Homemade random orbital sander attachment

[Tuomas]

Made a random orbital sander attachment with 8mm movement, to be used with drill, angle- or bench grinder.

Note, that centrifugal force that makes backing to spin, also increases its spinning speed higher than the actual speed of the used motor. This happens when its unloaded. Personally i think that using 11-13.000 rpm angle grinder is possible too much.

I used backings made to be used with 13.ooo rpm speed, and 2000 rpm with my angle grinder, ( it has a variable speed.)
My bench grinder runs 2200 rpm. I originally planned this build for to be used with bench grinder.

Works nicely, and gives smoother result than my bosch sander which has only 2.5mm movement.

When mounted to bench grinder, i can use whole area of the paper for sanding, use my both hands for holding the object,
and it doesn't leave disturbing scratches.
Finished surface is much better than with the traditional disc sander.

Somewhat easy to make, cheap, small. Balancing takes some time. I used two days filing it to the right size and weight, but i think it was worth it. With better pre-designing i could have saved some time, but i just like to design while i make.

[DIYer]

Thanks Tuomas! We've added your Random Orbital Sander Attachment to our Sanding category,
as well as to your builder page: Tuomas's Homemade Tools. Your receipt:

Random Orbital Sander Attachment by Tuomas

tags: sander

[CharlesWaugh]

W A A A A A A A A Y C O O L ! ! !

Gotta built it!

Thanks!

[Tuomas]

W A A A A A A A A Y C O O L ! ! !

Gotta built it!

Thanks!

You're welcome.

[Tuomas]

Here is the finished random orbital bench grinder.



I tilted it 90 degrees, to get more room around the scotch brite bristle brush. Also better access to the power switch, now i can reach it what ever side i am it.



I made a dust sealing around the sanding pad, to keep dust out from the bearings.
Used toilet seat sewer sealing, just cut suitable piece from it with utility knife.

Actual guard around the random orbital sander, is made from 110 mm pipe.
I made an hole to the original guard, and then welded pipe to it.



Stand is made from 25 x 25 mm square tubing.
Feet's are surplus from old computer case project.
To prevent vibration / resonating noise, i placed suitable sized rubber plugs inside the feet's.



Bottom side of the sealing is a slot for the wrench, to allow access to locking nut of the pad.



Extra bearing for the axle of bristle brush is inside the added pipe. Pipe is shaped to fit around the grinders "neck"
I originally planned to use bigger wet stone, instead of bristle brush.. but then i noticed that i don't actually need a wet stone at all.

[Tuomas]

And here is the final pics.
Now its complete.