AX SHARPENING WITH POWER TOOLS

Hollow grinds will stick compared to flat or convex. Their deflection increases the further into the bevel you get. On a wheel that large it's at least fairly shallow.
 
Hollow grinds will stick compared to flat or convex. Their deflection increases the further into the bevel you get. On a wheel that large it's at least fairly shallow.
I thought we were arguing power tools vs handiwork? You're more than welcome to fancifully grind off as much steel as you want with all manner of grandiose ideas that require very little effort. Now go ahead and try that with a file or a stone.
One tool will merely become floor filings whereas the other won't be ruined when the next guy takes a shine to it.
 
I thought we were arguing power tools vs handiwork? You're more than welcome to fancifully grind off as much steel as you want with all manner of grandiose ideas that require very little effort. Now go ahead and try that with a file or a stone.
One tool will merely become floor filings whereas the other won't be ruined when the next guy takes a shine to it.

Lol whut? What are you even saying here? All I said was that using a jig like that will put a hollow grind on your bit, and that I was curious if the intended wheel diameter had been given for the jig since all the dimensions shown on it were kind of meaningless without knowing the right wheel diameter.

Anyhow, here's some info from the 1960 textbook "The Farm Shop" detailing good technique for a dry motorized grinding wheel.

16999151_10212017477220690_1011758067526437816_n.jpg


16996518_10212017478260716_4088389811803097796_n.jpg
 
Apt summary DbH. During my working days as a carpentry contractor I always kept a series of 'hack' chisels (in the 1980s these were blue plastic-handled Marples) that were conveniently/routinely sharpened with a grinding wheel, and a set of prize Sheffield chisels that were solely hand sharpened and honed. The good ones of course were never lent out nor used for 'common' work and the expendable chisels had to be replaced every couple of years when the blades became overly short. The good chisels on the other hand are still in service 40 years later and there's lots of life left in them.
You can be very sure that the lifespan of most axes is shortened considerably when they're sharpened by amateurs with power tools.
It's funny, because any good axe or tool doesn't need to be maintained by power tools. It just has to set once properly either by the maker or user. Then used without mistakes and used expertly.

But things happen.

Also time is money if it's a profession.
No time to smell the rose, just get it done.
Takes more skill to use power equipment too.

If it's just a hobby like for everyone here. Then take all the time in the world to reprofile and repair. Just a hobby. Can be quite relaxing.

Well there aren't any professional axe swinging jobs any more. It's all hobby now.

But people who make new axes will use equipment.
Yet they have to battle people who don't understand how to use power equipment about loss in temper.
Like anything there is a skill or training involved in using the power equipment properly.

Its not for the average Joe

Any arguments I've seen about loss in temper are from people that don't use 2x72 grinders on a regular basis to have the competency.
 
Lol whut? What are you even saying here? All I said was that using a jig like that will put a hollow grind on your bit, and that I was curious if the intended wheel diameter had been given for the jig since all the dimensions shown on it were kind of meaningless without knowing the right wheel diameter.

Anyhow, here's some info from the 1960 textbook "The Farm Shop" detailing good technique for a dry motorized grinding wheel.

16999151_10212017477220690_1011758067526437816_n.jpg


16996518_10212017478260716_4088389811803097796_n.jpg
That high speed bench grinder with the carborundum wheel right out of the fifty's is exactly why power tools for sharpening get a bad rap. It ruined more axes than any other cause.
 
That high speed bench grinder with the carborundum wheel right out of the fifty's is exactly why power tools for sharpening get a bad rap. It ruined more axes than any other cause.

If memory serves correctly all of the grinders shown in this particular book are belt-driven and so probably don't have the same RPMs as an electric bench grinder, but it's a combination of inexperience, high speed, and cheap wheels that cause issues. Only one of the three potential problems may be permitted to be present at a time. An experienced man can use cheap wheels effectively at low speed. An experienced man may use good wheels at high speed. An inexperienced man can use good wheels at low speed. Rock, paper, scissors. :D
 
If memory serves correctly all of the grinders shown in this particular book are belt-driven and so probably don't have the same RPMs as an electric bench grinder, but it's a combination of inexperience, high speed, and cheap wheels that cause issues. Only one of the three potential problems may be permitted to be present at a time. An experienced man can use cheap wheels effectively at low speed. An experienced man may use good wheels at high speed. An inexperienced man can use good wheels at low speed. Rock, paper, scissors. :D
Hummm???
I am going to assume there is an adult on the other end.

I am not going to get into a debate with you on the merit of using equipment like that. Its just not worth my time. If you want to advocate their use for sharpening axes go right ahead...
 
Hummm???
I am going to assume there is an adult on the other end.

I am not going to get into a debate with you on the merit of using equipment like that. Its just not worth my time. If you want to advocate their use for sharpening axes go right ahead...

Well that's unnecessarily rude...

But to address your statement, I'm not advocating the use of dry high-speed grinding wheels. Just the technique used when grinding on a wheel-shaped abrasive regardless of speed.

But my rock-paper-scissors statement stands. Properly formulated quality wheels with more abrasive content and less binder will shed grit rapidly to expose fresh cutting surface, which minimizes heat buildup. Cheap wheels are made very hard and mostly of binder, and so they tend to rub and generate friction instead of cutting the material efficiently. The belt-driven grinders shown in the manual pages I posted was almost certainly not as high speed as a modern electric bench grinder, and so would also be less prone to overheat the bit. An experienced person may use a cheap wheel at low speed and still get work done without damaging the bit even though it'll take them a while. An experienced person may also use a quality wheel made for cool cutting properties at high speed without damaging the bit. An inexperienced person would only reasonably be able to use a cool cutting wheel at low speeds without causing damage.

Using a high speed anything to grind a heat treated steel tool is not recommended for the novice. If it must be a mechanical sharpening device, it should be slow speed and preferably liquid cooled. But novices would do well to stick to manual methods until they have a really solid feel for the geometry they're trying to create and how to produce it.
 
My 2 old fashioned belt drive grinders both came set up to run at 1725 rpm. Those old electric motors were typically either 3450 rpm or 1725 rpm. You have to look at the size of sheaves on the motor and grinder drive. Motor speed alone alone is only half the story.

Wheels designed to shed abrasive do cut much cooler. It's my preference for bulk material removal. All wheels require great care to avoid damaging the temper. Live and learn.
 
My 2 old fashioned belt drive grinders both came set up to run at 1725 rpm. Those old electric motors were typically either 3450 rpm or 1725 rpm. You have to look at the size of sheaves on the motor and grinder drive. Motor speed alone alone is only half the story.

Wheels designed to shed abrasive do cut much cooler. It's my preference for bulk material removal. All wheels require great care to avoid damaging the temper. Live and learn.
Not all.
P1010014_zpsupmjnodj.jpg

I actually have a motor driven sandstone grinder that I have never plugged in. It a home made job with an aluminum reservoir. I just picked it up for the wheel but it might actually be nice.
 
That high speed bench grinder with the carborundum wheel right out of the fifty's is exactly why power tools for sharpening get a bad rap. It ruined more axes than any other cause.

I guess no one told them to dip it in water when it got warm.

Just because some people lack experience and understanding about how to use power equipment doesn't mean we have to blanket all power tools as "bad"

No need to punish the competent for the incompetent.
 
I guess no one told them to dip it in water when it got warm.

Just because some people lack experience and understanding about how to use power equipment doesn't mean we have to blanket all power tools as "bad"

No need to punish the competent for the incompetent.
The high speed bench grinders are bad and the wrong tool for the job. But you can certainly use what ever you like.
 
Cheap hard wheels will burn steel fast and shouldn't be used on anything but mild or annealed steel. Good for grinding the mushrooming off an old cold chisel or splitting wedge or shaping metal hardware etc. but not anything you'd want to touch heat treated steel to because it'll heat so fast it'll be burnt in a literal half second, and the wheel can end up hiding the burn discoloration because it's still spinning and abrading it off. But hey--those crap wheels will last a long time at least. :rolleyes: But a good quality white aluminum oxide wheel in a medium hardness or softer will work fine for dry grinding as long as you know good methods of heat mitigation.

Slow speed wet grinders are great and I have both an electric one and a manual one. But they mostly get used for doing minor periodic regrinds on scythe blades that haven't been badly abused or for minor touchups on chisels and hand plane irons. They're too slow for doing any serious stock removal and so I use the belt grinder with good quality fresh belts and a light touch for any of my heavy grinding. I can grind scythe blades with edge angles of only about 7° per side with a web 1.5mm thick or less without getting even a hint of discoloration despite the edge and the region immediately preceding it being so very thin.
 
I have a cast iron one very similar to that one spotted. I have had my eye on it for a couple years now. Hasn't had a for sale sign on it yet but I suspect its coming.
Not unnecessarily bulky and hand powered. I imagine they are not light. Would be a nice get. I had a chance to pick up a large stone attached to a trailer a while back. It was pretty beat up. In hindsight......
 
Not unnecessarily bulky and hand powered. I imagine they are not light. Would be a nice get. I had a chance to pick up a large stone attached to a trailer a while back. It was pretty beat up. In hindsight......
They are problematic if the stones are not good. And replacing the bearings is something I have yet to really solve also. They are just a mess all the way around to repair. They come up fairly regular if a guy keeps his eyes open. Just get a good one right from the start.
 
Back
Top