Knife Grinder

I've been able to get away with simple tools for grinding my knives. But it's never been quite right. Angle grinders are inaccurate, small belt grinders are underpowerd, and over heat quickly. For a long time I've known that I need a proper belt grinder. But I've never quite had the tools to do it. 

Until now! I bought a Forney mig/stick/tig welder, and decided to tackle this project. 

I'll be honest here. My welds are terrible. I should have practiced before welding the real thing, but I was excited, and just went for it. They do hold! You'll notice in this first picture the two square tubes don't quite line up. This has caused the wheels to not be square with each other. I haven't been able to test this yet with a real belt, so I can't say for sure this will be a serious issue. But I should have paid better attention to this :(

  

 I drilled and tapped two holes for set screws. One will set the tensioner, and the other will set the tool arm. Fun fact, this was the first time I've ever tapped a hole!

 

Belt tracking is likely the most complicated part of the belt grinder. The pictures will do a better job at explaining the set up. But I'm using a bolt to adjust the angle of a hinged piece of steel. 

The whole tracking set up is also the tensioner. The tensioner tube is inserted into the larger diameter tube with a spring in the bottom of it.

  

Here it is all screwed together! 

So here is something I learned about the wheels and the bolts being used for their axles. The bolt should not tighten around the wheel! Untill I thought about it last night, I thought the bolt was supposed to death grip the wheel so it isn't loose, and holds the wheel in place while the bearing does the spinning. But in fact, you should use a second nut to secure the axle in place, and put no pressure on the wheels themselves. That way the axle is tight, and the wheel is allowed to spin freely. Plus, the wheel is plastic, and overtightening may damage them. 


My setup is rather ghetto. I'm using a bench grinder as the motor. And I have it, along with the belt grinder clamped to a bench. I finally got it to track properly, but the belt is obviously running uneven, probably due to the misaligned weld (or the misaligned bench grinder clamped to the bench.) My next step is to built a platen, and tool rest. Then fix the misalignment weld, and hopefully find a way to align the motor with the grinder better.