KMG rotary platen attchment

Gossman Knives

Gossman Knives

Edged Toolmaker
Knifemaker / Craftsman / Service Provider
Joined
Apr 9, 2004
Messages
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I've been eyeballing this attachment for awhile. Trying not to sound to dumb but what exactly can be done with this attachment that can't be done with the existing attachment? What are the advantages of having it? Anyone have one? Thanks
Scott
 
Scott...I may be wrong here but I think I might be the greatest proponet for Rob's rotary platen. I had an idea that it would enhance the way I wanted a knife to be....and when I put it to use...it was like a godsend.

I see that you are a convex grind man....me too....however, I found that sometimes a convex can be just a bit too thick above the edge and though while sharp, just doesnt make the cuts I want.

I got to looking at the Bagwell knives I own.....at first glace they look flat ground....but start to convex then to a zero edge. That is what I wanted....alot of mass in the spine to cleave....but a fine edge.

So what I do is start all my blades on the flat platen.....once I have the grinds almost all the way to the spine....then I switch to the rotary platen....on its stiffest surface (you can rotate it). With an 80 grit belt you can now work on the edge geometry to get it finer and convexed and everything just blends together nicely and you'd be amazed to see how consistent the grind is all the way. You can rock the blade to get exactly the geometry you want.

Since I start as a flat grind...it is a bit tricky to clean up your shoulder area with the rotary platen....but it is easy to figure out with a little practice.

You would also be amazed at how fast the rotary can fix dips and other errors. I demonstrated this once by gouging a blade and fixing it in a couple passes.

Another added plus is because the surface is flexible you can get away with using a cheaper belt because there is no bump or slap at all while running....it is very smooth.

Slow the grinder down and use the platen to do final grinding and geometry adjustment after heat treat and you wont know what u did without it.

I have seen people assume that it is merely a sharpening attachment....it is not....and really to darned aggressive to use it as such.

:thumbup: :thumbup: :thumbup: to the rotary platen:D
 
Thanks for the detailed info Greg. Sounds like a good Christmas present to myself.:D :D
Scott
 
Greg hit it on the head. Also, by adjusting the tension of the rotary belt and thus the deflection (radius), one can also adjust the convex grind for different size knives.

Rotate to a larger distance between the wheels, and it works well for handles.

It's just a really nice fit between a platen and a slack belt.... I wouldn't hesitate to buy one again.
 
fitzo said:
Greg hit it on the head. Also, by adjusting the tension of the rotary belt and thus the deflection (radius), one can also adjust the convex grind for different size knives.

Rotate to a larger distance between the wheels, and it works well for handles.

It's just a really nice fit between a platen and a slack belt.... I wouldn't hesitate to buy one again.
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Yep!!! Me Too:thumbup: :D
 
Blade Show; nice guy. He had two or three of these with him so I pounced on one for cash and saved shipping. I did'nt have a clue what I was going to use it for. Now it sat around the shop for a while and then I gradually started useing it for various things. I'm not a convex sort of guy but I now use the heck out'a it for handles of various sorts; not the roughing out of them but the 80 grit on down. A VERY cool attachment. I made two quick change additions for it and I'll post pix of them if you like but here's the sort of handles it comes in handy for...

magumba15.jpg


magumba18.jpg
 
That's a good looking knife Anvilring. I will definately be getting one now.:D Thanks for all the replies.
Scott
 
Blade Show; nice guy.
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who, me? :D

The blade show is so frickin' hecktic...starting Thursday at noon untill Sunday when I can finally drive away from the loading dock. By the opening of the show on Friday, my back is broken and I've run out of adrenalin....and I still have 3-12hr days of non-stop action and 12 tons of machinery to move!!!

Me? nice guy at the Bladeshow....you are too kind!:D :D (hee hee)
 
Rob,
Don't lead em on. You're a nice guy, even at the Blade show.

Scott,
Let me catch a couple of questions in this thread. S7 make a decent chopper and is great for wood turning tools. Here are a couple of big blade from it, done on the rotary platen.
 

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rfrink said:
who, me? :D

The blade show is so frickin' hecktic...starting Thursday at noon untill Sunday when I can finally drive away from the loading dock. By the opening of the show on Friday, my back is broken and I've run out of adrenalin....and I still have 3-12hr days of non-stop action and 12 tons of machinery to move!!!

Me? nice guy at the Bladeshow....you are too kind!:D :D (hee hee)
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Naw, I can attest to that! Rob's a great guy regardless how tired he is. :D

As to the rotary platen I don't have much to add except that I also use the "point" wheel as a 2" contact wheel. Works great. The rotary platen has to be right up there for the best money I've ever spent (on tools I mean ;)).

Go for it Scott, you'll be very happy.
 
Thanks again.;) I will have one before the year is out.:D
Scott
 
Yes, Rob is a great guy, even at the blade show. Just a little stressed, thats all. Besides doing everything Greg talked about, the platen is great for handle work. No more raised pins!!
 
I forgot to mention, Kit, I just finished profiling and grinding a blade from S7. I going to HT it in a day or so. I'll post some tests after I get it together. BTW, love that big knife your posted here.:thumbup:
Scott
 
My name is Robert. I'm a convexaholic. That attachment is more than worth the money. I made the cost back very quickly, and have since continued to make it back. I find myself cycling through the different "lengths" the system offers. I don't recall what mine cost a couple of years ago, but if it were stolen, I wouldn't hesitate to call Rob and get another on the way to Texas.
 
I watched Greg intentionally put a mark in a bowie he was working on. The mark wasn't a standard grinder mark; it was a nasty gouge. He was able to get the gouge worked out in a few passes with (if I remember correctly) an 80 grit belt.

Greg's demonstration pretty much sold me, even though I still haven't bought one. I'll be picking one up in the next month or two though.
 
Burchtree said:
ahhh crap. Now I want one. :( :D
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He he he! There're just some things life requires. I've said it before, the rotary platen has to be one of the greatest innovations for knifemaking ever.

It took me a while to learn how to convex grind on it the way I wanted to though. The secret for me is to use fresh belts and light pressure. The thing is amazingly aggressive and makes a beautiful almost flat grind with the right pressure. I've been pretty conservative in how tight I make the belt, I suppose I could crank it up a little. But I also like to use it for handle work, where the stiffer surface isn't as handy.
 
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