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Lapidary Shop / Moderator, Catmandewe ( Tony ) => Miscellaneous Shop Talk => Topic started by: zurn on December 13, 2015, 02:31:57 PM

Title: bench grinder
Post by: zurn on December 13, 2015, 02:31:57 PM

here we go another newbie question
do you think its possible and plausible to convert a 6" double wheel craftsman bench grinder for use in lapidary
what made me ask

i was watching a youtube video lapidary was shaping a stone with what looked like a grinding stone like I have on my bench grinder
it was a combo machine with a saw he 1st used the saw then shaped then another machine for polishing

Title: Re: bench grinder
Post by: jakesrocks on December 13, 2015, 03:29:09 PM

A Craftsman bench grinder will spin much too fast. Lapidary wheels are made to run at 1725 RPM or slightly higher. At bench grinder speed you run a very good chance of having a lapidary wheel come apart. You don't want to see what happens to the person standing in front of that wheel. (Think frag grenade).

Title: Re: bench grinder
Post by: zurn on December 13, 2015, 06:11:37 PM

ya I saw the rpm's after I posted
oh well
ya that would be messy
thx Jake

Title: Re: bench grinder
Post by: jakesrocks on December 13, 2015, 06:35:22 PM

If you look around, you might find an older grinder with 1725 RPM's. My first lapidary grinder was an old yard sale cheapy bench grinder with the right RPM's. Had to build my own hoods & pans for it.

Title: Re: bench grinder
Post by: slabbercabber on December 14, 2015, 07:27:31 AM

Lapidary grinders should be run wet.  You wouldn't want to put water on any bench grinder.

Title: Re: bench grinder
Post by: zurn on December 15, 2015, 06:17:12 AM

I am in the market for a trim saw
as well as a lapidary grinder do you think that is possible for a $1000

Title: Re: bench grinder
Post by: slabbercabber on December 15, 2015, 07:16:36 AM

Zurn, 
Currently there are two Rocks and two Gemlap trim saws for sale on Ebay for under $200.  Complete grinding arbors with four or more wheels should sell for around $400 used.  These are as good as anything being sold new.  My personal saws include an 8" Gemlap for large preforms, a Rock's for 6" for general purpose and a Highland Park 4' for expensive stones.  The Gemlap is pretty loose cutting making a giant kerf.  Perfect for blasting through Brazilian etc.  The Rock's is very high quality on par with Highland Park but generally sells for less due to the lower name recognition.  All of these can be rebuilt easily by any one with a bench vise.
  I don't see any appropriate arbors at the moment, but with a little patience you will find them.

Title: Re: bench grinder
Post by: zurn on December 15, 2015, 09:26:08 AM

Thanks for info
I'll check them out
Tony

Title: Re: bench grinder
Post by: Larry Patrick on December 16, 2015, 05:15:00 PM

Guess that answers it for me also wanted to know about same grinder and using it. Look forward to wet grinder and saw.