C-621 Canopy release link

[bruceh]

I started fabricating the canopy release hinge blocks and release pins. The finish kit supplies a steel tube ST4130-035X3/8X5 3/4 for C-621. The plans on DWG 47 show a length of 5 19/64" between the centers of the two holes for the pins, and those are 1/4" from the ends of the tubing. That adds up to 3/64" more than the 5 3/4" that Van's provides. The other part of the release linkage is another tube that has to be cut down a bit from what is shipped.

What is the story on the missing 3/64", or is that a non-issue? I get worried when the plans start getting down to the 1/64" of an inch in precision. I'm not that precise!

 

[Robert M]

I just finished drilling and cutting the same parts. Both of the pieces that I got with the kit were longer than was needed. Contact Van's, they should send you another piece. If not, the same stuff is pretty cheap at Aircraft Spruce.

 

[mquam99]

another tube

I think there may be two of those tubes in the finish kit.. I actually cut down the wrong one and had to order extras..

I am not in front of my plans or build right now. Just writing from memory

 

[bruceh]

The tubes match the inventory list

I got two steel tubes in the kit. One is 5 3/4" (3/64" too short) and the other is 9" (needs to be cut down about 1/2").
I'm just wondering why Van's would specify the one at 5 3/4" if that is shorter than the plans show.

 

[704CH]

RV-7 same issue

Hey Bruce, I just finished that process as well on my finish kit. I received two tubes, the short one I couldn't cut at all and was even a couple 32nd's short to get the 1/4 inch centers of the holes from the ends. I split the difference and it turned out well. In fact about 1/32 to long, so I would recommend looking and measuring directly yourself, but if you put the 1/4 center from each end on the short tube it should work out pretty much exact..

I ended up having to cut about a 1/2 inch off the longer tube..

Thanks

www.704ch.com

 

[Vlad]

Can not help you with the parts count but I can tell you how convenient the quick release is. I wish I installed a modified mechanism. It's so difficult to get to those pins without help from outside. Plain nightmare especially if you need to do it several times. Good feature that canopy release thing. I may have some parts too.

 

[Loman]

I just made do with what I had

Bruce,

This exact thing happened to me just two weeks back. You are correct that the material supplied is too short.

I decided it wasn't structural so I tightened up the spacing by a 64th or so (who can tell once you get down to 64ths) at each end and that leaves me with marginally less edge distance at the ends plus that pin is a 64th or so short of it's intended position. My hinge axel pins were already cut at that point but if yours are not, maybe you could cut the RHS ONE a smidgeon (scientific term) longer. Otherwise keep the 1/4 at each end of the pushrods and add all three smidgeons to the length of the hinge pin.

 

[rapid_ascent]

Bruce,

It sounds like you could make due from what the others have said, but I don't look at it that way. I think you should call Vans and have them send you another part. This is the only way that they will get feedback and they can use that information for QC purposes. If everyone does that when they find a problem hopefully these types of things will get fixed for future builders.

Just my two cents.