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Got a slight problem. I need to swap the grinding disc on my 230mm grinder as the disc is heading towards half the diameter it was when I started with it (I really should replace them earlier) but anyway, the threaded circular bolt at the bottom refuses to budge. Anyone got any tips for getting it off?
Use a pair of mole grips on the rear nut, to stop it from turning, and use a small punch on one of the holes the tool locks into, and a hammer, the shock as you hit it to undo it will loosen it free.
They have a habit of tightening themselves up.
John
Is it a left hand thread? some times these things can cause problems!
It isnt a left handed tread. Normal its a M14*2 .
Stop the shaft rotating ...spanner on the two flats under the cutting disc ..... grasp the worn disc with a rag and rotate ccw.
ps...Sometimes there is a lock button on the gearbox ....this negates the need for a spanner on the shaft.
Every angle grinder I have used has a lock button, it is fitted as standard isnt it?
Trev
Is there anything you dont know woody!?:)
My grinder uses a lock button in the gearbox. I press it and then use a twin pronged spanner to try and remove the nut and even after hitting it a few times with a hammer it still wont budge.
Guess i will just have to keep trying
In my experience when discs tighten up if you rely on the locking pin, the use of a hammer will do one of two things, either break the pin, or break the ali casing around it.
Use the molegrips to stop this happening.
You should be able to use a small punch like i suggested at 45 degrees to the hole.
I had nearly a legal battle with Machine Mart when i took back a grinder as i couldnt get a disc off, and they suggested i had abused it !!!
It wont be a left hand thread.
Good luck.
JOhn
If all else fails TACK weld a steel bar to the nut and really thwack it!
Then grind the weld off ..... Umm ...assuming you have another angle grinder.
Or you could be an animal .. just hit the disc edge with your hammer .... at a tangent to and in the same plane as your disc.... you should eventually make a nice nick in the edge that your hammer can really impinge on.
Dan ...Ive been in engineering and related trades ... as have many others on here ...for a long time.
As John says you will run the risk of breaking something if you use to much abuse.
Theres an Art to gentle persuassion.:)
(Message edited by woody on September 19, 2007)
This may sound daft but if you are holding the lock-button and grinder in your hand and tapping the spanner, most of the impact is lost.
Try holding the body of the grinder in a vice and using an extension on the pin spanner.
If that fails you will have to wreck the disc as Woody suggests.
Trev
How many roboteers does it take to change a grinding disc ??? LOL :)
JOhn
49 posts to go until the magic 1000, do i get a prize ?
Think i may have to go down the weld a bar onto it option.
I have had this problem before and ended up taking the disc to bits with another grinder before being able to get it off. Just wanted to know if anyone had any solutions. I think I will put some grease on the nut before putting on a new disc to stop it seizing on completely.
I nackered the pin on another grinder before and it just popped out so I used what ever would fit in the hole to hold it when taking off a disc. Far better than using a pressure button as it stayed in place and didnt need you to hold it there constantly.
Trevor, I am pinning the grinder against the ground and wacking the nut spanner with a hammer but its just bending the prongs on it.
John Im already over the 1000 mark and i didnt get a prize. Might make some random posts on one of the fanfic boards and see if I get a prize at 2000 :)
Have you give the thread a squirt of WD 40 and leaving it to soak ?. Sometimes theres muck on the thread and this helps break it up. Might make the bit of differance you need.
Another one is to use oxy gear to gently warm the nut, but not the bolt to a nice cherry. Then try to undo it before it cools off. Dont burn yourself !!!!