Converting sander/polisher to grinder

Darwins Child

Thanks.

This is about as close as PA gets to a diamond cup-grinder:
4-1/2 in. Carbide Tungsten Flat Disc-Flat | Princess Auto

I just noticed that PA has some 4.5" masonry grinding disks for $3.99, so I'll give one of them a try first-off.

I'll probably buy this grinder:
Mastercraft 4-1/2-in 6A Angle Grinder with Bo | Canadian Tire

ChaseZ

I'd be tempted to give that first linked one from PA a try. Good thing about them is if it doesn't work to your satisfaction they will return it no questions asked.

I've had a zillion of the cheapy Mastercraft and Power Fist angle grinders over the years. Mastercraft no long has lifetime warranty on them. PA as mentioned will return anything. In some cases it's worth buying a decent one but not always. Given that super fine dust you're going to subject this one too I'd get the cheapest one you can as it will have a truncated lifespan to be sure.

Darwins Child

Thanks for the advice, Chase. I appreciate it.

I contacted a Hitachi tool service center this morning, described what I proposed to do with our Hitachi sander / polisher and then went there with the tool so that the tech could more adequately advise me.

In short, my tool's max. 3400 rpm and an arbor that does not have flat spots on its side near the gearbox make it inappropriate for even occasional conversion to use as a grinder.

The good thing is that after having explained to the guy exactly what temporary task I wanted to accomplish with a grinder, he marched over to a shelf full of used tools that were for sale, picked up a grinder, handed it to me and said "here, you can borrow this until Monday". "Borrow"! Now, there's a word you don't here too often at a business nowadays. Not only that, but no deposit or credit card was required and he even refused my offer to leave my Hitachi as collateral.

To sum up, I took him up on his offer, shook his hand, walked out the door and drove to PA, where I bought a 4.5" masonry grinding disk for just over $4. So this job is going to cost $4, plus some gas to take me back and forth a couple of times to the tool service place. How's that for a happy ending?

The only possible downside is that he also said "if you break it, you've bought it, OK?" And I agreed. This means that for this job, this particular tool is going to be treated probably the best it has in its entire life.

BTW, the guy said that a grinder is one of the most useful power hand tools that one can buy, and went on to explain some of its various uses. I was impressed to the point that I might actually buy one of the things.

Darwins Child

I'd like to open up this thread to a discussion of the tasks that can be accomplished with a good grinder / cutter. I need some additional incentive to buy one.

For example, I have recently "machined" some custom-design jacking blocks for the Z using 2 x 2 aluminum bar and doing the "machining" with a manual hacksaw, a really good file and lots of blood, sweat, but no tears. How much of the work that is typically done with a hack saw can be done with a grinder? Specifically, could a sober you cut a fairly accurate 1/2" wide x 1/2" deep slot in a block of aluminum and, if so, how?

What imaginative things have you done with your grinder and what have you learned, good and bad, by your experience?

Do any of you have variable-speed grinders and, if so, what do you think of it and what advantages does it have over a fixed-speed unit? In particular, what do you think of the Makita variable speed grinders?

Thanks for any comments about your grinder ownership.