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Converting Cowl attachment to Skybolt (or similar)

Graham

Active Member
Hi,

I am close to finishing my RV6 (after 20+ years) and am finding the Top Cowl Piano hinges very frustrating to install/remove. So, I am considering changing to 1/4 turn fasteners.

Has anybody had actual experience of doing this conversion? I imagine that the worst aspect would be removal of the existing hinge halves, which are rivetted & glued to the cowls. Lots of grinding required...

In the meantime, I shall try the advice for improving the fit that is available on this great website.

All feedback highly appreciated.
Thanks
Graham (in New Zealand).
 
Stick with them.
Lube them. Give them some pre bend.
Grind and polish the tip to a bullet point.
They do wear in with use. Don’t make a decision before 100h and a dozen or so remove/refits.
I can have my top cowl off in a matter of seconds with pins.
Plus I like the clean look but I accept that’s subjective.
 
If you do convert to 1/4 turn.

One challenge to be careful of is the location of flange that holds the female component. Getting exactly right for good height match up when tightend. Not pushing Skybolt at all, just a reminder their claim to fame is the adjustable feature to make height matchup easy.

Also don’forget the need to stiffen the cowl to avoid ballooning as discussed here at length.
 
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I've just made this change... It is quite a bit of work to fit the 1/4 turns but it does make the cowling removal and installation much easier. I have retained the hinge on the vertical side of the fuselage and between the cowl halves. I used the triangular shaped brackets supplied by Skybolt but would not do so again. Use some 0.063", shim from the firewall to match the thickness of the cowl. Clamp the cowl to airframe in the required position and drill holes for fasteners to ensure holes match. Drill as large as possible as drilling out to final size always carries a risk the holes will wander. Underneath put the inboard fastener as far inboard as reasonably possible and extend the aluminium further toward the centre otherwise it will crack.
 
I have done the conversion on 2 flying RV-6's.........on new James cowlings.
Was not happy with hinges.
It is a lot of work, and a few hundred dollars, but once done you will be happy with it.
 
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