Thread: Dressing Grinding Wheels

I'm a grinding novice, so I need some help.

I just fitted a 6" Alum Oxide wheel to my grinder. But when I tried to use it, my tools bounced on it something shocking. I was surprised to find the wheel didn't run true - there was a non-concentric play of about 1mm. I immediately thought that my spindle was bent, but when I took the wheel off and measured the spindle, it was fine, so it must have been the wheel. So I put the wheel back on, and about 45 seconds with a diamond dresser soon had the wheel running true. But I didn't know if this was normal, so I read some threads here.

Since I'm not an experienced grinder, I've got a bunch of questions:

Q1) From the threads here, it seems that it IS normal for new wheels to be non-concentric and to require dressing so tools don't chatter. Is this what everyone finds?

Q2) I read this thread, and I didn't understand 's post about using the arrow. Is he saying that if the spindle isn't turning true, a non-concentric wheel can be used to cancel most of thew wobble, and that the final amount of dressing required will thus be minimised?

Q3) My grinder has a 2 speed motor (750/2000rpm). Which speed should I use for Alox wheels? Is a slower speed better to reduce heat?

Q4) I used one of those T-shaped diamond dressers (Timbecon, $49). How lomg will this last me? Forever?

Q5) I've also got an old 4" wheel that's labelled "for grinding carbide, medium grit HC45". It's a very smooth wheel rated for 6210rpm. Does this mean it is meant for Tungsten Carbide, and that I should NOT use it on steel?

Thanks,
JG