Bench grinder recommendation

[Phil Mueller]

Looking to add a bench grinder to do three things; major rehab of old plane and chisels (primary bevel work), regrind primary bevels (example 25 degrees to 20 degrees), and hollow grind. I’ll finish the honing, etc., on stones.

Sounds like variable speed, or slow speed is the way to go, and 8”. There are a lot of these available from JET to all the standard big box brands. Just looking for some real world experience.

Would also be interested in the type of wheel medium(s) I should get to work 01, A2, PMV11.

Would really prefer not to invest in a Tormek or other sharpening system. Just looking to get the grunt work done a bit faster. Suggestions of grinder brands and wheel medium is much appreciated!
Phil

[Pat Barry]

I don't think there is much practical difference between a 6 inch grinder and an 8 inch grinder as the depth of cut is virtually the same for grinding a bevel on a chisel or plane blade. Also, at the same rpm, the 6 inch grinder is running slower in terms of the speed at the grinding surface as compared to the 8 inch wheel.

[Mike Null]

I would be concerned with the RPM. I have Craftsman that's over 30 years old. It does most of what I need, particularly when I want to grind something away. But I am always uncomfortable using it for sharpening at 3400 rpm. That said, I believe George Wilson has been using the same grinder for years for all his shop work.

[Brian Holcombe]

I picked up a used Baldor grinder for not much, it has 6" wheels. I was able to put a CBN on it and retain the housings and guard.

[Derek Cohen]

Phil, a link to my article on CBN wheels and sharpening, written a few years ago now...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html

8" half speed 1 hp grinder with 80- and 180 grit CBN wheels, Tormek BGM-100 tool rests ...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp_html_5c5d41f4.jpg


Regards from Perth

Derek

[Bruce Haugen]

I have a Delta 6” grinder, 3750 rpm, with a 100 grit white wheel. I have no problems grinding any of my tools. I use light pressure, take light cuts and monitor the temp of the tool with my fingers.

Having said that, I wish I had an 8” grinder, but not for the usual reasons. The problem is that the motor on this grinder is larger than the wheel. That limits the width of any tool it can sharpen. It works fine for plane irons and chisel or iron up to 4”, but it’s impossible to rig up a jig to sharpen planer or jointer blades. Maybe there are different configurations of motor that would solve this problem, but I haven’t seen any.

[Jeff Ranck]

This is one of those things that you don't have to stress too much over. Almost any grinder will do, but it is easier not to burn tools on a slow speed grinder. You don't want one with so much runout that it can't be compensated for. An old Baldor like Brian uses is great. But the slow speed grinders from Rinkon or some other manufacturer are also just fine. I've used many and currently have some brand that Woodcraft used to sell before they picked up Rinkon. It has been fine.

How you set it up and how you use it is more important than the type of grinder it is.

Jeff.

[Mike Walsh]

I've had the low speed Rikon grinder for a few years and it works well for any sharpening needs that i've had

[Jeff Heath]

Phil, a link to my article on CBN wheels and sharpening, written a few years ago now...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp.html

8" half speed 1 hp grinder with 80- and 180 grit CBN wheels, Tormek BGM-100 tool rests ...

http://www.inthewoodshop.com/WoodworkTechniques/UltimateGrindingSharpeningSetUp_html_5c5d41f4.jpg


Regards from Perth

Derek



Derek

Do those CBN wheels dissipate heat as well as everybody "says" they do. I'd like to hear your opinions on that vs. the typical grinding stone/wheel. My 4 grinders are all 10", set up with different wire wheels and stones for different materials. I just picked up an old 1/2 speed Hisey Wolf, and am thinking about putting a CBN wheel on each side of different grits, like your setup, for my turning tools and gouges. I bought the same Tormek setup, but haven't had time to rig it all yet.

Thanks for any input down this path.

[Carlos Alvarez]

I have a Delta variable speed and like it a lot. We use it for sharpening as well as other general duties. The welding area has a full-speed grinder also, but I use the variable for some cleanup jobs when higher speed is undesirable. It's been fine for probably ten years.

[Derek Cohen]

Do those CBN wheels dissipate heat as well as everybody "says" they do. I'd like to hear your opinions on that vs. the typical grinding stone/wheel. My 4 grinders are all 10", set up with different wire wheels and stones for different materials. I just picked up an old 1/2 speed Hisey Wolf, and am thinking about putting a CBN wheel on each side of different grits, like your setup, for my turning tools and gouges. I bought the same Tormek setup, but haven't had time to rig it all yet.

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

[Todd Stock]

Ditto...things stay cool, and grinding is a predictable process with jigs permanently set due to the stability in wheel diameter. We run a low speed grinder, if for no other reason than many CBN wheels cap out at 3000 RPM...the Rikon 1/2 hp is enough to handle a 1" CBN wheel. For a shop with student luthiers, the additional safety seen with CBN versus SG or conventional wheels is one less thing to worry about.

[Hasin Haroon]

If you're willing to go for used items, you can often find a good deal on a tormek or a veritas mk II. I got my mk II with a couple extra holders and platters for $100 on Kijiji, which is the only reason I have it or I would've gone with a cheaper grinder like yourself. If you do go with a grinder CBN wheels have been highly recommended by everyone I know that upgraded to them, but they definitely are not cheap.

[Jeff Heath]

Hi Jeff

The CBN wheels do a great job of keeping the blade cool.

Regards from Perth

Derek

Thanks, Derek: I appreciate the feedback. I'm going to set a grinder up with one of these, probably the 180 grit to start.

[Frederick Skelly]

I've had the low speed Rikon grinder ........ works well for any sharpening needs that i've had

Me too. Put a cbn wheel on it and Im a happy camper.

[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 (http://woodcentral.com/articles/powertools/articles_775.shtml)

[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..