How much downhill do I need?

coloradobluesky

coloradobluesky

En-Route
Gone West
Joined
Mar 19, 2014
Messages
3,621
Location
Colorado
Display Name
Display name:
coloradobluesky
I have a winch to pull my Husky into my hangar. But I have to pull it out (with a yoke I fashioned). I want to build a platform with a ramp going up to it and use the winch to pull it up the ramp. Then it goes to a level platform. Should I put my 3/4" plywood on 1x2s (3/4" high) or 2x4s (1 1/2" high). The ramp is 100" long so 1" up is a 1% slope. I want it to make it out the door threshold which is level for a couple of feet, then it will coast on out to the ramp. Should be pretty slick. Pull the chocks and give the plane a shove and watch it coast on out. How cool would that be?
 
First you must calculate the "drag" of the tires using the coefficient of friction of the boards and tires (rolling since you give it a push) and the weight. That will determine your speed or momentum at the end of the ramp then you'll need the new coefficient for the tarmac to determine if you have enough momentum to get it out as far as you want. Of course, it will have to be done for wet and dry and you'll need to know the initial speed from the push but all that can be measured and put in the calculations and then just iterate until you have what you want.

OR

build it big and then just stop the lane when it gets to where you want it.
 
car_tire_pressure_rolling_resistance.png
 
Taxi it out. Once knew a guy who did that regularly. No loose junk in that hangar at all.
 
How strong are you? I am not that strong and can move my plane on the flat by myself...in the grass on hard ground (2000 lbs with a tailwheel). I'd suggest you move it around a bit experimenting and then you'll know. Also I have one of these ramps for my tailwheel, plywood for the mains. http://www.pviramps.com/products/product-details/id/1
 
luvflyin said:
Once? Sounds like there is a story here. Just what made him not try it twice?
Click to expand...
A Navion tends to compress the nose strut when the engine starts. Not a lot, but enough to raise the tail quite a bit - enough that the rotating beacon was higher than the hangar door opening.
 
Right now I'm leaning toward putting the platform on 2 x 4s laid flat so I get 2 1/4" in 96". I could go with putting it on 1 x 2's laid flat which would give me 1 1/2" in 96". That might be enough, don't really know.

But, what I need to do if go out and find a place on the ramp where I barely coast and put a level on it and see how steep it is. That should do it.
 
You must log in or register to reply here.
Back
Top