satisfy the reversing requirement, I think.
Some drawings of a similar system can be found here..
I will be using a 2 spur reduction drive designed by myself so the hollow axis is easy to do and the offset means the engine can be maneuvered around.
Being purely mechanical it's simpler than a hydraulic type and I feel I can do it competently. I could do it with Warp Drive blades. Testing is doable on a ground stand with mock blades at higher speeds and loads to validate the design and uncover any flaws. As long as a failure during testing doesn't damage the engine or redrive I can build 100 hubs like that for what a commercial reversing propeller would cost me.
My motivation is that I already own a spot in an yacht club I could use as the aircraft's home during holidays. However access is through a somewhat crowded canal and I can't really see myself navigating it safely without a form of brake/reverse. I don't want to come across as just making it for novelty value.
Any opinions?
However I figure I can replicate the design from here which seems simple enough: a push rod goes through the propeller axis and directly actuates the blade. I figure 90 degrees pitch change are doable which would satisfy the reversing requirement, I think.
Some drawings of a similar system can be found here..
I will be using a 2 spur reduction drive designed by myself so the hollow axis is easy to do and the offset means the engine can be maneuvered around.
Being purely mechanical it's simpler than a hydraulic type and I feel I can do it competently. I could do it with Warp Drive blades. Testing is doable on a ground stand with mock blades at higher speeds and loads to validate the design and uncover any flaws. As long as a failure during testing doesn't damage the engine or redrive I can build 100 hubs like that for what a commercial reversing propeller would cost me.
My motivation is that I already own a spot in an yacht club I could use as the aircraft's home during holidays. However access is through a somewhat crowded canal and I can't really see myself navigating it safely without a form of brake/reverse. I don't want to come across as just making it for novelty value.
Any opinions?
