Please Rescue me - and my Motivation

Hi,

When riveting the front spar with a rivet gun (HS-702 front spar, HS-710 REINF.ANGLE, HS-714 SPLICE ANGLE) and the subsequent drill of a damaged rivet, an error happens. Besides drilled (the first time).

During the subsequent attempt to set right and left of the damaged rivets two relief rivets, a rivet head again been damaged and when I drill out the hole, it gone wrong (the second time).

Is there a chance to Rescue the components or should I order new Parts ? What is the best way to "match" new Parts with the other already drilled, dimpleled and primed Spars and Skins ?

Achim (sorry for the google-translator english)
PS: Will order a pneumatic rivet squeezer now...

It appears that you have a "figure 8" hole where a flush rivet was installed too close to a button head rivet. The pieces with this type hole need to be replaced.

Match drilling parts is fairly easy. You align and secure the pieces then drill through the existing holes and into the new part(s).

A good idea would be to draw centerlines on your parts so the rivet patterns are uniform, and only drill out rivets which are truly awful. Van's has said repeatedly that drilling out a marginal rivet often leads to a fix that is worse than the original rivet.

Also, it looks like you are having trouble with button head rivets. I did too - it took me the whole empennage kit and a new rivet set before I stopped dinging the occasional factory head. More practice is in order, I believe. You will need to drive button head rivets in other places in the airplane where a squeezer will not reach, so you might as well get good at driving them with a rivet gun.

Don't let a few mistakes while you're learning the basic skills slow you down. It is like riding a bicycle - daunting and very hard initially, but once you have the hang of it, it becomes almost second nature.

order new parts! Small cost for peace of mind......

+1 for new parts. Also something to consider when drilling out a bad rivet. You only drill off the head, not through the entire rivet. If you drill only enough to remove the head of the rivet, then use a punch to remove the rest of the rivet you eliminate the risk of elongating the hole through the part as you have done here. Drilling off the heads required practice also. Have fun

Joachim, same as what everyone else said. We've all had a learning curve to go through (not sure that learning curve ever ends ), so keep practicing. I don't know if you have other builders in your area who can help, or perhaps can attend a workshop of some kind, but that might be helpful for you. Otherwise, do a search on here for typical rivet gun settings for different types and sizes of rivets and practice away on some sheet metal. And, yeah, you'll like having a squeezer, but you won't be able to use it all the time, so rivet gun practice is a necessity.

Once you've driven all those practice rivets, take some time and practice drilling them out. I get best results if I first center punch the rivet, then use my variable speed DeWalt electric drill on slow speed to start and slowly increase the speed until I've got a good hole in the head (and ONLY the head). Then use my punch and break off the head, then lightly hammer to punch out the shop end. Don't drill the rivet all the way through -- that's how you end up with an enlarged hole. You'll get good at this in no time, and again it will be a necessary skill. No one's going to drive 14,000 perfect rivets each time!

If this is the worst problem you have with your build, you'll be just fine. Just be ready by the time the new parts arrive.

Later,

Herr Gothe,

I had trouble driving my button head rivets with the rivet gun. They were just like yours, after help here, I turned the pressure down substantially and then the driver would not hop off the rivet head. Start low on pressure (40 psi ?) and work your way up using these pieces as practice. I am sure you will find many uses for these pieces in their second life before your airplane is done.

With a little practice, confidence will cause the brain to swell slightly and work more effectively to overcome any little potential issues.

Happy Riveting!

One more thing - when drilling out the rivets, don't be shy about angling your drill over 10-20 degrees as needed to get the hole in the middle. If it is a critical part and area, I begin with a reduced size drill bit to begin. Also, contrary to recommendations sometime I will drill through the rivet shank (after popping the head off and ensuring the hole does not intersect the parent material) to relieve the compressive stresses. This is a skill you will develop slowly until you grab the drill and remove a rivet without thinking. Again, practice - practice - practice.

Welcome to VAF!

Achim, welcome to the good ship VAF.

I also would recommend replacement of the bad parts, and more importantly, you need to learn how to drill out a bad rivet.

The info from Dan below is correct--------drill out the head only.

RVDan said:

+1 for new parts. Also something to consider when drilling out a bad rivet. You only drill off the head, not through the entire rivet. If you drill only enough to remove the head of the rivet, then use a punch to remove the rest of the rivet you eliminate the risk of elongating the hole through the part as you have done here. Drilling off the heads required practice also. Have fun

Click to expand...

Another way, is to get a longeron yoke and hand squeeze those.

There are excellent lessons in that piece you have there.

Replace some of the parts. But work with them as if they were going on an airplane for the lessons they will provide.

With the parts that you have left. Drill out and remove every rivet. Pay close attention to your technique here. If you learn this skill early, you will pay less in parts for the duration of your project.

From above

+1 for new parts. Also something to consider when drilling out a bad rivet. You only drill off the head, not through the entire rivet. If you drill only enough to remove the head of the rivet, then use a punch to remove the rest of the rivet you eliminate the risk of elongating the hole through the part as you have done here. Drilling off the heads required practice also. Have fun

Drill just far enough into the rivet head (be careful to keep the drill square and centered) such that you can insert a punch into the hole and gently pry off the head of the rivet. (#30 for this job) Now, if you've only gone deep enough to grab the head of the rivet, the hole will be intact. Ideally, you want to be centered on the hole and not so deep that you've elongated a hole. If there are not any pieces of rivet on the rivet shank it can now be punched out. I find that a spring actuated push-punch on one side and a cushioned tungsten bucking bar on the other works well for this task.

Once you have all of the rivets out. Inspect the parts to see if you'd do something different next time, remove any usable parts that you will build with and then Cleco, Clamp and rivet the rest of them back together. The parts may not want to stay straight. Fun.

These rivets may be harder, much harder to set straight. These will also be potentially too short due to the expansion of the last rivets in their holes so use some judgement here too... maybe a half size larger? Longer rivets are also harder to keep from clenching. Another lesson.

Drill again if you want to.

For the price of the new parts, you've got lessons a perfect tool box from vans can never give you.... well unless you take it back apart again.

Second word of advice. Seek the approval of Van's engineers before you decide to use any questionable parts. HERE, You may receive some well intentended but incorrect advice to forge ahead when you should instead do something quite different. Please don't let a language barrier keep you from doing the safest thing.

Your matched hole kit will accept the parts you've alread drilled... like the skins You shouldn't need to replace those. The only ones you will need to replace are the ones that have unacceptable work errors.

Hand squeezer with Longeron head... gets it done quick and easy and cheaper than pneumatic squeezer. If you still want pneumatic squeezer, still get longeron head for it.

Bum to the gun!

Joachim

One tip is to put a bit of masking tape on the rivet set I have found it helps prevent things moving. Next apply firm pressure from the hip (bum to the gun) and once the set is square to the head of the rivet press firmly. The dolly is held square to the shop head side but held more loosely.

Personally I dont like hand squeezers as I find they are more likely to drive the shop head offset.

As the other guys say practice a lot more before building the structural stuff.

As for motivation go for a flight in any RV, watch the videos put on this site. RV's are fantastic aircraft........ but it takes time and patience to build them.

One thought on using the hand squeezer on -4 rivets, maybe it's just my getting too old, but I used one on the -4 rivets on my HS, and I needed two gorillas and an elephant to help me squeeze them. Finally thought of a better way, set the squeezer a little wide, and squeezed them only partially, reset the squeezer to final length, and squeezed them the rest of the way. Did not notice any work hardening in just the two squeezes, and I ordered a pneumatic squeezer the next day.

Hand Squeezer

Achim,
You're receiving great advice from all the gentlemen above. I use a pneumatic hand squeezer every chance I get, because I'm most successful riveting with that tool.

Don't feel bad about replacing the parts...it happens. Like the others said, use the old parts to practice practice practice. I messed up the exact same pieces when I started my empennage, but it was because I misaligned the rivet holes (yes, if there's a way to misalign, I'll find it).

Big Picture for your motivation: This is a MINOR setback...and a learning opportunity to perfect your skills and techniques. You're going to do a great job.

Gebäude halten, mein Freund. Bauen auf!

OLDSAM said:

One thought on using the hand squeezer on -4 rivets, maybe it's just my getting too old, but I used one on the -4 rivets on my HS, and I needed two gorillas and an elephant to help me squeeze them. Finally thought of a better way, set the squeezer a little wide, and squeezed them only partially, reset the squeezer to final length, and squeezed them the rest of the way. Did not notice any work hardening in just the two squeezes, and I ordered a pneumatic squeezer the next day.

Click to expand...

Where's the fun in that? Built my airframe with a hand squeezer, good workout

WAM120RV said:

Next apply firm pressure from the hip (bum to the gun) and once the set is square to the head of the rivet press firmly. The dolly is held square to the shop head side but held more loosely.

Click to expand...

Yeah, don't be afraid to really put pressure on the gun; that'll also help keep it from sliding around or jumping off the rivet.

Also, I rarely bother trying to squeeze 1/8" rivets. My hand squeezer isn't much fun on those. When I can, I like to clamp a bucking bar in the bench vise, hold the part in my left hand, and shoot with my right. I get nice consistent rivets that way, with minimum effort. It works great for the reinforcement straps on the rear wing spar...

Motivation!

+1 to all the good advice from the VAF brain trust ... I rely on their experience every day.

Here's some real motivation .. from VAF member Bill Rogers. I don't have the original post, but I did save the link. Watch this and you'll be reaching for the rivet gun in seconds.

Keep up the good work; it's all about learning!


https://vimeo.com/75728303

I'd order the new parts (hey, I DID order the new parts).

And people are right. The secret really is turning down the gun and going much slower. Don't hold the bucking bar so tight against the shop head that it can't do it's bucking-bar thing. That's a common mistake, too.

Don't fret. It's a big fraternity.

Hi,

thank you for all good tips. I will order replacement Parts and will practice drilling and riveting with the old Parts.

I was flying yesterday after 1 and 1/2 Month on Ground with my LSA (Remos G3). Motivation is back

Achim

But Van's says...

This is not a comment on the particular situation above, but I'm interested in everyone's opinion on this part of Van's build manual:

(From Section 5: CONSTRUCTION MATERIALS, PROCESSES AND USEFUL INFORMATION http://www.vansaircraft.com/pdf/Section_5_R11.pdf )

"DRILLING OUT RIVETS
One of the common calls we get is ?I had to drill out a bad rivet and now the hole is oversize. What do I do??.

Sometimes this is done multiple times in the same hole and now the hole is so large that the builder has to use a bolt and nut instead of a rivet. See below.
EXCERPT from Alcoa Aluminum Rivet Book, dated 1984.

?The standards to which driven rivets should conform are frequently uncertain. In addition to dimensions and perfection of shape, inspection is concerned with whether the drive head is coaxial with the shank (not ?clinched?) and whether there is excessive cracking of the heads. It has been determined that even badly cracked heads are satisfactory from the standpoint of static strength, fatigue strength and resistance to corrosion. (Poorly set and cracked) rivet heads were tested in tension to determine how well formed a head has to be in order to develop full strength. The tensile strengths of all the rivets were within five per cent of the strongest. The test indicated that minor deviations from the theoretically desired shape of head are not cause for concern or replacement. The second rivet that is driven in any one hole likely to be more defective than the first because the hole is enlarged and rivet will be more likely to buckle and form an imperfect head.
Tests have shown that very small rivet heads are sufficient to develop the strength of the rivet shank, even when the rivets are subject to a straight tensile pull?.where a large head is not needed for appearance, smaller sizes of drive head should be used to decrease the required driving pressures.?

Click to expand...

In the same sentiment, Van's builder assistance is often heard saying "you're building an airplane, not a watch".

I'm certainly not condoning shoddy workmanship, but the above would make it sound like rivets with a bit of the manufactured head spread out on the edge, a slightly oblong shop head, etc., are better left in the hole rather than risking the potential damage from drilling them.

Very interested in your thoughts...

ToadMan8 said:

... the above would make it sound like rivets with a bit of the manufactured head spread out on the edge, a slightly oblong shop head, etc., are better left in the hole rather than risking the potential damage from drilling them.

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Absolutely. There was a reason the rivet was poorly driven in the first place - often because it is/was in an awkward location. That won't change the second, third, or fourth time around. So unless the rivet is a real butcher job, leave it alone.

If it is a real butcher job, learn to drill off the factory head and drive the remains of the rivet out with a punch. If you never drill deeper than the factory head, you'll never damage a part drilling out a rivet.

Support you work, firmly. Clamp it down to a solid surface and insure that it will not move and bounce around. You will be surprised at how smoothly and easily they will set if your work is not moving around. This is a very common error made by new builders.

Motivation

Hi Achim

I am about at the same building stage as you are and I am a first time builder. I wanted to let you know that I did the front spar of the HS twice even though in the end it was not really necessary. More over I did my HS-710 3x and the HS-405 2x (due to minimum edge distance issues and elongated holes).

All parts costed me just a few $ but time and motivation were much more significant, A lot of other builders went through all that too. Just take your time and hold on to your blueprints and assembly instructions. I have read that the HS is not an easy part to build.

If you like to share your thought, I am with you and we can write in German as well.
So I encourage you to keep on building. It's fun and in the end when you fly your own airplane you will have a much better feeling to have re-worked all the messed up parts.

hope this helps

Don't feel bad about ordering new parts, even though they take some time to arive from the US.

Here is a picture of just some of the parts I had to replace during my build. If that is the only thing you mess up, you are doing GREAT!


(Click to enlarge)

Hi,
Spare Parts are now here, but I stop working at my horizontal Stabilizer because of the Service Bulletins. I will wait for new designed HS-404/HS-405 (HS-00005/HS-00006 ?? ) and the doublers.

Achim