Easy grinding jig using pin from RxR

Fred.Rowe

Fred.Rowe

Knifemaker / Craftsman / Service Provider
Joined
May 2, 2004
Messages
6,848
This jig takes a little time to match to your grinder. But makes for some really nice flat grinds. The bubble sets your grinding angle from 11 to 8 degrees elevated from the platen. These angles will cover everthing from big bowies to small fillets. Measure the angle from level to the platen face using a 2 or 3 foot level. Subtract 11 degrees from that angle and cut the mounting block top for bubble. The bottom is square with the sides [90degrees] and maget assembly. I use a miter box so I can set the correct angle. Do the same with 10, 9 and 8.degrees. Epoxy each bubble to top of block,epoxy the magnet and you are ready. I use the bubbles by themselves, sometimes, using double sided tape attached to the riccaso. Stick the magnet to the tape and grind away. It alows you to reproduce the same angle of pitch every time by watcing the bubble.
The bobby pin looking piece is from CSX RxR. The handle that holds the tang is a file holder from Sears. I run this jig on my KMG with great results. It would not work well with a vertical platen. This is just one of many ways to approach the subject. Fred

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Will be happy to answer any questions if I can. :thumbup:
 
rocketmann said:
:confused: I don't get it:confused: :confused: Could you show it in action?? I'm pretty thick sometimes..
Click to expand...

The last picture shows the jig with the bubble floating. This would put the blade bevel you are grinding, at an 11 degree pitch from the planten. By establishing the pitch of the platen relative to level you can control the pitch at which you grind. You move the bubble from one side of the grinding jig to the other side; whicever side you are working on. this makes both sides of the blade exactly the same. The bubbles don't lie.
If you read thru the original post and make a sketch it will become clear. If you are still having trouble give me a call on my 800 number. You can find it on my website. I have ground upwards of 350 knives with this jig and would not want to do without it. It is wonderful for the big knives. It makes for a beautiful flat finish. Fred
 
I still don't understand, So you don't try to keep the bubble between the lines? Your last pic shows the bubble b/w the lines but the blade angle would not make much of a grind. I also have a KMG but the platen is vertical from the factory? how is yours set up??:confused: :confused: :confused: :confused:
 
Let me make up a drawing that shows this a little better. I will post it tomarrow. Fred
 
rocketmann said:
I still don't understand, So you don't try to keep the bubble between the lines? Your last pic shows the bubble b/w the lines but the blade angle would not make much of a grind. I also have a KMG but the platen is vertical from the factory? how is yours set up??:confused: :confused: :confused: :confused:
Click to expand...
I have my platen set at around 45 degrees from horizontal. If I subtract one of my four angles,[11degrees] from that 45 degrees that gives me the angle at which to cut the top of the block where the bubble sits. If I want the blade to grind at a pitch of 11 degrees from the platen surface, I cut the top angle of my wooden block at 34 degrees on the miter box. That is the 45 degrees[planten surface] minus 11 degrees = 34degrees. When I sit that bubble thingy on the riccaso or on the jig and make the bubble float between the lines I get a grinding angle of 11 degrees above the platen, 10 degrees above the planten and so forth. You can set up for as many angles as you feel you need. They are all relative to horizontal because all of your measurements are taken from horizontal.
When I designed this jig the only way I could make it clear to myself was to make a drawing showing a profile of my grinder with a level sitting on top of it with the bubble between the lines. Measure the angle down to the planten surface and go from there.
I have found that these four angles 8,9,10 and 11 degrees above the platen surface will flat grind any blade from 2" wide to 1/2" wide.
No one here is dense, we just learn differently.
As I mentioned earlier, I don't think this setup would work on a vertical platen. Fred
 
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