Jon Clements
Well Known Member
I have seen heaps of RV's on the forums (and in the flesh) with the horizontal hinge pins fitted as per vans instructions (or similar). The pin sticks out the front of the cowl with a screw fixing or a cover plate of some description and in my opinion it's something that can be improved without too much trouble.
The standard fitment seems to meet the keep it simple rule but when it comes to design/drag and aesthetic considerations it falls well short of the mark.
I bashed my head over this one for a long time and then the following solution came to mind when i had my top cowl installed with the Skybolt camlocks loose....
If you are opposed to Camlocks you can disregard this solution. If you are sitting on the fence in relation to whether or not you will install camlocks, this might convince you.
I originally ordered a full Camlock kit (primarily to make cowl removal/engine access as easy as possible) but after much consideration I decided that Camlocks to the full firewall with hinge to the horizontal joints would look better from an aesthetic point of view.
To cut a long story short (it involves many hours staring at the cowl) I eventually realised that when the camlocks are loose on the side of the cowls (top and bottom) you can quite easily pull the cowl outwards from the fuse and gain access to the horizontal hinge from the rear of the cowl.
I had previously considered running a hinge back into the cockpit through the firewall or alternatively through the firewall and then up and out through the NACA vent but neither option appealed, and both had obvious cons.
What I came up with follows in the photos below:
I filed out a small recess from the bottom cowl to the horizontal joint (approx 2 inches) and then down the vertical joint (approx 3/4 inch. I then put a small joggle in the hinge pin (to clear the 1 3/4 inch aluminum tab that the camlocks are fitted to) and added a 90 degree downturn to the end.
The down turn allows you a firm grip to the pin when feeding it into the hinge from the rear (you insert the pin with the downturn pointing out perpendicular from the fuselage) and then when the pin locates fully you rotate it down 90 degrees at which point the joggle locates itself over the camlock tab behind. The pin sits neatly in the recess and the camlocks are then twisted into the lock position which flushly locates the pin in the space between the fuselage skin and the cowl.
To remove you simply unlock the side camlocks, pull the cowl outwards fractionally, rotate the pin up 90 degrees and then remove....simple.
I am really happy with how it works functionally - it is neat, simple and low drag.........and the cowl nose looks the way it should!!!
Oh yeah.....the downside - it costs approximately $200USD more because you need camlocks.....
I am hoping this thread will result in other builders posting feedback and images of a range of alternative ways of fitting the cowl hinge pins.......there is more than one way to skin a cat...
The standard fitment seems to meet the keep it simple rule but when it comes to design/drag and aesthetic considerations it falls well short of the mark.
I bashed my head over this one for a long time and then the following solution came to mind when i had my top cowl installed with the Skybolt camlocks loose....
If you are opposed to Camlocks you can disregard this solution. If you are sitting on the fence in relation to whether or not you will install camlocks, this might convince you.
I originally ordered a full Camlock kit (primarily to make cowl removal/engine access as easy as possible) but after much consideration I decided that Camlocks to the full firewall with hinge to the horizontal joints would look better from an aesthetic point of view.
To cut a long story short (it involves many hours staring at the cowl) I eventually realised that when the camlocks are loose on the side of the cowls (top and bottom) you can quite easily pull the cowl outwards from the fuse and gain access to the horizontal hinge from the rear of the cowl.
I had previously considered running a hinge back into the cockpit through the firewall or alternatively through the firewall and then up and out through the NACA vent but neither option appealed, and both had obvious cons.
What I came up with follows in the photos below:
I filed out a small recess from the bottom cowl to the horizontal joint (approx 2 inches) and then down the vertical joint (approx 3/4 inch. I then put a small joggle in the hinge pin (to clear the 1 3/4 inch aluminum tab that the camlocks are fitted to) and added a 90 degree downturn to the end.
The down turn allows you a firm grip to the pin when feeding it into the hinge from the rear (you insert the pin with the downturn pointing out perpendicular from the fuselage) and then when the pin locates fully you rotate it down 90 degrees at which point the joggle locates itself over the camlock tab behind. The pin sits neatly in the recess and the camlocks are then twisted into the lock position which flushly locates the pin in the space between the fuselage skin and the cowl.
To remove you simply unlock the side camlocks, pull the cowl outwards fractionally, rotate the pin up 90 degrees and then remove....simple.
I am really happy with how it works functionally - it is neat, simple and low drag.........and the cowl nose looks the way it should!!!
Oh yeah.....the downside - it costs approximately $200USD more because you need camlocks.....
I am hoping this thread will result in other builders posting feedback and images of a range of alternative ways of fitting the cowl hinge pins.......there is more than one way to skin a cat...
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