Angle grinder question

if nut on angle grinder is std right hand thread does that mean disc turns anti-clockwise?

Not on the 3 grinders that I have.

Depends if you are looking from the nut side or the top of the grinder.

Anti clock looking from the nut side, clockwise from above

Most have an arrow on the body somewhere to indicate direction

If you look at the nut side it goes anti-clockwise and from the gearbox side it will go clockwise, the nut should tend to tighten if you hold it still but I wouldn't use my fingers to test it. If you watch it coast down to stop it should be possible to see. When using the machine it will be obvious which way it is going. If your machine has been reversed it will be the nut that goes into orbit and the disc that chases you round the workshop. If you are outside then you will need a new nut and disc as you will probably never see either again.

Mike

Edited By Mike Poole on 17/02/2017 19:38:54

Most of these machines have motors where the direction of rotation is not so easily reversed. Much like an automotive starter motor in that it does not care what polarity.

They will work on DC current equally well as on AC, by the way - but I would prefer a 240V shock in preference to DC, I think!

Looking at the front of the grinder there is a left-hand and a right-hand wheel, and both turn "towards" you at the top.

Looking end on, the left-hand end has a left-hand nut and turns clockwise, the right-hand end has a right-hand nut and turns anticlockwise.

I remember a company that made woodcarving tools (Ashley Iles IIRC) used to specialise in rebuilding grinders so that they ran "the other way round" for the tool sharpening wheels they used (a rubber bonded wheel with embedded grit and a honing wheel). The motor wasn't reversed but the "bodywork" was rebuilt the wrong way round. The direction of turning was clearly indicated on the wheel guards or body. They used Rexon grinders. Carving tools are better sharpened with the wheel turning away from the tool.

Hi Robbo, all the angle grinders that I've ever seen only have one wheel/disc, which when you are using it rotates in a clockwise direction when viewed from the users normal point of view and have a right hand thread to hold the wheel in place. I think you must be talking about a two wheel bench grinder.

Regards Nick.

If you hold the angle grinder as if you are cutting off a horizontal bar, the front of the wheel is moving downwards, the sparks are going away from you. The nut has a right hand thread, same as a the right hand wheel on bench grinder and for the same reason. Dave

Smith and Arrow 1mm cutting discs are directional , they have an direction arrow but the info on the disc then cant be read once its fitted , as the guard hides it...

Sorry, one of the other posts led me to believe this was about bench grinders

thanks for replies.

all my grinders are in storage since lost workshop so couldn't look.

was looking at article in MEW about fitting drill chuck to bench grinder and brain started thinking about it.

.

If you are thinking of fitting a drill chuch to an angle grinder

... Please reconsider.

The rotational speed is much higher than typical bench grinder.

Unless you could safely slow the machine right down [which is doubtful]

... it wpould be an 'an accident waiting to happen'.

MichaelG.

I fitted a jacobs chuck to an angle grinder so that I could drive the small diameter grinding points and bobs up to about a inch in diameter,does not work very well ,the chuck holds the small wire brushes tight ,the rattle effect on the sides of the grinding points soon loosens the chuck,,I was then given a windy drill with a collet which takes 1/4 and 6mm grinding points ,I soon gave this up as my compressor could not keep up with the drill,so the collet was adapted to fit the angle grinder and has worked well for the last 15 years,I used a 4 inch angle grinder as these run slightly faster than 4 1/2 inch grinders,it gets a a lot of usage when removing rust and debris from tight corners and crevices in old stationary engines.

Noting Nigel's evidently successful practical experience ...

I shall refrain from further comment, and will follow the discussion from a safe distance.

MichaelG.

I always thought there was two nuts on an angle grinder, one holding the grinding disc and one holding the grinder.

The simple answer is yes. Angle grinder rotates in opposite direction as thread pitch. It is general rule for all nut clamped tooling.

All universal motors can run in both direction (theoretically) - you need to change polarity of rotor, However most of the motors are designed only in one direction (to reduce wear brushes are placed out of the shaft axis ), opposite direction run will cause huge brush wear which will probably lead to failure.

Only motors with brushes aligned with shaft axis can run in both direction.

regards

martin

Reminds me of the time I went to ALDI,S to buy an angle grinder for a friend.While I was checking to see that the box was sealed,another old guy came drifting along,picking up everything,buying nothing [you,ve met them !]

Picked up one of the boxes,opened it,pulled out all the bits and said"That looks a handy thing to have" I said,"it is,if you have the work for it" Next he said "I think I,ll buy one myself,what,s it for?"

I could not believe my ears ! I said "if you dont know what it is,leave it alone,it,s not a toy".

Maybe that,s why we need the H/SE !

Larry

Remember "Where ignorance is bliss, t'is folly to be wise"

You should have asked for his name and address so that you can stay well away!

Possibly related to the chap who suggested WELDING Imperial fittings on to continental bottles of Oxygen and Acetylene when bottles were in short supply in UK, some years ago! It really happened, in my employers company!

Thankfully, he was dissuaded from doing this.

Howard

I have seen chucks for angle grinders advetised here in NZ.

Ian S C