The Mother Of All Belt Grinders

It seems like everyone is building belt grinders these days. You might think [Jeremy Schmidt] is just hoping on the bandwagon, but you’d be wrong. He took a full two years to design the perfect belt grinder for his needs. Now he’s built his perfect beast, and we must say, it’s quite impressive!

[Jeremy] had seen grinders which can tilt, but most of them tilt the entire machine, including the table. He designed his machine with an independent table. This means the belt can be placed at any angle, while the table remains flat. He’s achieved some really interesting finishes with a course grind on a 45-degree angle to the workpiece.

No build is without its problems. In [Jeremy’s] case it was building the box which acts as a receiver for the machine and the tables. Regular square tube stock wasn’t quite rigid enough, so bar stock was the way to go. The first attempt at building the box resulted in a warped tube, due to the stresses of welding. [Jeremy] was more careful the second time, moving from section to section of the four welds. This kept the heat from building up, and the box stayed straight.

The final result is an incredibly rigid machine which definitely will withstand anything that [Jeremy] can throw at it.

If you want to see more belt grinders at work, check out [Bob]’s treadmill belt grinder, or [Mike’s] conversion.

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Turn Your New Years Resolution Into A Belt Grinder

We’re just over a month into the new year, and some people’s resolve on those exercise plans are already dwindling. There’s some good news though. That treadmill can be hacked into a nice belt grinder for your shop.

[Bob]’s treadmill belt grinder is based on a 2.5 horsepower motor he salvaged from a broken, donated treadmill. This motor needs 130 VDC to run, which is a bit of a challenge to generate. Fortunately, lots of treadmills seem to use the same MC-60 motor controller, which is compatible with this motor. Due to the widespread use of this controller, they can be found on eBay for about $30.

With the motor spinning, [Bob] built up a frame for the grinder, added rollers to hold the belt, and a spring based belt tensioner. The motor’s speed set point is controlled by a potentiometer, and the controller varies the power to keep a constant speed. Since the motor is capable of some serious RPM, a tachometer was added for feedback to prevent high-speed belt shredding.

The final result is a very professional looking tool for under $200. What would a grinder like this be used for? Knives of course! 2″ belt grinders are perfect for shaping and grinding knives and swords. In fact, you can see one in use in this sword hack.

Check out a video of the build after the break.

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Treadmill To Belt Grinder Conversion Worked Out

[Mike] had a bunch of disused fitness machines lying around. Being a skilled welder, he decided to take them apart and put them back together in the shape of a belt grinder.

In particular, [Mike] is reusing the height-adjustment guide rail of an old workout bench to build the adjustable frame that holds the sanding belt. A powerful DC motor including a flywheel was scavenged from one treadmill, the speed controller came from another. [Mike] won’t miss the workout bench: Once you’re welding a piece of steel tube dead-center on a flywheel, as happened for the grinder’s drive wheel, you may call yourself a man (or woman) of steel.

The finished frame received a nice paint job, a little switching cabinet, proper running wheels and, of course, a sanding belt. Despite all recycling efforts, about 80 bucks went into the project, which is still a good deal for a rock-solid, variable-speed belt grinder.

Apparently, disused fitness devices make an ideal framework to build your own tools: Strong metal frames, plentiful adjustment guides, and strong treadmill motors. Let us know how you put old steel to good use in the comments and enjoy [Mike’s] build documentation video below!

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An Extremely Useful Shop-Built Belt Grinder

What’s green and black and used all over the shop? It’s [Make It Extreme]’s newest build, a scratch-built belt grinder. And as usual, the build video gets us in the mood to cut metal.

We’ll go out on a limb here and state that the lathe, and not the belt grinder, is the essential metalworking tool. That’s pretty clear from this build – the running gear is machined entirely on a lathe. But as central as the lathe is to machinery making, belt grinders like this one have to rate right up there in terms of shop utility.

You can sharpen with them, quickly remove stock, clean up welds, form chamfers, and remove rust and corrosion. They’re great all-around tools, and with the quick-release idler feature that this one has, fast belt changes for different jobs make it even more flexible. We’d like to see more adjustability in the work table – the ability to angle the table relative to the belt is very handy – but in all this is a great build and a nice tool to have.

On top of it all, watching the [Make It Extreme] builds – like this sandblaster, spot welder, or belt sander – is like high-speed shop class. There’s a lot to learn, although we have to admit that welding in shorts and a T-shirt gives us the willies.

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