Pneumatic squeezer does not work on rivets

localizer · #1 04-22-2015, 02:45 PM

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

akarmy · #2 04-22-2015, 03:01 PM

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.

FredMagare · #3 04-22-2015, 03:05 PM

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.

wirejock · #4 04-22-2015, 03:15 PM

Quote:

Originally Posted by FredMagare

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.

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.

Loman · #5 04-22-2015, 03:16 PM

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.

localizer · #6 04-22-2015, 03:30 PM

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.

TS Flightlines · #7 04-22-2015, 03:34 PM

this may sound stupid---but WHICH pneumatic squeezer do you have?
Tom

ERushing · #8 04-22-2015, 03:38 PM

Note that Avery sells low-profile sets that can give you a bit more at the end of the stroke.

spark68 · #9 04-22-2015, 07:45 PM

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.

Dan Langhout · #10 04-22-2015, 08:04 PM

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!