Making A grinder VS?

[MikefrMd]

Hi Everyone,

I was given a Ryobi grinder by a friend and was gonna use it in my shop to sharpen chisels.

The problem is its a fixed speed of 3600 rpms is that too fast too sharpen chisels and if so is it possible to make it variable speed to slow it down for sharpening? I was planning on getting a wolverine to use with it.

Thanks,

Mike

 

[Firefyter-emt]

NO... Not unless it is a three phaze motor (330v) and I kinda dobut it! In my opinion, keep that one with a rough wheel and slap a wire wheel on the other side for stuff around the shop and buy the low speed one from Woodcraft that comes with 2 proper stones on it. This will keep you from wanting to grind something down on the good stones. Idealy, build your self one of those flip top stands to put it on so you can flip over the top and switch which one you want to use. []

 

[VisExp]

The other problem is the Ryobi probably has 6" wheels. Ideally for sharpening you want at least 8" wheels so they put less of a curve on the surface you are grinding.

 

[MikefrMd]

The Ryobi does have 8" wheels....I thought maybe there might be a mod or another device to control the speed. Something that you would plug the grinder into to control voltage.

Would it make a good buffer?

Mike

 

[THarvey]

What about one of the variable speed controllers, like you use with a router. It plugs inline with the AC.

Don't know if that would cause other problems or not. Just a thought.

 

[jhs494]

I have a delta 8" that is 110 volt single phase and it came VS.
I am not sure how it was done but I bought it that way.

 

[twoofakind]

I think the router module is just a reostat(sp?). Seems like it could work as long as the current draw isn't too much.
Andy

 

[Ron in Drums PA]

I'm not an expert in this, but a speed controller will work on some 110v motors and will ruin other 110v motors. Wish I knew the difference.

When in doubt, don't do it.

BTW, I sharpen my tools with a high speed grinder.

 

[MikefrMd]

Ron,

Do you just have to be more careful when sharpening at high speed?

 

[jhs494]

Speed equals heat, and heat ruins tools.

 

[Randy_]

The router controller "WILL NOT" work on your grinder!! They are the same voltage; but the basic design is entirely different.

You can use your HS grinder to sharpen tools. You just need a light touch and a container of water handy to cool the tool.

 

[Ron in Drums PA]

Originally posted by MikefrMd
<br />Ron,

Do you just have to be more careful when sharpening at high speed?

Basically, Yes. It just removes material faster

 

[Ron in Drums PA]

Originally posted by Randy_
<br /> a container of water handy to cool the tool.

If you are using HSS tools you will ruin then if you quench them in water. You can not get HHS hot enough from a grinder to remove the temper. Don't Worry!

Now if you are using High Carbon Steel, HCS, then yes you need to quech them in water to prevent removing the temper.

 

[Paul in OKC]

Originally posted by Ron in Drums PA
<br />

Originally posted by Randy_
<br /> a container of water handy to cool the tool.

If you are using HSS tools you will ruin then if you quench them in water. You can not get HHS hot enough from a grinder to remove the temper. Don't Worry!

Now if you are using High Carbon Steel, HCS, then yes you need to quech them in water to prevent removing the temper.

Would have to disagree here. High speed ,as you say, will not lose its temper. I have ground HSS for years for machine tools and always drop that sucker in the water when my fingers get hot! The high carbon steel and others, you do not want to get to the point where they turn blue, once there what temper they have is gone (and then you lose your temper[]) Anyway, a light touch and a dip in water after each touch will keep things cool. I sharpen my tools on an old cheapie 6" grinder. Front to clean up, and on the side of the wheel, very light touch, to 'hone', works great. (Now from all you folks who think using the side of the wheel is a no-no......)

 

[Ron in Drums PA]

Originally posted by Paul in OKC
<br />

Originally posted by Ron in Drums PA
<br />

Originally posted by Randy_
<br /> a container of water handy to cool the tool.

If you are using HSS tools you will ruin then if you quench them in water. You can not get HHS hot enough from a grinder to remove the temper. Don't Worry!

Now if you are using High Carbon Steel, HCS, then yes you need to quech them in water to prevent removing the temper.

Would have to disagree here. High speed ,as you say, will not lose its temper. I have ground HSS for years for machine tools and always drop that sucker in the water when my fingers get hot! The high carbon steel and others, you do not want to get to the point where they turn blue, once there what temper they have is gone (and then you lose your temper[]) Anyway, a light touch and a dip in water after each touch will keep things cool. I sharpen my tools on an old cheapie 6" grinder. Front to clean up, and on the side of the wheel, very light touch, to 'hone', works great. (Now from all you folks who think using the side of the wheel is a no-no......)

This topic was addressed recently on AAW
http://www.aawforum.org/vbforum/showthread.php?t=4281&page=2

 

[Firefyter-emt]

Just to say again, you CAN NOT usa a router controler on a grinder.

 

[toolcrazy]

I believe most VS motors are DC not AC. DC motors you can change the speed by varying the voltage, with AC you can not do that. It just reduces the power not speed. At least this is the way it was explained to me.

 

[Phil Joines]

Most small tool motors are "Universal". It will blow the fuse or burn out a router speed controller if you try to use it.