Thread: Slow vs fast Spark grinders

Originally Posted by Big Shed

Before I do this I would like to know whether there is any advantage in getting a slow (1400RPM) spark grinder rather than the fast (2800RPM) spark grinder I am using now?

yep...the slower ones are easier to catch

Originally Posted by Ed Reiss

yep...the slower ones are easier to catch

You must be confused with girls Ed

Originally Posted by Big Shed

Before I do this I would like to know whether there is any advantage in getting a slow (1400RPM) spark grinder rather than the fast (2800RPM) spark grinder I am using now?

Is there a real difference in results between the 2?

I think that the only difference is that the slower speed will cause less heat being generated, hence you can grind longer if needed. Not really necessary if only touching up your tools.

BTW, thinking of getting the jigs as well for use with my Seppach.


Peter.

Originally Posted by Big Shed

You must be confused with girls Ed

Ha...at my age the slower the better!!

I dont belive there is any diffrence in the edge quality- but i find that its much easier to blue the edge on a 2800 grinder than it is on a 1400. I know that it doesnt matter if the edge blues just as long as i dont quench it. i also find that that the 2800 is so fast that controling the shape of the bevel etc is difficult- especially when using jigs.

The high speed grinders are very good for rapid removal and I dont really favour them. Mine is 1440 and its plenty fast enough and I use 120 grit
At 2800 on a coarse wheel [ say 80grit ], control is an issue especially if your not used to handling a grinder. If I had to use a 2800 then I would back off on my grit size, at the end of the day we are sharpening, not forming and so I dont see the need for losing tool steel on the grinder.

Heres a bit of info on grinding wheels etc
Google

Originally Posted by Ed Reiss

Ha...at my age the slower the better!!

Fast horses and slow women eh Ed

The Blue Max wheel runs a bit cooler than others cos of the honeycomb structure; with a bit of care you shouldn't be doing any bluing with HSS tools with a fast grinder, even with white or pink alox wheels.

Your best guarantee of avoiding it in any case is to dress the wheel often; when it clogs the crystals at the surface don't break down and you get friction and heat without much metal removal.

AFAIC the best combo is a cheap chinese platform on one side and BGM on the other. For scrapers etc if you only have BGMs you are prob looking at buying a platform to mount on the bar anyway.

I Fred I read Somewhere don't remember where with fast grinders, if it's for just a touch up =just bring the grinder to full speed and switch off.bring the tool and sharpen as it slows down= No blueing the tool.
Cheers Tony.

Originally Posted by rsser

AFAIC the best combo is a cheap chinese platform on one side and BGM on the other.

Blue Grass Music