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tvlawyer

Active Member
I put many hours into workin gon my tail this weekend and got to the point where I riveted the HS-411 elevator brackets around the Y-146 bearing. Using AN470 4-6 rivets, all were textbook except one looked rather short. I drilled it out and made sure to clamp the HS-411's tightly together before bucking another rivet. It was again too short. I can't figure out why the others are OK and the one is short. After drilling out two bad rivets the hole is somewhat enlarged. Should I use a larger rivet in there?

BTW - I primed the rear spar and reinforcement bars with Sherwin-Williams GBP-988 (thanks Dan Checkoway for the recommendation) The GBP-988 is a pleasure to work with. Goes on evenly and parts are ready to handle in about 15 minutes or less.
 
Gauge

Hi Larry,
Sometimes, the wrong size rivet will find its way into the bag, so check them as you use them. Secondly, do you have a rivet gauge? Its a little device that you put against the rivet before you drive it to determine if it protrudes far enough.

Another trick is to make a simple gauge to see if you've driven the rivet enough: Since the finished rivet head should be 1.5 times the original diameter,, drill a 9/64" hole in a piece of scrap and a 3/16" hole on the opposite end. These are the finished diameters of the 3/32 and 1/8" rivets respectively. They should just fill the hole in the gauge if they're set correctly.

On your enlarged hole, unless it's really sloppy, use the same diameter rivet again,
Regards,
 
I bucked that rivet three times with the same result. It's too short and the shop head doesn't mushroom enough. The others turned out just fine. In fact, as measure with the little rivet gauge, they're damned near perfect. I can't figure out why I can't get this one rivet, in a circle of five (or is it six? I don't have it in fron of me.) to set properly.

The HS-411 is a small part, hard to buck. I think I'll wait until my pneumatic squeezer arrives this week and then try it again.

P.S., Pierre. Did I tell you I got a hangar at RYY? I had to buy the building and I will sublease it until it's time to put the wings on. But at least I found away around the 5+ year waiting list.
 
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This sounds similar to the problem I had with the HS-911 brackets. The rivet size specified is very close to being too short, but it works if everything is perfect. One of the holes on that part ended up getting a bit enlarged when I made multiple attempts, and I think this slightly enlarged hole made it impossible to get the height of the shop head right (they always ended up too short). I suspect it's because more of the rivet material gets squished out to fill the slightly enlarged hole.
 
Try a little longer rivet

Try a little longer rivet to allow more material to fill the hole. If the hole is too large, you will neet to use an oversized rivet.

This hinge is really not needed soon so you can move on until you get your squeezer. You will love that thing when you get it. Make sure to get an adjustable set holder because that is what makes a pneumatic squeezer really great.
 
Will work Sometimes

It will work sometimes. Not for a grossly oversize hole but for a slightly oversize hole it will work just fine. Pre squeezing a little usually stops it from bending over.
 
Don't always follow the directions! If a rivet looks to short before you buck it, it probably is. As you get further into it you will realize the rivets they call for don't always work. Primer will sometimes create a small enough thickness change that will force you to choose a larger rivet.
You might want to buy a rivet cutter and some long rivets. This will allow you to cut to a specific size.
Sometimes you have to go drink a beer and come back an hour later! When you come back, you will be well rested and that one rivet will take you two seconds to do it correctly.
Good Luck
 
Buy a bag of long rivets of each style and cut to fit

Even in military production aircraft drawings the notes allow for substitution of longer rivets to accommodate tolerance buildups etc. Pretty early in the process I bought a 1/4 lb of AN470AD4-10 rivets, AN326AD3-10 rivets and a rivet cutter from Aircraft Spruce to deal with short rivets. If the rivet looks too short ... it is too short. If it is too long it will clinch over and look horrible. You can generally squeeze a longer rivet satisfactorilly than you can drive and buck one. It doesn't take long and you should be able to judge what is right. I squeeze the rivets whenever possible but I use a mechanical (hand) squeezer from Avery that I bought in 1996. I believe it is important to develop as personal a relationship with the process as possible. It sounds like you know the theory and the general acceptance criteria but you are hung up on literal compliance with the drawing callouts. Sometimes the drawings are not correct for the application because of tolerance buildups or drawing error. I would take a rivet that extends through the material around 1.5 times the diameter of the rivet and squeeze it in place carefully and forget it if the installation produces a good looking rivet installation.

Bob Axsom
 
Here's a little trick you may want to try if you have a pneumatic squeezer; might be doable with a manual one. Works for 426 rivets, anyway; haven't tried it on 470's.

Take the next longer rivet. Mike it to check the length. Compare with the length of the specified rivet. You are going to shorten and fatten the longer rivet.

Put rivet set for a 470 rivet in the yoke opposite the ram. Adjust the squeezer to close to a length about halfway between the two (you do have an adjustable ram, don't you?). Set the rivet in the squeezer (hold the thing upside down with the rivet on the end opposite the ram to keep the rivet from tipping). Carefully squeeze the rivet. Now you have a rivet that is a little shorter and fatter, so it will cover the longer distance needed and will fill the hole better.
 
how much of a beating can the HS-411 take?

Now that I'm done with the practice kits and have moved on to the real deal the 4th rivet I set needed to be drilled out. I too think the rivet call-out in the plans is too short... unless somehow the primer on my VA-146 added another half mm :)

I had to energetically beat on the 411 with a hammer and punch to get the rivet out. I ended up using 470AD4-6 for 3 of the rivets. I'd advise anyone else just to start off with this size (or atleast check for the 1.5 diameter length instead of just going by the plans.)

Additionally I decided to just order a new 411 assembly because I wasn't comfortable with the amount of beating required to get the bad rivet out.

Stan
 
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Another consideration.....did you deburr your parts first???? also, is there any binding with the bearing and brackets????
 
yes...

I did debur and there doesn't appear to be any binding of the bearing or distortion of the brackets. I decided to order new 411 parts.

Stan
 
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Rivets too short

I have just arrived somewhere close there and found the -5 length rivets too short for the HS-411 to VA-146 bearing assembly. I used them per instructions. The shop head diameter slips over the gauge what is obvious to me, because of the shorter length. But the formed shop heads look good to me.

I am also new and have just started to build, so I didn't want to experiment with longer rivets, when the instructions explicit call for a -5. I now assume that this is good to go, also when I read some of your posts.
Thanks a lot for :) for all comments and for the great forum topics here.
 
squeezer

Yukon said:
You are going to love the air squeezer! I sleep with mine!
Click to expand...

That's why my wife is upset. It doesn't keep the bed as warm though. Love mine too!

I use SW primer too, but mine is the same stuff Vans uses on the QB. P60G. My first few parts were way to heavy. It might cause the problem you mention. If it's a two part wash primer like P60G, it should be really thin. I can easily see my markings through the paint.
 
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