Sharpening jig for a belt grinder- Tormek style

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bjansen

Joined
Feb 4, 2013
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229
I have been thinking a while about a simple way to clamp a blade and hold it at stable agle on my belt grinder for reverse, slow speed final sharpening. I was thinking about a bar and a tierod style joint to which it would slide on, and a clamping mechanism to hold the blade. Just recently someone asked about a Tormek grinder and it dawned on me that a simple way to do this would be to incorporate a tormek style guide bar into a jig to mount directly to the tool arm.

Attached are some pics of what I made. Not the nicest jig, or the most precisely made one....but it is square to the platten and works like a charm.

I essentially purchased a $30 Jet arm from Amazon along with the tormek knife jig. All in under $90 for the build.









 
I built a similar jig that used a Tormek clamp about ten years back. I replaced it with an auto-adjusting fixture with ten articulated clamping points. It has continuous feedback, updated every few microseconds, to self adjust for changes in blade curvature. I would take a photo of it, but one half of the device would be needed to hold the camera :)
 
I historically used an auto adjusting clamp as you described, however I don't think mine adjusted as fast or consistent as yours.
 
It almost looks like it would work better if your horizontal bar was pulled out further and the black cup on the holder was reversed. This way the weight would keep the cup against the rod. The way it's setup know you have to have upward tension of the cup on the horizontal rod. Just a thought.
 
That is a good point, I think it would also help with the grind angle that the tip experiences when the jig is turned. I will try that on the next one
 
bjansen said:
That is a good point, I think it would also help with the grind angle that the tip experiences when the jig is turned. I will try that on the next one
Click to expand...

Let us know how it works. Should work out great with the right angle on the belt. Will you sharpen on a slack belt or the platen?
 
I used a platen on the knife I did this weekend. Used a 220 belt, then a 400ish, then went to the steamboat sharpener, then strop and it worked very well.
 
Bjansen: Sorry to go off-topic, but what are those red hoses that appear to be coming out of your platen? They have me very curious!
 
I have a chilled platen from Nathan the Machinist. That is a $5 Harbor feight air hose, cut in two to supply and return water to the platen. I used an HF, $10 aquarium pump and have an old coffee tub (which you can see in the pic) full of water under the bench for the supply/return. .
 
bjansen said:
I have a chilled platen from Nathan the Machinist. That is a $5 Harbor feight air hose, cut in two to supply and return water to the platen. I used an HF, $10 aquarium pump and have an old coffee tub (which you can see in the pic) full of water under the bench for the supply/return. .
Click to expand...

Aha! I thought that might be the case! I had a similar idea to try to stop a tool-steel platen from wearing, but hadn't seen anyone else doing it! Nice to know it's not a crazy idea!

Thanks, sorry to go off topic.
 
I tried to reverse the plastic cup on the Tormek last night..and it is possible, but without alteration you do not get the tension/friction that an integral o-ring provides inside the cup (which essentially keeps the adjustable plastic piece in place).

I do agree that having the weight sit on the bar, rather than having to push up on the bar is ideal. Having said that, I would recommend anyone else that tries this to first determine which way you want to go.....do a mock up of how you want toe Tormek knife jig to interact with the guide bar as this will provide you a good idea of the mounting location of said bar.

I am probably either going to stick to what I have, or I may even make a new plastic cup for the Tormek jig.
 
That's some beautiful machine work. We made a similar rig to adapt the Tormek jigs to our Bader belt grinder, but much simpler, just a length of 12mm rod welded to a bit of bar stock that was slotted for the work rest bolts. We learned that the most useful location for the guide rod (for the jigs we use anyway) was near the bottom of the platen, some tools would have to be sharpened in the area between the contact wheel and the platen... so we cut and re-weld the bar stock into an "L" shape to lower the rod. It sees a fair amount of use when turning tools or chisels need re-profiling.
 
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