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Pneumatic squeezer does not work on rivets

L

localizer

Active Member
Hello everyone,
I have a new pneumatic squeezer which I have used for dimpling skins and ribs when I began working on my project. Then I took a year and a half off and now I'm back.
I picked up the squeezer and tried to buck some rivets, but nothing happened. It seems like there is no power in the squeezer. It does dimple though.
What am I missing? What PSI should I use?

Thanks,
Yuri
 
Check the adjustment of the rams. If it's set too tight it won't generate the force needed, so you need to just back off the adjustment a bit to get it to squeeze.
 
If you are trying to set 1/8" rivets, it may be necessary to set the squeezer so that you partially squeeze on the first pass and completely set them after readjusting the set lower. My understanding is that it has something to do with the stroke of the pneumatic squeezer where it generates the majority of it's power near the end of the stroke.

If you get no power setting -4 rivets, then I don't know what to tell you.... I've never had a problem with mashing and mangling them regardless of how I've set my squeezer.

Good luck.
 
Adjustment

FredMagare said:
If you are trying to set 1/8" rivets, it may be necessary to set the squeezer so that you partially squeeze on the first pass and completely set them after readjusting the set lower. My understanding is that it has something to do with the stroke of the pneumatic squeezer where it generates the majority of it's power near the end of the stroke.

If you get no power setting -4 rivets, then I don't know what to tell you.... I've never had a problem with mashing and mangling them regardless of how I've set my squeezer.

Good luck.
Click to expand...

That's the answer. The squeezer generates all its power at the end of the stroke.
Hopefully you have an adjustable ram. It's a pain to adjust with washers.
 
Back off a little

Counterintuitive as it seems, back off a little on the moveable die (less spacer washers under the head or, if adjustable, screw the plunger down into the body of the yoke).

The squeezer has very little power except in the last 1/8th inch or so of its travel when it develops something like 3000 lbs/sq in. Your problem is likely to be that it is contacting the rivet tail and being stopped before it gets to the range where full force is developed.

Try creeping up on the setting you need beginning with 'wide open' while setting some rivets in a test piece. However, if you repeatedly set the same rivet, it will work harden and you will get too close a setting before the rivet tail finally gets to the shape you are looking for. If if not work hardened, there is always some spring back so setting the gap by measurement alone is tricky. After a while, you will set the gap intuitively and get it right first time every time.
 
Thank you for answers, guys!

Yes, I do have adjustable rams. And yes, I have wrenched moving one up as high as I could to minimize possible screw up if I were to hold the squeezer at some wrong angle.

Ok, I will open it wider and see if I can mash a rivet. I was trying 3/32 and 1/8. I will report back.
 
Note that Avery sells low-profile sets that can give you a bit more at the end of the stroke.
 
Try this...

Agree with above. The pneumatic squeezers work on a cam action and develop the most force at the end of the stroke.

Try setting the squeezer shut height without anything in the gap. Set the open gap for the approximate finished height of a squeezed rivet. Then try it on your test piece (or just a plain rivet). Should get you close.
 
90 PSI

I ran mine at 90 PSI. It would squeeze -4 rivets with no problem. I would not expect any problems unless you are trying to squeeze really long rivets. As others have said, it generates more force the more it closes.

A mistake I occasionally made was to switch from shooting rivets with the gun (pressure set to 20-40 something psi) to the squeezer without resetting the pressure back to 90. It sure enough wouldn't squeeze at the lower pressure!
 
Shooting rivets

Dan Langhout said:
I ran mine at 90 PSI. It would squeeze -4 rivets with no problem. I would not expect any problems unless you are trying to squeeze really long rivets. As others have said, it generates more force the more it closes.

A mistake I occasionally made was to switch from shooting rivets with the gun (pressure set to 20-40 something psi) to the squeezer without resetting the pressure back to 90. It sure enough wouldn't squeeze at the lower pressure!
Click to expand...

Good thing you didn't use the gun at 90 psi!:eek:
One reason why I have a manifold and two hoses with regulators.
 
Dan Langhout said:
...A mistake I occasionally made was to switch from shooting rivets with the gun (pressure set to 20-40 something psi) to the squeezer without resetting the pressure back to 90. It sure enough wouldn't squeeze at the lower pressure!
Click to expand...

I don't trust myself enough to check the regulator back at the compressor every time I change tools, so I have a small regulator that stays with my rivet gun, and just leave the compressor set at 90psi all the time.

FP12082013A0002L.jpg
 
Hello everyone!
Thank y'all for advice.
Im happy to report that my squeezer mashes rivets as if they are made of butter. As soon as I opened the gap between dies, I'm getting pancakes (more like crepes) out of a rivet no matter what size it is. I now need to figure out the exact opening width to minimize ram's travel. Working on it...

So, to answer Tom's question about which squeezer I have, i can say "a good one, cadmium colored with a black yoke". :) I don't know who made it.

Now a question. How do you hold a squeezer? Ram travel distance is pretty long. Every single rivet I pancaked is surrounded by chewed aluminum. I cannot seem to find a static point at which to apply the sueeze. Which head of a rivet do you hit with it?
 
Squeezer

Post a photo of the chewed aluminum.
Set it too wide first so it can't over squeeze then creep up on a perfect shop head.
There's no right way to hold it or position it. Basically, whatever works.
Make sure you have the correct rivet sets in the yoke for the job.
They can go either way. Most of the time, the set for the factory head will be on the ram side and shop head die in the yoke.
 
Yuri - not sure I understand what you're saying - rivets are squeezed too much..? Not sure I understand the chewed aluminum comment - have a pic? There is a spacer under this flange, hence the gap. Other than that, do they look similar?

969b5b69a3d5c7797d086fbd179c67d7.jpg


Not sure what brand squeezer you have but mine came with a table of recommended gaps per rivet size. It's not perfect, but an excellent starting point. Eventually you will be able to eyeball common sizes - 3-3.5s. I can email a pic of the table if you'd like.
 
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localizer said:
Now a question. How do you hold a squeezer? Ram travel distance is pretty long. Every single rivet I pancaked is surrounded by chewed aluminum. I cannot seem to find a static point at which to apply the sueeze. Which head of a rivet do you hit with it?
Click to expand...

You may want to take an EAA sheet metal class before proceeding or in the least get together with an experienced builder and spend some time working on the basics. What you are taking on is very exciting, but it must be approached in a serious manner. Practicing with part that are going to end up on your plane is not wise. Have fun!
 
localizer said:
How do you hold a squeezer? Ram travel distance is pretty long. Every single rivet I pancaked is surrounded by chewed aluminum. I cannot seem to find a static point at which to apply the sueeze. Which head of a rivet do you hit with it?
Click to expand...

Assuming right handed, I usually hold the part with my left hand, squeezer in the right hand. You want the "head" of the rivet to be pressed tight against the part, so I usually have the head on the movable ram side. Then apply pressure against the head while slowly pulling the trigger with your right hand. It should smoothly tighten up if you press lightly and once you make contact with the tail of the rivet you can finish the squeeze. You want to make sure you keep the squeezer at 90deg to the work or yes you will damage the surrounding structure.

Keep backing off the ram until you don't get pancakes but instead nice muffin tail :) like you see in the picture above. Good luck, and like Jeff says practice on some scrap until you are comfortable or find a class or EAA chapter to get some help in person if needed.
 
Right. You don't "hit" a rivet with a squeezer. For starters, take out a rivet that you will want to squeeze. Just the rivet, say AN426AD3-4 (or whatever's appropriate for your practice pieces). Set the rivet on the workbench. Now grab your squeezer with the dies in it, connect it to air, and pull the trigger with nothing in it, just the squeezer by itself. If the two dies touch, open the adjustable ram (make it shorter) so that at full travel, the dies don't touch. Then open it some more, so that at full travel, the dies are apart by ALMOST the length of the rivet sitting on your workbench. You want the die gap to be a little smaller than the rivet, so that squeezing starts.

Now put the rivet in the hole of the parts you're assembling (scrap first until you get the hang of the squeezer). Set the top (non-moveable) die of the squeezer against the manufactured head of the rivet. Try to hold the squeezer as square to the part surface as possible, and slowly "feather" or gently depress the trigger of the squeezer, so that the ram gently closes. The ram will come up and ever so slightly begin to deform the rivet, and you will depress the trigger more and more until it reaches full travel and the trigger is fully depressed. The squeezer and your hand stay in the same place this way.

Remove the squeezer and close the gap between the dies just a little bit, and repeat. You want to sneak up on this setting. Soon you will have rivets that look like the photos that others posted.

You will begin to get a feel for your particular squeezer, the trigger feathering and the gap required for various rivet sizes. Then you can play tricks like holding the moveable die against the shop head and letting the non-moveable die come up to squeeze the tail of the rivet, for areas where access is an issue. You will see that the entire squeezer and the hand holding it will have to translate toward you while using this method.

Some pics of your squeezer and the "crepe" rivets with mangled aluminum would be helpful in diagnosis also.
 
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krw5927 said:
Right. You don't "hit" a rivet with a squeezer. For starters, take out a rivet that you will want to squeeze. Just the rivet, say AN426AD3-4 (or whatever's appropriate for your practice pieces). Set the rivet on the workbench. Now grab your squeezer with the dies in it, connect it to air, and pull the trigger with nothing in it, just the squeezer by itself. If the two dies touch, open the adjustable ram (make it shorter) so that at full travel, the dies don't touch. Then open it some more, so that at full travel, the dies are apart by ALMOST the length of the rivet sitting on your workbench. You want the die gap to be a little smaller than the rivet, so that squeezing starts.

Now put the rivet in the hole of the parts you're assembling (scrap first until you get the hang of the squeezer). Set the top (non-moveable) die of the squeezer against the manufactured head of the rivet. Try to hold the squeezer as square to the part surface as possible, and slowly "feather" or gently depress the trigger of the squeezer, so that the ram gently closes. The ram will come up and ever so slightly begin to deform the rivet, and you will depress the trigger more and more until it reaches full travel and the trigger is fully depressed. The squeezer and your hand stay in the same place this way.

Remove the squeezer and close the gap between the dies just a little bit, and repeat. You want to sneak up on this setting. Soon you will have rivets that look like the photos that others posted.

You will begin to get a feel for your particular squeezer, the trigger feathering and the gap required for various rivet sizes. Then you can play tricks like holding the moveable die against the shop head and letting the non-moveable die come up to squeeze the tail of the rivet, for areas where access is an issue. You will see that the entire squeezer and the hand holding it will have to translate toward you while using this method.

Some pics of your squeezer and the "crepe" rivets with mangled aluminum would be helpful in diagnosis also.
Click to expand...

+1 LOL, that IS why it is called a squeezer! You should develop the skill to locate the ram anywhere in its stroke and hold it there. It is good to do this in the ram adjustment, sometimes it is too short to rotate and fully extended it is hard to rotate. Just don't be holding it when it returns or the flats will shear bits of skin off! - - skill prevents this :rolleyes:
 
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