Rivet spacing

I'm at the point of drilling the horizontal stab skin to to the skeleton but I have a dilemma. Van's notes to alter the rivet spacing on the rear spar as needed to avoid putting a rivet in the area of the hinge brackets thereby making it difficult or impossible to buck the shop head.

I've laid out the spacing using the nominal 1.25" called out on the plans starting at the tip rib and sure enough a rivet lands exactly between the two hinge plates. Now my dilemma is: Is about 1/2" spacing between the brackets enough to allow a narrow bucking bar to fit in or is that all just too much hassle and just re-space them out? I may just be being picky but I hate the idea of uneven spacing and it worked out so well other than the one bloody rivet.

Here is the nominal spacing in blue with a proposed altered spacing in red at 1" (or so) apart. The vertical line shown is that of the mid rib centerline so I could start the new spacing there but that puts 3-4 rivets at 1" apart and I don't want it to look strange. Someone please push me into a decision, I sat and stared at this for way too long last night, sheesh!

HS Stab by jim_soutar, on Flickr

Putting a rivet in the middle of the two hinge angles is not really a big deal, just needs a skinny ended bucking bar.

Mark for that rivet and move away in both directions with your even spaced rivets. 1.25 inch is nominal, but a bit smaller spacing is OK if that looks nicer to you.

One of the most useful bucking bars I have is nothing more than a piece of 1/2inch plate about 8 inches long by 3 inches wide with a 1inch wide tange on one end. Gets in a lot of places. It also has a few holes drilled in it to put a squeezer set in it.

Bob burns
N82RB
Rv-4

Interesting that the rod end is attached to a single sided mount.

Is this something just done in the early designs or is it just the smaller/lighter airframes??

My 10 uses steel instead of extruded alum, and there is a pair of mount tabs.

Mike, That's just a set up jig for alignment purposes.
OP, I always plan my spacing in this scenario to place the rivet dead center as in your case. As the others said, you'll find a way to buck or squeeze......and smile after the fact .

Mike S said:

Interesting that the rod end is attached to a single sided mount.

Is this something just done in the early designs or is it just the smaller/lighter airframes??

My 10 uses steel instead of extruded alum, and there is a pair of mount tabs.

Click to expand...

Thanks Rick, that explains the screws mounting it also.

You bet Mike, the 'newer' kits have come a long way.....folks don't know what they are missing !

Mike S said:

Thanks Rick, that explains the screws mounting it also.

Click to expand...

Thanks all, I spent some more time with spacing today and I found a neat thing. 1-1/8" spacing lines up with 1-1/4" spacing every 11-1/4". I started at the root rib with 1-1/8" and it worked out nicely with the middle hinge brackets, then I switched to 1-1/4" spacing half way out to the tip rib which worked out nicely with the outer hinge brackets. Incidentally, 22-1/2" is almost exactly in the middle of the skin at the trailing edge

This accomplished two things, all rivets avoid the hinge brackets and the spacing is very uniform. It's almost impossible to see 1/8" difference in the spacing. I just wouldn't have been happy with a few rivets 1/2" or 3/4" apart.

Here's a neat trick to make measuring out the spacing a little easier. Yes I have a rivet fan but it's of little help in determining best spacing. I used two different color markers to mark my ruler off at the different spacings. Makes visualizing much easier.

Untitled by jim_soutar, on Flickr

You could also use a blind rivet if you can't buck it. Fill the hole in the rivet before paint and no one will know