Fixed Disc Sander From Angle Grinder




I always found myself needing a bench mounted disc of belt sander for rounding edges of wood mainly when building wooden toys for my son. Being a tight ass meant that shelling out NZ$180 for a unit like the one in the photo was not an option especially since i could get a bottom end angle grinder for only NZ$15 + a snading disc attachment for $NZ8

Mount it to a box, add a solid work surface and TADA a 10000rpm wood destroyer..!!

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Step 1: Find a Suitable Box

First find or make a wooden box - at least one side and the top must be pretty square to each other. I used an old nail box.

Step 2: Procure Cheap Angle Grinder

Buy the cheapest angle grinder you can find, this one cost me $NZ15 for 10,000rpm and a 12 month warranty. 100mm is the smallest available but you could get bigger.

Also get a disc sanding attachment, either the sticky back type or the velcro type will work.

Discard the angle grinder handle and safety guard, then attach the sanding disc to the spindle.

Step 3: Mount the Grinder to the Box - Cut Slot

Mounting the angle grinder and cutting the top slot was actually a series of steps but they all happened at once to get the arrangement right so i will document them all here.

I first positioned the grinder with the centreline of the spindle about 30mm from the top of the box. This meant having it on an angle.

Next i screwed the 2 square pieces of timber as shown to the side of the box to locate the grinder.

Then i drilled a series of holes on each side of the grinder body and used 6mm cable ties to secure it down. Cable tie ends are inside the box.

I didnt really trust the cable ties at first so i decided to make a steel bracket to fix the existing handle mount hole to the wooden block - as shown in the second photo. This may actually be overkill but hey it is going at 10,000rpm.

Cutting the slot in the top of the box was actually done before the sanding disc was attached - just make sure it is big enough to allow at least 10mm clearance around the disc - you dont want it touching anything.

Step 4: Attach a Solid Work Surface

You need a solid piece of wood for the work surface, make sure one edge is straight and square (not chamfered at the top)

Position the square edge about 1mm away from the angle grinder disc face.

I could have just nailed it down but that would make changing the grinder discs impossible without removing the grinder.

My solution to this was to hinge the work surface and hold it down with a sliding bolt latch - the photos show the installation pretty well. Main thing to note is that the wood doesnt touch the sanding disc but is as close as practical to the disc.

Step 5: Add a Base and Fire It Up!

If you box doesnt have a base like mine didnt, add one since it will help keep all the sanding dust inside.

Also add another cable tie to hold the power cord if required, it will depend on your grinder orientation.

Now plug it it and sand some wood....

I dont know how powerful proper disc sanders are but this one howls..!

Ii is best to use the side of the disc that is travelling downwards to sand with as the dust goes into the box, if you use the other side it goes up into the air....

A safety guard could be added if required also.



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    13 Discussions


    5 years ago on Introduction

    Build wooden toys for your son? Very loving father, must support. In addition, the use of angle grinders this idea is very good.


    9 years ago on Introduction

    Going to do this with a old grinder wire a dimmer switch inline a foot pedal and drill some small holes in the box where the dust will fall through and be sucked in by a vacuum


    11 years ago on Introduction

    Attach an inline RPM controller and wire tie the control knob to the base, then you can easily attach a 7 1/2" disc and boom! you have full size sander. It cut down on the torque 'cause it' not geared down, but still very effective.

    Mr. Rig It

    11 years ago on Introduction

    Great Idea! Now I can use my angle grinder for yet another purpose. I currently have it set up as a cut off saw. It works great, come to think of it I may have only used my grinder twice as an actual grinder.
    Good Job.
    post comment


    12 years ago

    What if you attach a vacuumcleaner to the box? Then you have less dust in the working area. And saves time cleaning it. To reduce the noice it's also possible to mount a beam slantingly to the sides of the box. So that the sides of the box won't function as a soundboard and won't resonate. Note that the beams are off centre and are unequal placed. That will prevent resonation.


    12 years ago

    Cable-ties, fantastic. Surely cable-ties are one of the better inventions of the 20th century?


    12 years ago

    This thing must rip stock down! I have seen discs you can put on a tablesaw, or radial arm saw to attach discs to. RPM and noise might be a bit saner with those. Maybe one could use a beat old sawblade to the same effect? Grind the teeth off it or something. Me, I actually have a stationary disc sander. Don't use it very much but I got one. My belt sander is a rig I should post that someday. The belt sander I use a lot. One of the angle grinders I have I have dedicated to belt sanding too, and I made a fixture to clamp that down. A piece of wood that bolts to the handle thread. Throw that in a vise and you're good to go!


    12 years ago

    Could you maybe fill the box with something to help cut down on the noise? Maybe some foam panels along the inner walls. That hollow box must make a great resonating chamber!

    1 reply

    Reply 12 years ago

    Good idea... it surely howls... I just did a decibel test and it make 98dB at about where your head is when using it - definitely earmuff material...


    12 years ago

    Thanks trebuchet03 ... its my first instructable...


    12 years ago

    I vote this... at the very least, honorable mention worthy for the project of the month contest.