New tool to grind knives

I have been wanting one of these for a while so I decided to build one. My main plan is to try and make some knives but it will also be handy for sharpening and wood working. I will post some new pictures soon. I have the belt tracking but I need to do a few adjustments and then paint everything.


Nice. A grinder like this is on my wish list as well.

Thanks for sharing! I’d love to learn what sources of information you used while designing, and more details of your build, as well as likes and dislikes as you start using it.

Last week, the controller board in my old treadmill with a 3HP motor bit the dust, so there’s a perfectly good 3HP 90V DC motor sitting unloved in my shop now waiting for a new purpose in life, though I’ll need to do something to keep magnetic dust out of the insides and still cool it. Fins on the outside and a fan inside to make it be a home-made TEFC?

I’ve been thinking of taking ideas from these two sources to build a 2x72 primarily out aluminum stock, bolt-together, in order to make lathe tooling.

I expect to follow lots of advice from this truly epic thread:

That advice includes using a glass platen.

The dead treadmill also donated a pair of gas lifts, so I might use one of them for belt tension. I love reusing and recycling in the shop!

But with all the other projects I have in flight, dunno if I’ll get there this year. :frowning:


There are a couple of open source grinders out there. I think they both originate from This is the link to the one I built. Lots of great information on that site.
About the treadmill motor. I am a big fan. If you look on the shelf below my grinder in the picture, on the right is a 2.5 hp DC treadmill motor. The gear motor in the middle is also a DC motor used to change the incline. Currently I have a 2 hp DC motor on my lathe.

It is not a very good picture but you can see the control box on top. This is the one I bought I originally modified the control board from the treadmill but it burned out after a few months of use. I am not sure why. I used this Instructable to figure out how to use the existing controller board. It was fairly easy and all I had to buy was a 10k potentiometer.


Thanks! I hadn’t seen that motor supply before.

I wasn’t clear… It was the motor control board that died for me. Also it was one of the proprietary digital control boards, not the ones that you can control from a potentiometer. So the motor supply is key for me. :slight_smile:

Here are a couple more pictures of the belt grinder. I have just a few more things to add to it. I am going to put a glass platen on it and I need to make a tool rest for it.


I just finished gluing on my glass platen. I could have just bought one from usaknifemaker but I am always looking for a deal. As far as I can tell, it is just borosilicate glass. So I just ordered a glass build plate for an Ender 5 3d printer. I will be able to get 4 platens for the same price. BTW Plans for the design you show are available on this website.


I had not seen that forum, thank you!