9 inch angle grinder- direction of rotation

[terry.shitcrumbs]

Hi. I have an el cheapo 9 inch angle grinder that I bought years ago. The b rand is Kinzo and it has a reversible handle (i.e. the handle rotates about the long axis of the machine, to give left handed or right handed operatio n. This means that unless the shield position is rotated at the same time a s the handle, thereby requiring the machine body to be rotated, end-over-en d, for use, the disc's direction of travel against the workpiece is reverse d. If the direction of travel is reversed in this way, the effect is to cau se the machine to pull away from the user for one particular handedness and to push toward the user with the other handedness. I'm sure you get my dri ft.

My question is: is there a correct/safe direction of travel for a grinding disc against a workpiece? More particularly, I am referring to grinding whe re the user holds the machine directly in line with the direction of cuttin g? Having played around a bit, today, it feels far more unsettling when the grinder occasionally kicks/grabs and pushes toward you, rather than pullin g away from you. When testing it, I held it offset, to one side, so that a sudden or violent kick wouldn't send it into my body.

Thanks.

Terry.

[newshound]

I think that both 9 inch and 110-125 mm machines are normally made for right handers. By which I mean, with the machine body in the right hand and the disk down, the removable handle is to the left, and the disk is rotating clockwise from that viewing direction. The disk reviews anticlockwise when viewed from the nut direction, which is why a right handed nut "tightens" in use. So, when cutting in the normal way, the disk pulls the machine away from you. If you think about it, this is the right way for the feedback to be safe. You apply force to make the cut, if the machine grabs it tends to reduce your applied force. With the disk turning in the other direction, "grab" tends to make the force that you are applying increase. So the grab increases, etc.

Presumably left-handers develop a safer technique to compensate, or perhaps they still hold the body in the right hand and the handle in the left.

[David Lang]

I think you have that spot on. Also the dust & sparks are going away from you, not directly at you.

[Brian Gaff]

Seems a little odd that it cannot be set for left handers. Assuming the discs are not direction specific, it surely should be easy enough th make the motor go either way and haave a locking fixing rather than just a one direction nut. I don't like angle grinders myself even when I could see they were scary things showering high velocity muck and sparks in all directions and very very noisy. By the time you got googles and ear protectors on, you had probably forgotten what you were doing anyway. Brian

[Tim Lamb]

In message , David Lang writes

Huh! I stopped buying man made fibre overalls after several fires in a delicate region. The guard is usually set to keep the sparks out of your face.

[GB]

I really love angle grinders. It's something about the sheer brutality of the things. Here I stand, a weakling, barely able to lift my cheapo

9" angle grinder, and suddenly there's amazing power at my fingertips! :)

"showering high velocity muck and sparks in all directions and very very noisy."

All part of the fun. My main concern is a disc fragmenting, or setting fire to my house, but so far no problem.

[newshound]

+!! DAMHIK