Page 1 of 2

Question about sharpening lathe chisels

Posted: Sun Feb 28, 2010 1:15 am
by heathicus
I recently bought a cheap bench grinder for sharpening my lathe chisels. I visited my dad today and we built a stand for it. Dad is also going to fabricate a "Wolverine" style sharpening jig for me. My question is, what kind of grinding wheel should I get? The two that came with the grinder seem very course. I have the standard Shopsmith set of chisels.

Posted: Sun Feb 28, 2010 7:53 am
by mickyd
I'll let others weigh in on the best grit wheel.

If you haven't already, make sure you true up your grinding wheel with a wheel dresser. This will make the wheels working surface concentric and cut down on vibration. Also, you've probably noticed that the grinders tool rest is grossly inadequate for precision sharpening. A redo will probably be needed to get good results. I was looking at this Veritas version.

Posted: Sun Feb 28, 2010 8:39 am
by mbcabinetmaker
Heath

I hope you got a slow speed grinder. Around 1725 rpm apposed to 3450. The link below is to a Woodcraft sight. The 120 grit stones work well for lathe chisels just remember to grind slowly to reduce heat build up.

http://www.woodcraft.com/Family/2000216 ... heels.aspx

Posted: Sun Feb 28, 2010 10:56 am
by wannabewoodworker
I have been drooling over this sharpener for some time now. The only reason I do not have one yet is the damn steep price for the sharpener. The basic machine is really expensive but then you have to buy all of the jigs for sharpening different tools. But it seems to be the BEST one on the market that I can find.

http://www.tormek.com/en/

Image

The other option is to get one of these. The Worksharp WS3000 or WS2000 will do most of the shop sharpening tasks you will need to do with chisels and it won't leave a cavernous hole in your pocket.

http://www.worksharptools.com/

Image

Posted: Sun Feb 28, 2010 11:27 am
by beeg
The 60 grit works well for reshaping or badly dull tools. Just remember to use a light touch when grinding.

Posted: Sun Feb 28, 2010 11:57 am
by heathicus
I wasn't lucky enough to get the Work Sharp 3000 when Sears accidentally had it on sale for $20 and the $200 full retail price is still way out of my price range right now. But $35 for the grinder, plus a decent wheel, and a home made jig is more affordable. I could see myself buying the Work Sharp 3000 at some point in the future, but no matter how good the Tormek system is, I can't see it being worth that kind of expense.

The speed on my grinder is 3450. I've read several sharpening guides that recommend this speed (although I've also read others that said 1725), but they didn't say much about the actual wheel. With a faster speed, should I use a higher grit? 60 grit was recommended, but at 3450, should I go up to 100 or 150 grit? Are these wheels at Rockler suitable? They're a little less expensive than the ones at Woodcraft and I think Rockler still has free shipping right now.
http://www.rockler.com/product.cfm?page=10088

Mike, you're right about the tool rests on this grinder. They are a joke. Part of the Wolverine Sharpening Jig system my dad is going to replicate is a much better tool rest.

Image

Posted: Sun Feb 28, 2010 12:35 pm
by shipwright
That's a decent replica Heath. I have that system and it is a dream. I go back and forth to the grinder often while turning to keep a perfect edge. Just a light pass every few minutes. It only takes the weight of the chisel, no pressure. This system makes it very easy to return like this and be set up exactly. You'll love it too.

Paul M

Posted: Sun Feb 28, 2010 6:01 pm
by beeg
Heath, I'd say go with a 60 and 100 grit wheel. With the higher grits, I think ya get more heat build up.

Posted: Mon Mar 01, 2010 8:44 am
by rdubbs
Hi,

I'd like to respectfully add my thoughts to this thread. I agree about most of what has been said. Gray wheels are too coarse for any but initial grinding, so you're better off to stick with white, blue or pink for most tool sharpening.

The WorkSharp is a wonderful maching, but as useful for lathe tools as it is for bench chisels, plane blades, and curved carving tools. It is designed to sharpen only constant-bevel curved tools, and it has no facility to be sure that you keep the same bevel from one sharpening to the next on curved tools. It is designed so that the abrasive either moves away from, or at right angles to the edge, so it is very difficult to sharpen a contenential/fingernail grind bowl or spindle gouge with it as you really need to face an edge into the abrasive as the bevel changes.

The mounting that Heath shows for his granders is fine for constant-bevel grinding, but if you plan to use the Vari-Angle attachment for contenential/fingernail grinds you will find that you need to mount the grinder itself much closer to the front edge of your bench because you need to swing the tool handel pretty close to the front plane of the wheel.

OneWay designed the Wolverene jig for use with a high-speed (3450 rpm) grinder. Lots of folks use a slow-speed (1725 rpm) grinder, myself included, but it is not required.

Posted: Mon Mar 01, 2010 9:30 am
by efmaron
I noticed while reading this thread that nobody said anything about stroping. I do not do any turning but I do a lot of carving and strop my knives and chisels every few minutes while working, the only time I resharpen with the grinder is if the cutting edge gets nicked. Maybe turning chisels are different but it may help to strop more and grind less.