The time it happened to me it was a shaving from machining, we figured it was lodged in a hole, and fell under the part as I loaded it onto the magnetic chuck. It was just enough that it allowed the part to shift or tip and drive itself into the wheel. That was a 1” wide, 8” diameter wheel. I can still remember seeing two pieces of wheel flying up and over each shoulder.

The other time I’m not sure the cause, I don’t recall hearing if they figured it out. It was a larger wet grinder, with a wheel that was I believe 2” wide and 12” diameter.

For those that don’t know, when ever coolant is used on a grinder, shut the coolant off, and run the wheel for another few minutes. (Was always told two minutes minimum, I tried to go 5-10 while doing other things.) This allows the water/coolant to fling back out, or off the wheel. If not, the liquid can settle to the ‘bottom’ when shut off, and can cause an out of balance situation. Sometimes enough the wheel can crack and explode.

Oh, and Tim, if no-one has shown or told you, make sure to ‘ring’ a wheel before mounting it.

Balance it on your finger or whatever is easy, and give it a light tap with something non-metallic (plastic screwdriver handle, for example), and a good wheel will ‘ring’. If it’s cracked you will hear a dull sound or even a thud. If that’s the case, destroy and toss it.


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I was running a (IIRC) Landis hydraulic grinder, about 60 years ago. The mag vice was a big DC powered vice, with the power supply on the wall next to the machine. The wheel was about 1.5x12. The project was precision drill press vice bodies. It got real exciting when the power went off. The vice body, some how, cleared the guard at the end of the table and bounced off the wall. There wasn't much left of the wheel. At the time I didn't think it bothered me that much. However, when everything was reset, and the wheel took it's first pass, I about hid under the machine. It took a while to get over that excitement. The chuck was replaced with a permanent magnet chuck real soon.

Did a quick scroll thru the video, so, this machine needs a new screw for the cross slide?

At the rate you’re going you need to retire now to have the time to do the projects you already have.

How long til we hear about ORF needing time to relax again due to impending burnout?


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It's that time of year when about half way through a normal work day you can wring the humidity/sweat from my shirt so I've been having a fair amount of downtime outside of work and not overdoing it in the 95 plus degree heat.

Getting bored? Yes. Burnt out? No.

It does need a new cross feed screw. The part the arbor is mounted in moves forward and back. Table only side to side. Already have the broken screw removed.

Now im looking for a 10 tpi acme thread carbide cutter and a matching holder.

Now im looking for a 10 tpi acme thread carbide cutter and a matching holder.[/QUOTE]


ORF,

Why go to the expense of a carbide cutter for a one off job?

You won’t be running it at high speed when you do the screw cutting, a hand ground HSS tool will do the job fine.


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ORF,

Why go to the expense of a carbide cutter for a one off job?

You won’t be running it at high speed when you do the screw cutting, a hand ground HSS tool will do the job fine.


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True, but all the cool kids use Carbide......

Seriously, with all the grinders ORF has, a simple profile gage - even one cut from a cereal box, and 10$ worth of HSS would do all the acme threading ORF would do in his lifetime. And he'd learn a new skill....

There is a time and place for HSS, and this is one of them.

The price for the holder for the carbide acme thread tool would be impressive.

+1. Unless you plan on manufacturing them for others.

Heck, if you really want carbide, just get some 1/2” square brazed carbide cutting tools and grind your own.


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Or, buy a length of acme threaded rod and just machine ends to suit.


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That was my thoughts at the start of the lead screw discussion. I expect he has plenty of other things to do beside making your own.