jim miller
Well Known Member
Has van made any statements concerning using conventional rivets on the RV-12? I have a full Avery tool kit and just like the idea of using flush AN rivets.
Jim Miller
Jim Miller
Van's Air Force
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RV-12/AN rivets
- Thread starter jim miller
- Start date
I can't answer for Van, but...
I have done this on several airplanes that were designed for pulled rivets and the designers have never had a problem with it. I'm using solid, flush rivets everywhere I can on my bi-plane. I also did this on a Moni Motorglider and a ZenAir CH601HDS.
I have done this on several airplanes that were designed for pulled rivets and the designers have never had a problem with it. I'm using solid, flush rivets everywhere I can on my bi-plane. I also did this on a Moni Motorglider and a ZenAir CH601HDS.
jim miller
Well Known Member
Mel
I am sure there are areas where you can't use AN but using the equivalant flush pulled rivet should work. This is going to be a big issue with a lot of RV-12 builders and I hope Van offers a kit variation for those who want to use conventional rivets.
Thanks
Jim Miller (Tennessee)
I am sure there are areas where you can't use AN but using the equivalant flush pulled rivet should work. This is going to be a big issue with a lot of RV-12 builders and I hope Van offers a kit variation for those who want to use conventional rivets.
Thanks
Jim Miller (Tennessee)
Mike_ExpressCT
Well Known Member
Jim,
Just as Mel has said, there are many examples of aircraft flying that were designed to use pulled rivets, but the owner used solid rivets instead without any problems.
However, I also remember reading that, since pulled rivets were being used, Van didn't worry about things such as flange direction in the wing ribs, among other locations, which would make solid rivets much harder to buck.
Looking back, it was said that Van designed the -12 to use pulled rivets for two primary reasons; first, ease and speed of building, and second, because top speed is not a primary concern with an LSA.
My advice would be to call Van's in this matter. I'm sure that solid rivets would be plenty strong for a substitute, but driving and bucking them in certain areas may be a problem.
Just as Mel has said, there are many examples of aircraft flying that were designed to use pulled rivets, but the owner used solid rivets instead without any problems.
However, I also remember reading that, since pulled rivets were being used, Van didn't worry about things such as flange direction in the wing ribs, among other locations, which would make solid rivets much harder to buck.
Looking back, it was said that Van designed the -12 to use pulled rivets for two primary reasons; first, ease and speed of building, and second, because top speed is not a primary concern with an LSA.
My advice would be to call Van's in this matter. I'm sure that solid rivets would be plenty strong for a substitute, but driving and bucking them in certain areas may be a problem.
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Actually I have found the opposite to be true. Since normally 1/8" blind rivets are used, the spacing is typically 2", whereas typical spacing for 3/32" solid rivets is 1 1/4". If the holes are pre-punched at 2" one would need to use 1/8" solid rivets. This is what I did on the Moni. On the Zenair, nothing was pre-punched, so I used 1 1/4" spacing and 3/32" rivets.Rick S said:
Mel said:
Since Van is pre- punching the 12 with 1/8? holes, designed for ?ready to pull? 1/8? pull rivets, we will be forced to use AN426-4 rivets, rather that ?3s. Mel, do you see this as being a problem with the light skins that we will encounter on wings and control surfaces? Your experience with this process on your biplane, Moni Motorglider and a ZenAir CH601HDS, should qualify you best to answer that question. I, like you, would prefer AN426 rivets over and pull rivets, where I thought that I could do a decent job of driving and bucking them. It?s not the speed gain that takes me here. It?s the esthetics, smooth surface to wash and wax, and a little added strength without paying a weight penalty that interest me.
Appreciate your comments
Tom
sprucemoose
Well Known Member
One more thing to consider- when designing for solid rivets (flush or not) the designer has to allow for access to the back side of the rivet for a bucking bar. When designing for pulled rivets, the designer is free from this constraint, and can design a completely "boxed in" structure with no bucking bar access. As a result, you may have a difficult time bucking a lot of the rivets.
I don't know how much of this applies to the 12 specifically. I'm currently TC'ing a Zenith 701 project where the builder elected to use solid rivets instead of the called for pulled rivets. Hasn't been a huge issue yet, but the 12 might be another story.
I don't know how much of this applies to the 12 specifically. I'm currently TC'ing a Zenith 701 project where the builder elected to use solid rivets instead of the called for pulled rivets. Hasn't been a huge issue yet, but the 12 might be another story.
Couple weeks back I was wondering why the pre-punched holes aren't drilled as we do with our planes. First I considered that rivets we use might stress more holes than pull-rivets but that would be unlikely. Then I realised that we are putting great stress to the hole when we dimple them. So if anyone considers using solid rivets and dimpling the holes, I quess drilling/reaming holes would be appreciated... any thoughts?
And I quess changing rivets for RV-12 could even double building time...
And I quess changing rivets for RV-12 could even double building time...
Jack Fromm
Member
Mel said:
I suppose Van's should be the one to ask this question of as well, but since I don't want to bother them at this stage of the game, I'll pose it here. I see that they say that the holes on the -12 kit will not require match drilling or deburring. Is that because a pulled rivet does not expand in the hole and thus does not provide a stress concentration to start a crack on a hole which has not been stess relieved by match drilling? And if that's the case, can I assume that will mean that one would have to match drill and deburr any holes he wishes to put a solid rivet in? And can you even match drill the holes if they are not slightly undersize as in the current kits?
jim miller
Well Known Member
Jack
One thing to consider regarding hole size is the pull rivet is 1/8" and the AN rivet is a #30 which is slightly larger so match drilling could occur. I agree that some areas may be inaccessible for bucking due to the RV-12 design but in those areas use flush pull rivets (keeping in mind the different dimpling angles required)
Jim Miller
One thing to consider regarding hole size is the pull rivet is 1/8" and the AN rivet is a #30 which is slightly larger so match drilling could occur. I agree that some areas may be inaccessible for bucking due to the RV-12 design but in those areas use flush pull rivets (keeping in mind the different dimpling angles required)
Jim Miller
One thing that seems to be completely forgotten in this thread is that when the folks at Vans' designed the 12 the reason they went with pulled rivets was that there was no great perceived need for a slick clean design. That is to say the category the 12 was designed for almost begs for a bit of a dirty design. Pulled rivets fit the bill. Clean a 12 up to much and ya might as well be building a 3,4,7,8,9 or a 10.
nice dimples
I have seen a Sonex Built with the flush pulled rivets and it made a huge improvement in appearance, (I swear to god it did) but still has the holes. I've always been told that dimpling the skins actually made the connection stronger after riveting and improved the shear resistance, but it would add a lot more labor and time to the build. Maybe Vans could be pursueded to offer a flush pulled option, and not leave the builder figuring out what to do with a couple thousand leftover pulled rivets if he chose to dimple.
I have seen a Sonex Built with the flush pulled rivets and it made a huge improvement in appearance, (I swear to god it did) but still has the holes. I've always been told that dimpling the skins actually made the connection stronger after riveting and improved the shear resistance, but it would add a lot more labor and time to the build. Maybe Vans could be pursueded to offer a flush pulled option, and not leave the builder figuring out what to do with a couple thousand leftover pulled rivets if he chose to dimple.
The BD4 and BD5 used Avex pulled rivets very successfully in the 70's (and also proseal for tanks and high stress joints). I finished my BD4 in 1979 and later replaced the fiberglass wing panels with aluminum ribs and skins and used 1/8" Avex CS pulled rivets. The wings turned out very nice.
I did decide to fill the mandrel holes to avoid the dirt collecting hole. It was a little tedious to dab epoxy micro mix into the holes with a toothpick (I'm sure there is a better way...), but it went quickly and worked out well.
Avex pulled rivets are very strong and when used in a PROPERLY designed joint are safe. With an airpowered puller, installation is quick and easy. The nominal 1/8" rivet actually requires a #29 hole which is a little larger than 1/8".
I sold my '4 a few years ago to buy a Debonair. I often miss the ol' BD. It hauled me and my family all over the country at a comfortable 180+mph with a O-360/CSP for over 20 years. It was a very strong plane and easily modified to use bigger engines, often auto engines. And its boxy look was surprisingly fast.
Although Bede had many problems with the BD5 and his business, he was a true pioneer in the kit business. And let's not start a thread on this.
I picked up my BD4 kit in 1973 from the factory and it had every part needed to build a flyable VFR aircraft with exception of a engine, battery, paint and avionics...and each part/piece/nut/bolt/accessory in the kit was packaged in a plastic bag or box that was crossed referenced on the professionally done plans. I could have bought the full kit which included a new Lycoming and a finishing kit. He also had a accessory catalog with options, instruments, avionics and parts.
I did decide to fill the mandrel holes to avoid the dirt collecting hole. It was a little tedious to dab epoxy micro mix into the holes with a toothpick (I'm sure there is a better way...), but it went quickly and worked out well.
Avex pulled rivets are very strong and when used in a PROPERLY designed joint are safe. With an airpowered puller, installation is quick and easy. The nominal 1/8" rivet actually requires a #29 hole which is a little larger than 1/8".
I sold my '4 a few years ago to buy a Debonair. I often miss the ol' BD. It hauled me and my family all over the country at a comfortable 180+mph with a O-360/CSP for over 20 years. It was a very strong plane and easily modified to use bigger engines, often auto engines. And its boxy look was surprisingly fast.
Although Bede had many problems with the BD5 and his business, he was a true pioneer in the kit business. And let's not start a thread on this.
I picked up my BD4 kit in 1973 from the factory and it had every part needed to build a flyable VFR aircraft with exception of a engine, battery, paint and avionics...and each part/piece/nut/bolt/accessory in the kit was packaged in a plastic bag or box that was crossed referenced on the professionally done plans. I could have bought the full kit which included a new Lycoming and a finishing kit. He also had a accessory catalog with options, instruments, avionics and parts.
rangelyflyer
I'm New Here
Dimpling for pulled rivets
There is no dimpling for pulled rivets. You put the rivet in the gun, match up the holes, put the rivet in the hole and pull the trigger. It requires about the same effort as stapling to pieces of paper together. The bit on your gun should have a concave shape so that the head of the rivet forms an aerodynamic shape.
There is no dimpling for pulled rivets. You put the rivet in the gun, match up the holes, put the rivet in the hole and pull the trigger. It requires about the same effort as stapling to pieces of paper together. The bit on your gun should have a concave shape so that the head of the rivet forms an aerodynamic shape.
jim miller
Well Known Member
There are both dome head and flush pulled rivets. The flush pulled rivet differs slightly from a AN flush rivet in the head angle and you have to use dimple dies specifically for the pulled flush rivet.
Jim Miller
Jim Miller
not all rivets are created equal
Just to throw some other thoughts into this discussion...
Remember that there are a LOT of different types of pulled rivets. The ones that come in your handy dandy Home Depot hand riveter are for holding gutters togeter. Then, there are the high end CherryMax versions that are actually used on lots of airplanes. I'm not sure what rivet Van's used on the RV-12. I've built a Sonex and it uses Cherry N rivets. http://www.avdel-global.com/products/datasheet/imperial/breakstem/N_Rivet_CCPS_LS_CS_inch.pdf
Mel is right in that the angle of the flush versions are 120 degrees with this particular rivet. Don't let the "pop rivet" term fool you. A 1/8" Cherry N rivet is actually stronger that an AN-4 rivet. As for subsituting, there is no way I would change rivets without getting the a-ok from the designer. These little guys hold everything together
.
To me the biggest advantage to using pulled rivets is speed in building. It takes WAY longer to rivet assemblies together on the -10 than it did the Sonex. Yeah, I know there are lots more rivets , but rivet for rivet, its way faster. Who knows, the protruding rivets might grow on you. I like the way the Sonex looks with them.
I wonder what a Ford Trimotor would look like with flat skins.... .
Just to throw some other thoughts into this discussion...
Remember that there are a LOT of different types of pulled rivets. The ones that come in your handy dandy Home Depot hand riveter are for holding gutters togeter. Then, there are the high end CherryMax versions that are actually used on lots of airplanes. I'm not sure what rivet Van's used on the RV-12. I've built a Sonex and it uses Cherry N rivets. http://www.avdel-global.com/products/datasheet/imperial/breakstem/N_Rivet_CCPS_LS_CS_inch.pdf
Mel is right in that the angle of the flush versions are 120 degrees with this particular rivet. Don't let the "pop rivet" term fool you. A 1/8" Cherry N rivet is actually stronger that an AN-4 rivet. As for subsituting, there is no way I would change rivets without getting the a-ok from the designer. These little guys hold everything together
.To me the biggest advantage to using pulled rivets is speed in building. It takes WAY longer to rivet assemblies together on the -10 than it did the Sonex. Yeah, I know there are lots more rivets
, but rivet for rivet, its way faster. Who knows, the protruding rivets might grow on you. I like the way the Sonex looks with them.I wonder what a Ford Trimotor would look like with flat skins....
.
