Bench grinder recommendation

[Tom Bender]

Trouble with motors in this hp range is that the cheapest to manufacture is 3600 rpm, so that's what most are. (except for Derek who has 50 cycle power so 3000 rpm). Variable speed can help but the turndown is only effective to around 2500 rpm. You want one that runs at 1800 rpm or if bigger than 10" you may find a 900 rpm machine. Variable speed from there would be an excellent find.

[Phil Mueller]

Thanks all! Appreciate the input. If I understand, it sounds like a full speed 6” is about the same as a low speed 8”? I like the idea of a variable speed unit...would allow me to do other tasks in addition to sharpening. Sounds like the CBN wheels are the way to go...I am looking for low mess here and minimal maintenance. Given the reviews of new, some seem to recommend guide upgrades. Checked around my local Craigslist. Nothing of interest at the moment. Going new, could be into this for $500 or so.

I’ll have to think on this a bit.

[Frederick Skelly]

Hey Phil, in case it helps - woodcraft has the RIKON80-805 (Item 158512) 8in Slow Speed Grinder on sale for $118.99. I have one. It's good enough for what I do. YMMV, though.

Fred

[Patrick Chase]

Hey Phil, in case it helps - woodcraft has the RIKON80-805 (Item 158512) 8in Slow Speed Grinder on sale for $118.99. I have one. It's good enough for what I do. YMMV, though.

Fred

That Rikon's big brother (80-808 IIRC) is a great grinder for heavy CBN wheels. It's still low-speed, but has double the power and a more effective brake to slow the wheels down when off. It also has very substantial wheel flanges that help with balancing traditional wheels. I have two of them :-).

[Phil Mueller]

Thanks Fred! I think that is the way I will go, or Patrick, your suggestion of the big brother. I must say big brother is a beast...54lbs. Not exactly portable, but probably time I figure out some kind of sharpening station in my small space. Hmmm, since it will be fairly dust free, maybe my bride will be ok with it in the spare bedroom...not!

[Phil Mueller]

Well, I was next door helping out my elderly neighbor with a few things, and he said they would be moving soon. Wanting to know if I needed any shop stuff. I jokingly said I was in the market for a grinder and he replied “I got one for you”.

It’s a 6” Thor...probably about 50+ years old. It’s 3600 rpm IIRC. Not exactly what I was looking for, but free is free. It was under a bunch of stuff, so I don’t have it yet. Anyone have any experience with this old brand grinder? I figure since it’s basically zero effort to get it and plug it in, it’s worth taking. We’ll see...maybe get it this weekend.

[john zulu]

Hi Jeff

The CBN wheels do a great job of keeping the blade cool. It is possible to still burn the steel if you hold it too long and press too hard, however the CBN is an order of magnitude better at preventing this. In general, my blades take a few seconds to grind, and rarely come off the wheel more than luke warm.

What is also important is that the CBN wheel does not wear. This means that the grit remains clean and sharp, and the hollow is smooth and even. This speeds up honing. You can grind to the edge of a blade more safely. And that speeds up honing as well.

I was talking to a professional turner last night. He uses a 180 grit CBN wheel for all his sharpening. Straight off the wheel. Nothing else. He also has a Tormek with a 10" CBN wheel, and uses it dry.

Regards from Perth

Derek

@Derek How much did you pay for the CBN wheel? Over in Malaysia is it very expensive.

[Bruce Haugen]

Well, I was next door helping out my elderly neighbor with a few things, and he said they would be moving soon. Wanting to know if I needed any shop stuff. I jokingly said I was in the market for a grinder and he replied “I got one for you”.

It’s a 6” Thor...probably about 50+ years old. It’s 3600 rpm IIRC. Not exactly what I was looking for, but free is free. It was under a bunch of stuff, so I don’t have it yet. Anyone have any experience with this old brand grinder? I figure since it’s basically zero effort to get it and plug it in, it’s worth taking. We’ll see...maybe get it this weekend.

Of course you can make it work. That’s the grinder and size I have, and while I would like a larger wheel, this combo has worked for me for more than 30 years. Read this article

[Brandon Speaks]

I have a Rikon 1/2 hp low speed. If I were to buy it over again I would get the 1 hp instead but this one if fine and not worth changing. The wheels it came with are also just fine for me. When it comes time to replace I will likely get CBN, depends on what I am doing and what the budget is at that time. Been thinking about grabbing a cheapo 6in full speed for lawnmower blades and such.

[James Pallas]

Well, I was next door helping out my elderly neighbor with a few things, and he said they would be moving soon. Wanting to know if I needed any shop stuff. I jokingly said I was in the market for a grinder and he replied “I got one for you”.

It’s a 6” Thor...probably about 50+ years old. It’s 3600 rpm IIRC. Not exactly what I was looking for, but free is free. It was under a bunch of stuff, so I don’t have it yet. Anyone have any experience with this old brand grinder? I figure since it’s basically zero effort to get it and plug it in, it’s worth taking. We’ll see...maybe get it this weekend.

Here is mine. 1/4 hp 3600 rpm branded Ingersoll Rand, Baldor motor. Runs smooth after 40 years. Does everything I need as far as woodworking goes. I think you will be just fine with your free Thor. They made a good bit of industrial stuff, valve grinders and such.
Jim

[Patrick Chase]

It’s a 6” Thor...probably about 50+ years old. It’s 3600 rpm IIRC. Not exactly what I was looking for, but free is free. It was under a bunch of stuff, so I don’t have it yet. Anyone have any experience with this old brand grinder? I figure since it’s basically zero effort to get it and plug it in, it’s worth taking. We’ll see...maybe get it this weekend.

Grinders are fundamentally incredibly simple devices, consisting as they do of a motor with bearings and shaft extensions on both ends. As long as the motor is good and the shaft turns true it's going to work fine. I'd honestly take a 50 y/o grinder over the vast majority of what gets produced today, particularly if I were going to stick heavier-than-normal wheels on it (which may place high demands on the bearings). You have to spend a fair amount now to get what would have been considered routine then.

Surface speed (not rpm) is what matters for tool burning, so a 6" 3600 rpm grinder is midway between "half" and "full" speed 8" grinders. No problem there either IMO.

[Christopher Charles]

Yep. I've got the woodcraft 'slow speed' with white wheels that I paid ~$100 for ten years ago. Have felt no real need for anything else, though Derek's articles always get me itching

Joel at TFWW had an article in FWW a while back on free hand grinding using crowned wheels. Works great.

Good luck, sounds like you're in business.

[Jerry Olexa]

Simple grinders do their job and last FOREVER..I added a slow speed 8" few years ago with good results.Of course, my TORMEK runs at very SLOW speed with virtually no risk of injury..