Replies

1. 
   WillGeorge | Aug 08, 2009 11:52pm | #1

   Please no Tormec stories.. I have one and it has it's place.

   I only mention your reference because of the speed. I think Jet and Grizzly have one similar. A link for the Grizzzz. Hard to beat for the price.. OK so you need the accessories also.

   http://grizzly.com/products/t10010

   Old metal worker here that used high speed grinders (with liquid cooling) GREAT but... Not for the home shop.

   You did not mention what you wanted the grinder for. As in it's day-to-day use.

   For sharpening most tools I would forget a high speed grinder. Get something around 100/200 RPM and if you can get different grade wheels, all the better.

   Never had any luck with a low speed horizontal wheel grinder. Hard to see what is really going on.

2. 
   derekcohen | Aug 09, 2009 05:01am | #2

   Hi Dan

   Will makes a very good point when he asks you what you want the grinder to do. There is a difference between grinding HSS lathe chisels and HCS bench chisels and plane blades. The HSS is essentially resistant to the heat generated, while HCS is very vulnerable to the heated created (hence the advantage here of of a water-cooled machine).

   The slower the speed, the cooler the machine. Essentially, a 6" high speed machine runs at the same speed as a half-speed 8" machine. Yet the 6" if you want to save money. I have an 8" half-speed (as the hollow created is closer in size to the 10" Tormek I also use).

   The heat is also best reduced by a coarse and friable wheel. The worst offenders in this regard are the hard grey wheels. Unless you have a very light touch and are very experienced, you will burn HCS. They are designed for HSS. If you can afford the (little) extra, get the blue Norton 3X wheels. They run the coolest of the lot. Next up are the white Norton wheels. If you are simply grinding a hollow, get either a 36- or 46 grit wheel. Keep in mind that the grinder is not a sharpener, and you move from this hollow to a stone or other medium for honing. I would not go above 60 grit here (I use 46 grit). For HSS lathe chisels you would want to sharpen on the grinder as well, so the combination of 60- and 120 grit wheels is attractive. Yiou will still need to get sharper than this for some tasks.

   The next important issue is the tool rest. This can be as cheap as you like (e.g. make your own) or fairly pricy (buy a decent one). Either way, forget the rest that comes with the grinder as it is likely to be too flimsy. This feature may also sway you towards a particular machine, but I suspect that they are all horrible.

   I hear very good things about the very solid steel Wolverine Grinding Tool Rest. I wanted one but they are not available in Australia. I was using the LV rest, which is good enough (some love it and some hate it - it has a bunch of attachments that are very useful). In the end I wound up with a Tormek Bench Grinder Mounting Set BGM-100. This gives me the best of all worlds - flexibility to work with all the Tormek accessories on the half-speed grinder, plus move the blade back to the Tormek when needed. Keep in mind that I grind bench chisels, plane blades, and lathe chisels. I also have a wide range of steels in my tools, from vintage HCS to A2 to D2 and HSS.

   Here is my set up on the half-speed grinder...

   View Image

   A "look" of the rest is at: http://www.forums.woodnet.net/ubbthreads/showflat.php?Cat=&Number=4419682&page=3&view=collapsed&sb=5&o=

   Regards from Perth

   Derek

    

1. 
   WillGeorge | Aug 09, 2009 06:04am | #3

   Great reply!

3. 
   roc | Aug 09, 2009 07:14am | #4

   I suppose you saw the sharpening videos by Gary Rogowski here at FWW.

   Note the separate axle with stone wheels and a pulley with the motor out of the way vea a belt. I would do this if I were doing it over. In fact I have intended to set up this way I have just not made my self stop and do it. I would add some dust collection 'cause the white wheels make a bit more dust. Bad stuff to breath week in and week out.

   I would make up more than one axle or have several stones, strop wheels, buff wheels, emory wheels the works on one long axle with couplers along the length so don't have to slide them all off to get at a middle one.

   The motor housing gets in the way on a regular two stone bench grinder.

   The bigger the wheels the slower the motor speed needed for the same feet per-second at the surface of the stone which is what matters. Slower is better for sharpening. No precise number. Can change speed by changing one of the pulleys.

   My two cents

   roc

   Give me six hours to chop down a tree and I will spend the first four sharpening the axe. Abraham Lincoln ( 54° shaves )

   
   

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   Edited 8/9/2009 12:20 am by roc

4. 
   Senomozi | Aug 09, 2009 08:44pm | #5

   I have a low speed 6" General (http://www.general.ca/site_general/g_pictures/15-625.jpg). Came with two 3/4" wide grey stones. I replaced one with a 1" wide 80x Norton Cool Grinding Wheel. The wheel cover on my grinder is wide enough to accommodate going to a 1" wide stone without any mods necessary. I also replaced the crappy tool rest with one made by Veritas. The grinding wheel needs dressing regularly so a wheel dressing stone/tool is also a must in my opinion. All in all the "extras" add up significantly to the total setup cost, which could be an issue if you are on a really tight budget. I find this setup works well for me. I do plane irons and chisels only, no turning or carving tools.