Bench grinder coming loose

[SteveC]

Prompted by this post in the  Tool Junkie thread, I bought one of those cheapish bench grinders. Pcolbeck very kindly answered PMs about setting it up.
I've not had much chance to use it until this afternoon. After about ten minutes or so, the grinder pulled the mounting screws from the piece of wood I'd attached it to, which makes it rather unusable at the moment.
I obviously didn't chose suitable screws, or piece of wood, or both.
Any suggestions?

[Jurek]

Bolts going through the bench, fastened with Nylock nuts and washers.

[robgul]

I have a couple of bench grinders - both cheapies but they do the job - one has 2 grindstone wheels, the other has a cloth mop and a fine brass wire brush (I do have a couple of other mops) - the polisher has the guards and tools rests removed to be able to use the mops.

Each machine is mounted on a thick piece of wood slightly bigger that its footprint - fixed with bolts through the wood.  Under the wood I have another piece of the same wood about 3" wide and the length of the footprint that's fixed at right angles (i.e. it's L-shaped if you look from one end) - fixed with heavy duty coach-screws.   The machines are stored under the bench and when in use a machine is clamped into a bench vice using the 3" wide strip in the jaws.  That holds the machine firmly and safely.
If that doesn't make sense I'll take a picture.    Just using screws to fix one of these machines to a bench isn't clever - as suggested it needs to be bolted through the top of a substantial bench - the downside is that it takes bench space - hence my storage/use in the vice solution.

[hatler]

I have a couple of bench grinders - both cheapies but they do the job - one has 2 grindstone wheels, the other has a cloth mop and a fine brass wire brush (I do have a couple of other mops) - the polisher has the guards and tools rests removed to be able to use the mops.

Each machine is mounted on a thick piece of wood slightly bigger that its footprint - fixed with bolts through the wood.  Under the wood I have another piece of the same wood about 3" wide and the length of the footprint that's fixed at right angles (i.e. it's L-shaped if you look from one end) - fixed with heavy duty coach-screws.   The machines are stored under the bench and when in use a machine is clamped into a bench vice using the 3" wide strip in the jaws.  That holds the machine firmly and safely.
If that doesn't make sense I'll take a picture.    Just using screws to fix one of these machines to a bench isn't clever - as suggested it needs to be bolted through the top of a substantial bench - the downside is that it takes bench space - hence my storage/use in the vice solution.

Oooo. That's cunning. I've loaned my late-father's bench grinder on on the basis I hadn't got bench room for it (on the assumption it would have to be bolted down).

[pcolbeck]

As Robgul says either bolt it to a bench or bolt it to a piece of wood and clamp the wood to a bench. Tried screwing mine down and it ripped the screws out.

[robgul]

The other thing to watch out for with cheap/basic grinders is the speed and power - you need to let the wheels get up to speed before you start working on anything . . . and using too much pressure can actually stop the wheels*

* I used to use the grindstone wheels to "sand" the odd piece of wood before I bought proper disc/belt sander - very easy to stop the wheels turning!

In the same grinding/polishing vein another useful option is fitting a mop that's like a green scourer pad to an electric drill for some polishing needs (the green mop works better in a drill press if you have one, running at slow speed)

[SteveC]

Thank everyone.
Looks like bolts instead of screws is the next thing to try.
May have to wait as I need to get some gardening done today.