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J S Machine
07-29-2011, 03:42 PM
I was wondering what options there are out there for a bench mounted surface grinder. Don't really need a whole lot of Z, or X and Y for that matter. I need one for grinding knife blades.

I have all of the tools I would ever need at work for doing knives, but I'm trying to get my stuff up at home. This grinder and a mini mill are two needs at the moment.

What choices do I have and where are some good places to look?

macona
07-29-2011, 03:50 PM
There is not much out there. I have seen where people take lighter 6x12s and separate them from their base and mount them to a table.

Just make sure you dont share the same table with any precision equipment. The grit will tear things up.

Skip the mini mill and get a small knee mill. I gave my dad a bridgeport with a 30" table and it does not take up that much space. Or an old Gorton, Mill-rite, etc.

lazlo
07-29-2011, 04:24 PM
Sanford is pretty much the only benchtop surface grinder, and as you probably know, they're popular with knifemakers.

But you might consider a Harig 6x12. It's on it's own stand, but it takes up a small amount of floor space.

PeteM
07-29-2011, 04:27 PM
Just to add to Macona's point, the Delta Toolmaker grinders easily detach from their cast iron legs and would fit on a bench. However, that bench would then become a resting place for grit.

I'm not sure how well a surface grinder will work for knives since many or most have a curved edge and perhaps a tapered blade. You could create special jigs to manipulate things; but I'd guess (not being a knife maker) that abrasive belts would be more productive?? In any case, the real point is that the 6" x 12" envelope of a small surface grinder gets eaten up pretty quickly. Maybe the magnetic chuck is 5" x 10". Maybe you need to block or fixture the part with bits one and a half inches on all sides. Pretty soon you're down to 3" by 7".

lazlo
07-29-2011, 04:42 PM
I'm not sure how well a surface grinder will work for knives since many or most have a curved edge and perhaps a tapered blade.

Knifemakers use surface grinders a lot for folders, where you need to get the blade and liners uniform thickness. They don't like dressing the wheels much, so several have replaced the grinding wheel with a hard rubber contact wheel to make a belt-driven surface grinder.

Meanwhile, I've experimenting with grinding blades with a sine plate to accommodate the distal taper.

This is Gil Hibben using a surface grinder to flatten his blanks:

http://www.hibbenknives.com/knifemaking.htm

http://www.hibbenknives.com/images/Knifemaking/Suface1.jpg
http://www.hibbenknives.com/images/Knifemaking/Surface2.jpg
http://www.hibbenknives.com/images/Knifemaking/Surface%203.jpg

Bob Farr
07-29-2011, 07:47 PM
Lazlo,

Thanks for posting the Gil Hibben link. He has a very interesting site.

JS Machine,

The Sanford is the smallest bench machine which comes to my mind. It will fit inside a 2x2x2-foot cube, and the mag vise is 3x5 (vacuum tube powered!). I have one and it is useful for little stuff. I don't do blade work so I can't comment on it's suitability for that particular application. The spindle is fixed perpendicular to the x-axis, and the table does not swivel (see KO Lee, below), so this is a 'flat-n-square machine' only without fixtures. Here is a picture of a page from the brochure which shows the little machine:

http://i58.photobucket.com/albums/g272/frankenglide/SanfordGrinderFlyerp4only.jpg


The Sanfords are popular and pricy. You might consider a KO Lee tool and cutter type machine instead. The base is a sheet-steel cabinet, and the machine itself lifts right off and will fit on a bench. It will fit within a cube about 3x3x3-feet in size, with about 4.5 or 5-feet of lateral space needed for the table movement. The table swivels in the x-axis, and the spindle rotates about the z-axis, so these features may make it more suitable/versatile for blade work other than 'flat-n-square.' There are several variations of this machine configuration and most are shown in this picture:

http://i58.photobucket.com/albums/g272/frankenglide/KOLeebrochure1.jpg

Again, I do not do blade work, so the other members who do will have to comment on the KO Lee's suitaility. I do have one and I like it, though it's new to me so I don't have much time with it yet. It does have a larger work envelope than the Sanford: about 5x9 or maybe a bit more. I think they are more readily available than Sanfords and probably much cheaper. Mine was.

I hope that helps. Good luck.

Bob Farr

tdmidget
07-29-2011, 09:43 PM
The KO Lee pictured is not a surface grinder. It is a tool and cutter grinder and NOT remotely suitable for the tasks under discussion. The table does not swivel. Is this the machine you intended to post?

J S Machine
07-29-2011, 09:50 PM
I just need a surface grinder to get my stock flat. I use one pretty often at work, I just don't have one at home. I don't really need anything special, that's why I was thinking there might be a cheaper bench model. Hate to say it, but I don't have a ton of money to spend on tools. I sure wish I did, but I don't.

This is a Chevalier I have at work. I'm grinding a small folder blade.

http://i226.photobucket.com/albums/dd198/JSMachine/knives/MDA/mda55.jpg

tdmidget
07-29-2011, 09:54 PM
That won't make it flat. The magnet can pull a 1/4 ' plate down flat but when you release it it will spring right back. Put it on shims or doublesided tape to get the first side flat. The tape works best because it eliminates the magnets influence.

Bob Farr
07-29-2011, 10:54 PM
The KO Lee pictured is not a surface grinder. It is a tool and cutter grinder and NOT remotely suitable for the tasks under discussion. The table does not swivel. Is this the machine you intended to post?

Hi tdmidget,

It is the picture I intended to post. I also noted it was a t&c machine and deferred to the experts on its suitability for the OP's needs. I'm glad you posted to clarify that.

I'm probably not describing the KO Lee "swiveling" table movement properly. There are two tables, so to speak. The lower table traverses laterally. The upper table (the t-sloted work surface) has a centrally-located pin into the lower table about which the upper table can pivot several degrees either direction off of parallel/latteral with the lower traversing table. Tapers came to mind when I described that feature to the OP.

Bob

J Tiers
07-29-2011, 11:17 PM
Shere are Sanford's and there are Sanford's.

There is the small one the "SG" at 4 x 8 x 6 nominal capacity, but there is also a larger sized "small" unit, the "MG", at 8 x 12 x 12.

And you may find a Sanford "LG", 10 x 16 x 16"