Frog Hobson
Member
Trying to decide which one to get, I know there are limited rivets to drive so leaning towards the 3x. What say those who have built an RV or two?
Thanks,
Mike
Thanks,
Mike
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2X or 3X gun
- Thread starter Frog Hobson
- Start date
My preference is the 3X; fewer blows to set the rivet and more mass in the gun. That said, I have used the 2X gun in a few places where less bulk is beneficial.
I always recommend a 2X for 3/32 rivets. Since (likely) all of the driven rivets in the RV-15 will be 1/8, A 3X would be the best choice.
Frog Hobson
Member
Thanks, I was leaning that way. 3x it is
I concur with Scott. This lets me use the same line pressure for both sizes of rivets.
Dave
Dave
Only 2X for me.
Carl
Carl
Same here, however not all rivet guns are created equal.
+1 for the 2x gun. That said I’ve Borrowed a 3x from my neighbor from time to time.
So far this turns out to be like a poll with no clear winner, few reasons given that people would prefer one over the other.
I was looking into the same question. Most of what I saw indicated that a 2X is easier to do quality work when being used for rivets up to 1/8. If you need to do 5/32 it would not work and a 3X would be more appropriate. Are there any comments on whether that is overstated? Is the difference in 'usability' so minor that it's better to just have the extra capacity of the 3X? If you knew for sure you would not need to do 5/32, would the 3X guys still say 3X? Is a 2X just barely sufficient for 1/8, and you better have a 'better' gun in that case?
The only experience I have is using an air hammer. I intend to upgrade that if/as necessary.
I was looking into the same question. Most of what I saw indicated that a 2X is easier to do quality work when being used for rivets up to 1/8. If you need to do 5/32 it would not work and a 3X would be more appropriate. Are there any comments on whether that is overstated? Is the difference in 'usability' so minor that it's better to just have the extra capacity of the 3X? If you knew for sure you would not need to do 5/32, would the 3X guys still say 3X? Is a 2X just barely sufficient for 1/8, and you better have a 'better' gun in that case?
The only experience I have is using an air hammer. I intend to upgrade that if/as necessary.
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A larger gun offers more flexibility, but also requires more precise control of air volume and trigger control. I only have a 4x gun and built two planes with it. Not so good for the novice though. Still have a couple smilies from when i thought i could let my kids try the riveting vs bucking on the few occasions i had help. Things happen faster with the heavier guns.
Sioux 2X
The X rating on a rivet gun is an indication of how hard each gun will hit a rivet on each cycle with a given amount of air pressure and flow applied.
The hit is produced by a weighted piston that is cycling fore and aft in the barrel, and hitting on the aft face of the rivet set.
As the X rating of a gun gets higher, the barrel gets longer, which provides opportunity for it to get accelerated to a higher speed. This increase in acceleration increases the available, kinetic energy for the hit on the rivet set.
So if you would connect a 2X and then a 3X and then a 4X to a hose without changing the pressure the 4X will hit a lot harder than the 2X
The problem is there is no standard of how much the difference is because every brand is slightly different.
This means that there are two variables that you can apply to change how hard you are hitting a rivet. One is to select a rivet gun of a different X value, and the other is to adjust the air pressure up or down depending on what change is needed.
Higher quality guns can operate well at a wider range of air pressure, which is why some people say they use a ?x For all rivets on an RV. The lower price, consumer guns, which generally do a pretty good job, don’t tend to function well at as wide of a air pressure range.
Since a lot of of the RV builder community tends to use the more consumer grade rivet gun, that is why I always recommend a 2X for 3/32 rivets and a 3X for 1/8 inch.
If someone doesn’t have the luxury to have both then it is possible to get by with just a 2X but it can be a struggle on heavier substructure areas to set 1/8 inch rivets.
Personally, I prefer a 2X for any 3/32 rivets, regardless of how high quality the gun is. In my opinion, even a really high quality 3X still hits harder than is needed, even with the air pressure dialed back.
The hit is produced by a weighted piston that is cycling fore and aft in the barrel, and hitting on the aft face of the rivet set.
As the X rating of a gun gets higher, the barrel gets longer, which provides opportunity for it to get accelerated to a higher speed. This increase in acceleration increases the available, kinetic energy for the hit on the rivet set.
So if you would connect a 2X and then a 3X and then a 4X to a hose without changing the pressure the 4X will hit a lot harder than the 2X
The problem is there is no standard of how much the difference is because every brand is slightly different.
This means that there are two variables that you can apply to change how hard you are hitting a rivet. One is to select a rivet gun of a different X value, and the other is to adjust the air pressure up or down depending on what change is needed.
Higher quality guns can operate well at a wider range of air pressure, which is why some people say they use a ?x For all rivets on an RV. The lower price, consumer guns, which generally do a pretty good job, don’t tend to function well at as wide of a air pressure range.
Since a lot of of the RV builder community tends to use the more consumer grade rivet gun, that is why I always recommend a 2X for 3/32 rivets and a 3X for 1/8 inch.
If someone doesn’t have the luxury to have both then it is possible to get by with just a 2X but it can be a struggle on heavier substructure areas to set 1/8 inch rivets.
Personally, I prefer a 2X for any 3/32 rivets, regardless of how high quality the gun is. In my opinion, even a really high quality 3X still hits harder than is needed, even with the air pressure dialed back.
Great summary.
Your last statement I would question with regard to a 3X gun hitting harder than needed, though. If you consider that the amount of energy that it takes to set a given rivet is independent of the gun used to set it, the difference then becomes how many times the 2X needs to hit the rivet to set it versus the 3X. The 3X, as you said, has more energy per stroke than the 2X and therefore will set the rivet in fewer strokes than the 2X (unless, of course, you dial the pressure down on the 3X). The amount of energy necessary to set the rivet remains the same, so I am not sure how the 3X hits harder than necessary. It's bbbrrrttt, bbbrrrttt with the 3X and bbbrrrttt, bbbrrrttt, bbbrrrttt with the 2X.
As a data point, I run my 3X gun at 40-45 psi; seems to work fine.
It still really comes down to personal preference (within the capabilities of the gun)...
Think “finishing hammer” verses “framing hammer”
I originally just bought a 2X for the tail-cone, then saw the “hardening” effect of a 2X improperly used on the 1/8” rivets.
So I sold a rifle and used the money to buy a 3X rivet gun.
(Just kidding, you never sell a gun in Montana, you just buy more of them.”
-cappy
I originally just bought a 2X for the tail-cone, then saw the “hardening” effect of a 2X improperly used on the 1/8” rivets.
So I sold a rifle and used the money to buy a 3X rivet gun.
(Just kidding, you never sell a gun in Montana, you just buy more of them.”
-cappy
I have a 3X which came with my RV-14 tool kit. Didn't know the differences at the time. I did the entire aircraft with it. So I am good to go with it on the 15.
What I never did figure out was the small regulator on the gun. I eventually took it off and just controlled the pressure at the compressor to 42 - 43 PSI.
Is there any value to use the small regulator on the gun? If there is I would like to figure it out.
What I never did figure out was the small regulator on the gun. I eventually took it off and just controlled the pressure at the compressor to 42 - 43 PSI.
Is there any value to use the small regulator on the gun? If there is I would like to figure it out.
I found that little regulator to be pretty worthless. I removed it. Instead, I made a couple of mini in line regulators. I keep my system pressure constant and plug the inline regulator at the wall. Each regulator is set for the particular gun I am using so I don't have to reset every time I change tools. Believe it or not, the HF mini regulators work pretty well and the price is right especially if you get them on a coupon. Latest one was 30% off. They also have the Chief brand pneumatic pull riveter which was 20% off. Looks pretty nice but we will see...
dnimigon
Well Known Member
Could you post post pic of that regulator you got from HF
I was skeptical but thought for that price I would try it. It worked great for my entire -10 build and is still working. I have hard plumbed air system in my shop. I keep the system at 140 psi and then use these smaller regulators at each outlet. If you shop the sales, the regulator and two fittings end up less than $10...
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Jjackh10
Well Known Member
We have this set up both in the hangar and the garage. 100% worth it as it provides much more precise and even metering of pressure compared to the regulator on the compressor.
I have the McGraw and it's miles better than the old blue one they sold.
I understand you’re thinking, but the reason you are wrong is because there is an additional factor we are wanting to control besides just how long it takes to set the rivet.Great summary.
Your last statement I would question with regard to a 3X gun hitting harder than needed, though. If you consider that the amount of energy that it takes to set a given rivet is independent of the gun used to set it, the difference then becomes how many times the 2X needs to hit the rivet to set it versus the 3X. The 3X, as you said, has more energy per stroke than the 2X and therefore will set the rivet in fewer strokes than the 2X (unless, of course, you dial the pressure down on the 3X). The amount of energy necessary to set the rivet remains the same, so I am not sure how the 3X hits harder than necessary. It's bbbrrrttt, bbbrrrttt with the 3X and bbbrrrttt, bbbrrrttt, bbbrrrttt with the 2X.
As a data point, I run my 3X gun at 40-45 psi; seems to work fine.
It still really comes down to personal preference (within the capabilities of the gun)...
Someone else mentioned the analogy of the difference between a heavy hammer and a finish hammer. Using that analogy with a nail, someone that is skilled might be able to drive a 16 penny nail with just one hard hit using a sledgehammer, but a novice might take six hits with a light framing hammer. So with the heavy hammer, the nail went in quickly, but what do you suppose the surface of the board looks like where it was hit by the sledgehammer. Quite different than where the board was hit on the last hit by the light hammer.
The same thing comes into play on light Aircraft structure with different sized rivet guns. Sure, the higher X value will set the rivet quicker or with fewer hit cycles, but is that the only goal?
In my mind, no. We also want the nicest finish quality possible.
A lot of people are unable to detect the nuance difference, but using a rivet gun bigger than is necessary, does produce a difference in surface finish quality. Especially when we factor in lower skill level.
This is largely about what the substructure is like that the riveting is being done on.
Setting 3/32 inch rivets where skins attach to a 1/8 inch thick longeron can be done with a 4X gun with no noticeable difference in finish quality because we are riveting in very solid resilient structure. Use that same 4X gun to set rivets in your .025 wing skin attaching to .025 wing ribs, and you will definitely see a difference in flatness around each rivet. It is no different between a 2X and a 3X gun on light structure, it just isn’t as dramatic of a difference.
So my recommendation of a 2X rivet gun for 3/32 inch rivets is for the purpose of trying to help less experienced people get the best finish quality possible.
I have been riveting on light aircraft structure for a long time and can get by with a 3X gun for most riveting, but I will still always grab a 2X when riveting 3/32 inch rivets on external skins.
As for people removing and throwing away the brass control valve that came with the rivet gun…. Comments like that just further reinforce how many people just never learn to detect the nuance differences that have an influence on riveting performance and finish quality.
I guess people don’t think about why a highly respected tool supply company would supply something with a tool they sell, when it is pointless to have?
I have one of those valves on every rivet gun I own. I say valve, because it is not a regulator. It is a needle valve that has a high level of very fine adjustment. It controls the hit rate of the gun by controlling the flow of air at the inlet.
Because of how a rivet gun works, if you vary the pressure and airflow at the gun inlet, you are also regulating how hard it hits versus just what X value of gun you have chosen. This allows someone skilled with riveting to vary how hard the gun hits, depending on what structure they are riveting on. I am constantly changing the setting on that valve as I move between heavier structure, such as a spar flange versus moving off the flange onto ribs out in the middle field of a skin.
So that little valve provides two benefits
All of my air lines are always at max system pressure (100 psi) and control of the rivet gun is done right at the gun itself. If ever any adjustment is needed, I can do it right there at the gun without going anywhere else in the shop. This also allows any air line to be used for any other tool such as a air drill or die grinder, without having to readjust the line pressure.
A secondary benefit to this is I know the gun is going to hit exactly the same as it did the last time I used it. If you are using a remote regulator to adjust your gun it is very difficult to get it set exactly the same each time.
As mentioned previously, this valve has a very fine adjustment. So if someone turns it just a couple of clicks and expects a big change, it’s understandable that they think it doesn’t do much. I think the other mistake is people attempt to use the valve with a line pressure set close to what they think would be the proper pressure for the rivet gun such as as 35 to 40 psi. In that case, since the pressure is already about what the gun should run at, you won’t see much change by adjusting the valve. If the line pressure is left at 100 psi you get the benefit of reduced influence of flow resistance through your system by supplying full system pressure right up to the gun inlet, and then control the gun with the valve.
BTW, this how the prototype shop has always been set up at Vans Aircraft.
Scott,
All true, but I am one of the guys that throws away the brass control valve.
The outcome is the objective. Your advice works but I prefer adjusting the air regulator for the rivets to be set. With time I knew within a a few psig the value needed for a particular job. So for me at least a much more repeatable process than the gun needle valve.
Carl
Thanks Scott, I appreciate your very detailed response. I was never told how that needle valve was designed to work. I was setting the line pressure at 42-42 psi and then not seeing any difference. I'll be reattaching and giving it another try.
Thanks
As always, your input is valued.
I will maintain that, at least for me, I prefer the 3x gun and did almost all of my -10 and a good portion of a -6 with it. I understand that your comments are including all possible builders. I am only concerned with one, so after many tests I settled on what works for me.
As far as the regulator goes, you must have a much different one than I did; mine was very coarse in adjustment. The system I have is working just fine so I see no valid reason to change it, not to mention getting the specified nuance with another gun.
Great discussion, though…always more than one way to do things.
Agreed, again I really appreciate all the comments here. I searched around some last week and the comments were less focused. Sometimes searching is just that way. Also, products come and go over time.
Is it possible to ask about brands of guns without things going too far off the rails? There seems to be some cutoff between 'consumer' guns and I guess higher end guns. Maybe it boils down to 'you get what you pay for' being good enough guidance for a shopper.
It's unlikely I would have an opportunity to try a few different ones so I would be flying blind on a purchase.
Alphalpha
Well Known Member
I would add a few nuances to Scott's well laid out comments.
AD rivets are made out of 2117 aluminum alloy which was specifically designed for general use rivets. But like most metals every time you forge it, it work hardens. So the goal to drive all 2117 rivets is to get them forged correctly in about 3 to 5 beats... give or take a few. And those beats have to bounce correctly which requires a constant rhythm between the bucking bar and rivet gun. However, the inertia of a smaller gun at higher pressure isn't the same speed as the inertia of a bigger gun at lower pressure because the opposing inertia of both the gun and the internal piston are at different rates for each model. So getting the rivet to forge while remaining in the same place and not distorting the base metal because the bar and gun aren't syncing well usually leads to a less than acceptable job. So bigger rivets use a bigger gun so that the 3 to 5 beat rhythm remains essentially the same. Bigger rivets also like the use of a heavier bucking bar.
The other nuance is joint stiffness affects the outcome when driving rivets. The gun bounces the rivet and the bar and hopefully the bar's inertia allows the shop end to be forged some as the bar accelerates away from the rivet without affecting the base material. A stiffer joint reduces the amount of bounce the gun can deliver through the rivet to the bucking bar. It is for this reason that the gun mounted air adjuster is very handy. I readjust it almost every time I rivet, or change what I am riveting. I normally like a scrap of 3/4" ply nearby for banging the gun against to adjust it.
Having said all this none of it matters when back riveting or squeezing, which is why I always try to use these techniques where I can.
I, for one, appreciate all the conversation on this. It's not a lunar module but there is serious riveting to be done, especially when it's joining the wing spar. I'm not worried so much about the beauty of it, but I sure am about structural integrity of the rivets. I've done a total of about 10 rivets in my life so far. I'll soak up all the information I can get.
Not good advice…. I drove a lot of the 470 rivets that are visible in the fwd upper fuselage…. They would have been impossible using a 2x gun.
If a 15 builder has no rivet gun and has to go out and buy one, getting a 2x instead of a 3x would make no sense.
To be fair, I advised a 3X gun a few days ago on this thread, but it feels like things have gone into the weeds with over-analysis. Failure to practice and develop a good technique will likely be more detrimental to the project than the particular rivet gun selection.
So far, Sections 22 and 23 of the -15, I think I have installed more solid rivets than pulled. Just guessing but maybe 60 each? We have options and I have shot about half and squeezed about half. Used a 3X. Working on the spar, there are plenty of solid rivets and only two so far have been for a nut plate. Quite a few would have been difficult/impossible to reach with a squeezer.
This is the information I was looking for so thank you for the follow up Louise! It sounds like I need to make this rivet gun choice very soon.
I'm not surprised about how many solid rivets you encounter. -12 builders are familiar with this, but I think a lot of people assumed the whole thing was pop rivets. The -12 has many many solid rivets and they are not just for nut plates. We did have the benefit of being able to squeeze all of them so bucking is new, but solid rivets do all kinds of heavy lifting throughout the structures.
Yeah, sorry. I want to build the thing and have a life. The worse thing I can imagine would be folks calling me a U-Tube "influencer".I'm sure Louise will be super busy this weekend editing all the Youtube videos she is going to post so we all can see what we are missing out on, right?
Thanks for the info, this is great!
