Surface Grinder attachment

Chris Railey

KNIFE MAKER
Does anyone have a suggestion for a surface grinder attachment that would fit my pheer 454? I know I could build one but I just dont want to get $500 into building one, ruin it, and still have to buy one.
 

KenH

Well-Known Member
I looked up the Pheer 454 grinder - looks like it's a standard 1.5" tooling arm with dual slots. If so most any of the commercial SGA should fit just fine. My STRONG recommendation would be the Reeder SGA
Stacy on another forum has one and is impressed with it. While I don't own one, I've looked at it pretty good and am also impressed. "IF" I were purchasing a commercial SGA it would be my choice hands down. The OBG https://www.ebay.com/itm/263146335672? is less expensive and should work ok. BUT - the Reeder is a step above.
 

Chris Railey

KNIFE MAKER
I looked up the Pheer 454 grinder - looks like it's a standard 1.5" tooling arm with dual slots. If so most any of the commercial SGA should fit just fine. My STRONG recommendation would be the Reeder SGA
Stacy on another forum has one and is impressed with it. While I don't own one, I've looked at it pretty good and am also impressed. "IF" I were purchasing a commercial SGA it would be my choice hands down. The OBG https://www.ebay.com/itm/263146335672? is less expensive and should work ok. BUT - the Reeder is a step above.
Thanks very much
 

EdCaffreyMS

"The Montana Bladesmith"
I don't have a lot of personal experience with any of the "attachment" type surface grinders.... I've only used a couple.....those being the one for the TW90, and then another "custom" made one.
Having an actual surface grinder in my shop, did give me something to compare them to though..... what I saw/found, in my limited experience, is that the attachment versions are not even close to the precision that an actual surface grinder offers. Now, that being said, I look at surface grinders as to how precise they flatten materials/parts for folders, where I demand no more than about two thousandths variance, and prefer less than one thousandth. My little elcheapo harbor freight, 6x12" surface grinder will hold to 1/2 thousandth or less over a 6" span, and under two thousandths over it's 12" capacity.....and it took a lot of work to get it there.

The BIGGEST issue with any surface grinder attachment used on a 2x72 grinders is.....unless you have a dedicated, super hard contact wheel, that is used exclusively for the surface grinder attachment, then you run into the issue of the contact wheel(s) being too soft for the application, and the work piece/steel you're grinder comes out with a convex face, and destroys the entire reason behind using the surface grinder attachment. (that's something that most who offer the surface grinder attachments for sale....conveniently leave out of their sales pitches)

What I saw with the surface grinder attachments I mentioned above were 2-3 thousandths over a 5" span/piece, and 3-5 thousandths over their 10" capacity. Take that for what it's worth to you, and I would expect the variance to differ based on many possible factors, but my opinion is that IF the reason you want a surface grinder is for building folders, I'd bypass the attachments, and get a stand alone surface grinder. While I'm sure there are folks out there making folders with only a surface grinder attachment, I can't image the finished folders being very good/smooth IF the tolerances are the same as what I was able to achieve with the attachments. However, if the intent of a surface grinding attachment for a grinders is spawned through some other need, where very high precision isn't required, then I'd say it would be a no brainer compared to the cost of a stand alone surface grinder. It all depends on the individual requirement(s).
 
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Gliden07

Well-Known Member
For the money that makers are getting for the add on Surface Grinders you could go and buy a used real surface grinder an probably have a couple of bucks left over! I have a Reeder grinder and love it! I'm sure the Surface Grinder attachment is a quality piece but its expensive!
 

bladegrinder

Well-Known Member
I'm guessing the big selling point in the attachment units is a matter of saving space over the foot print of a full size surface grinder.
But like Ed say's....and I don't care what I've read elsewhere, the absolute precision isn't there with attachment units when you figure in the rubber contact wheel and abrasive belts.
I have a small Sanford surface grinder made in the 50s that only takes 1/4" wide wheels that I think was made more for some kind of jewelry work or something along those lines. it takes forever to do a folder blade, but when it's done it's absolutely dead on.

Now that I have a new bigger shop I'm looking for a full size surface grinder.:D
 

KenH

Well-Known Member
I mentioned above were 2-3 thousandths over a 5" span/piece, and 3-5 thousandths over their 10" capacity.
Something is wrong if that's the best you're getting out a SGA. Here's what I've got in past, I think that's a petty chef with blade around 5" to 6", then with a 4 to 5" tang giving around 10" overall length:
Tip.jpg

Middle.jpg

Tang.jpg

I'll admit that's perhaps the best I've got. The normal is more about .001" to .002" over a 10" to 12" span. Many years ago I worked with surface grinders where we had to keep things within 1/10 thou, and they'll do it, "IF" wheels are balanced, bearings are right, and the wheel is dressed correctly. I don't think 1/10 thou is really needed for much of knifemaking. Not in my world, perhaps in some of the $3,000 folders I've handled that were more like jewelry than a knife.

the issue of the contact wheel(s) being too soft for the application, and the work piece/steel you're grinder comes out with a convex face,
If you are taking a really heavy cut of .005" or so then you will have that problem with a soft wheel. The trick is to make the last couple of passes down around the 1/2 thou to 1 thou and the softer wheel isn't so much of an issue. Some folks who don't wish to take shallow cuts at last will use a 90+ duro wheel and that works pretty good.
 

EdCaffreyMS

"The Montana Bladesmith"
Thats super for a SG attachement! (I assume that's what you're talking about?) That shows that it is a viable option.

On the wheel hardness issue, I mentioned that simply because most people have not idea that the convex face thing can happen. I've fielded many, many phone calls and emails about the convex face, and for most, who were using softer wheels, I gave them pretty much the same advice as what you mentioned on the last few passes.....I think the problem is that many just got at it as hard and fast as they can....then have not idea why, when things go south. :) Just like any piece of machinery.....gotta learn how to use it properly.
 

KenH

Well-Known Member
Thats super for a SG attachement! (I assume that's what you're talking about?) That shows that it is a viable option
Yes, it's one of the very early homemade SGA (Surface Grinder Attachments). I built it a yr or so ago when we were first learning about building them.
One-Armed built the first one homemade SGA using Travis's commercial SGA as a pattern. I think perhaps I "might" have been second.

Please do understand those numbers in the photos are my very best. As I said my normal measurements are in the .001" to <.002" range depending on grit of belt and depth of cut. I understand .001" to <.002" is fairly standard, even with a "real" surface grinder that's been changed over to 2"X72" belts as many have done. As you know the cost of good grinding wheels for a "real" surface grinder isn't a "no cost" thing.
 
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