why is air hose twisting up?

[FigureLLC]

i went to do some polishing this morning with the die grinder, and the air hose kept twisting itself up. i've got industrial style QDs, so the tool is free to rotate independently of the hose. when i trigger the tool, the hose spins pretty hard. there's no torque from the tool going to the hose. the hose is straight without any twists. i've got two 3" denim buffs stacked, which i've used on the same die grinder before without the hose twisting. it doesn't happen with no tool or a small tool, just with this kinda large buff. line pressure is 100psi standby and 90-95psi triggered. anyone know the reason behind the hose twist?

[FigureLLC]

nevermind... the longer-than-necessary shank was bent and the vibration was causing it.

[mpierich]

nevermind... the longer-than-necessary shank was bent and the vibration was causing it.

Haha...did I ever tell you guys what happens when I use a 6" mandrel with an off-balance heavy 1/2" cart roll in my big electric grinder...? This was quite a thrill when it happened...

[CarWiz]

Yep, been there done that. I keep a 36" piece of 3/8" drill rod hanging on the wall as a reminder to support the loose end of stuff through the lathe headstock. Scared the bejeezus out of me. Sounded like a gun going off each time the twisted and bent piece hit the wall. At about 1200rpm, it was hitting mighty fast too. I sure am glad I was working to the right.

[FigureLLC]

thanks for posting that. that's no joke. when i was working at ge, a veteran machinist (i think somewhere around 20 years on this one machine) had a 3ft or so indicating bar chucked up in a giant vertical mill. he went to jog it around, accidentally hit "on", it spun up to the last operating setting, deformed the bar instantly, and it swung around and struck him in the head killing him.

i'll be more careful with the polishing tools. when you can hold something in your hand, it's easy to underestimate the damage it can cause.