Ok - here goes.
Own one - like it - good gun.
I broke two springs in one day. The spring looks like it broke from a shear impact.
I now have 4 new ones on the shelf and noticed a change in supplier.
What is the typical pressure used in these ?
I took the idea on the springs - that they might not be tempered or treated post winding or post heat treatment.
Martin
On Sat, 23 Feb 2008 20:14:33 -0600, with neither quill nor qualm, "Martin H. Eastburn" quickly quoth:
You need to learn better gun control, son. Even if you switched to a solid, screw-on chisel retainer, you'd end up splitting the end of the housing if you let the chisel get away from you that often.
HINT: Don't push the chisel against the piston and pull the trigger without something against the chisel tip. ;)
"Huh?" he queried, with a dumb look.
If they weren't heat treated, they probably would be unwinding and bending out of shape, not breaking cleanly.
I have found mine last much longer if I screw it on all they way, then back off 1/2 turn or so. That way it is not flexing just the very end of the spring.
MikeB
For best life, springs should be stress relieved after winding and forming. 500F for 30 minutes is recommended for for carbon steel springs. Try it on one of your remaining springs.
Don't I wish I were that young to be called son.
What is the typical air pressure a IR121 gun is used with ?
I start it up against work, but it goes through the work and continues to be moved to the side for more work. So it isn't Always on work. And can't be.
My concern was if I was over pressuring it and thus the hammer was throwing the chisel to hard and it beat up the spring.
Regarding the heat - process wasn't completed - never annealed ? If not crystalline like it might be soft metal.
The new ones are stronger steel. The screw on was the same pitch, but it took more force to thread it on as it also spread the spring.
The previous spare part was in a poly bag - likely bulk supply. Now the new ones - same part number - come in poly/cardboard - MADE IN USA with the plant name and state.
I suspect these will last. I suspect the previous two (gun 1st) and optional spare - were from China and not to spec.
Those are screwed on chisel retainers. I assume you mean by getting away from me is pounding air with it. Martin
Mart> On Sat, 23 Feb 2008 20:14:33 -0600, with neither quill nor qualm,
Thanks Ned -
I'll test the two broken ones - see if I can 'snap' it and then if so, I can heat that temp in two ovens - so it can be done. Then try the same test again - and see if that was the failure.
Mart> >
Almost certainly 90 psi.
I'm sorry to say I didn't understand your earlier posting.
Grant Erwin
On Sun, 24 Feb 2008 20:47:11 -0600, with neither quill nor qualm, "Martin H. Eastburn" quickly quoth:
What, you didn't hear my Foghorn Leghorn voice there? ;)
Standard air: 90psi or better, one hopes.
While that's possible, the more frequent cause is that you cut off what you're chiseling against and don't come off the trigger soon enough. That can break springs and the end of the gun itself.
Si, eez possible.
That could be the spring mfgr's building specs being smaller, too.
SAE parts for a metric body?
Precisely. That'll kill a gun quickly. A leather-gloved hand on the chisel can help mitigate that, too, but it's secondary.
You've learned to feather the trigger, oui? Trigger control is key to mastering those monsters. I hope you're not one of those poor souls who never come to realize that air is a variable speed tool. Triggers can be finessed. You'd be amazed to see how many people think they're toggle switches, either full on or full off.
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