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Upper Cowl hinge pins hard to move

WingedFrog

WingedFrog

Well Known Member
After riveting the hinges on the cowls and reinstalling the lower and upper cowls, I had difficulties reinsterting the F-1201J and F-1201K hinge pins on the top of the upper cowl. There is lots of friction and the last few inches are tough to insert. I did not use any lubricant anticipating painting in the near future. Has anyone suggestions to improve this situation?
 
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WingedFrog said:
After riveting the hinges on the cowls and reinstalling the lower and upper cowls, I had difficulties reinsterting the F-1201J and F-1201K hinge pins on the top of the upper cowl. There is lots of friction and the last few inches are tough to insert. I did not use any lubricant anticipating painting in the near future. Has anyone suggestions to improve this situation?
Click to expand...

Use a bit of candle wax on the pin(s). Just rub the pin in a big piece of wax or a candle.
 
That's normal

on almost all Van's airplanes, not just the -12. For the first few weeks I had to tap the end of the hinge pin with a wooden block to get it seated. I remember my hangar mate, who'd built a -7 before I stated the -12 having the same problem). The steel pin will wear away the aluminum hinge; after two years mine slide in easily. Using Boelube PASTE (not liquid, available from Aircraft Spruce)) on the pins will help a lot. Wipe the pins off each time they're removed--they will be blacl-- and apply fressh Boelube each time they're inserted.

Wayne 120241/143WM
 
Hinge Pins

I found that installing the top cowl pins before installing the side pins helps.

Gary Eldridge
 
You make the call!

I would use some 400 grit sand paper to sand the pins, then sand with a scotch brite pad. Then bend the pins in an arc to match the curvature of the glair shield where the inner hinge is located. Then use boelube. This sanding method will reduce the diameter of the pin a very small amount and polish it as well. When inserting the pin rotate the curve 90 degrees to the curve for the first few inches of the hinge then rotate the pin to Match the curve. Just another technique to use. All the other suggestions are good to. So as the builder you make the call!;) Oh yeah sand a dull point on the end of the pin to help it center on each inner hinge piece as it goes through the hinge.
 
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Forget to cowl, I can't get the pin in or out on the toolbox I built! It doesn't really matter, when the pin is in, I can barely open the box anyway. I was thinking of leaving the pin out and getting another snap latch and using it instead.

I did get better - on the elevator, it works great!
 
Tight Cowl Hinge Pins

Built an RV9A and an RV6A and both have cowl hinge pins. On the first one we had similar tight fit problems as noted. After considering the options we took a length of cowl hinge pin and ground the end square. We then took and hammered the ends on both sides to slightly flatten them. This increased the diameter a small amount. We then chucked the the hinge pin in a drill and ran it thru the hinges. Essentially you have a long reamer. A few passes with additional hammering yielded a good snug fit.
 
Sanding or using smaller pins is not a good idea. Vibration will make everything a lot looser in a few hours. First, be sure the ends of the pins are ground to a point. I use A TOILET BOWL WAX RING (soft beeswax) to lubricate the pin. Slides in like, well, easily.
Easy to apply and inexpensive.
 
Glad I started this Thread!

An abondance of advice tells me that this thread will prove useful for many. I researched before posting but could not find anything close to what's here. Now what in the world am I going to chose among this profusion of advice?:D
Just kidding, of course, as John/Jetguy rightly said, I'm the builder, it's my call, no one else's!
Thank you all!
 
After flight and engine warming of the cowls and resulting relaxation of the resins, the pins will slide in and out with much less resistance.

doug
 
WingedFrog said:
An abondance of advice tells me that this thread will prove useful for many. I researched before posting but could not find anything close to what's here. Now what in the world am I going to chose among this profusion of advice?:D
Just kidding, of course, as John/Jetguy rightly said, I'm the builder, it's my call, no one else's!
Thank you all!
Click to expand...

I just open the two camlocks on either side and in a jiffy, have opened the cowl to check the oil and look around inside for any problems.... Just like on the Cherokee.

Wait a minute - wake up, Bob - you big goofy - you've been day-dreaming again....

Bob Bogash
N737G
 
All of the above!

On my second try, I used some of the tips above and I had good results:
- Shaped the pins to comply with curve of the cowl
- Put a light coat of wax on the pin and passed the pin through each half hinge first
Only problem, with shaped pins the end of the pins that is bent to fit under the cover gives a strong recoil which bents the cover out of shape (I realized later that I should have shaped the pins with the bent end in the same plane rather than at a 90 deg angle)

correction: my mistake, it's just the opposite, bend the pin so that the square end is at a 90 deg angle with the bent and be careful to put the bend on the right side.
 
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Pull side pins and screw first

Try removing the front cowl screws, then the side pins then the upper cowl pins. Reverse when cowling back up.

Works for me anyway.

Gary Eldridge
 
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