Home-made passive sander

[Rodpr]

Many thanks for all the really helpful responses to my appeal for a light and simple way to power small sanding discs for bowl finishing. I think I have decided to try using a passive sander, with my cordless drill as back up for the problem areas.

I bought a set of 8 sanding arbours, with pads because, at less than £2 each it didn't seem worth the hassle of making my own. When they arrived, one of the arbours was missing its nut and this got me thinking that if I could make up a spinny holder for one arbour I wouldn't need the others. I could just unscrew one pad and screw on another, keeping one for each of the grits I use

 

[Rodpr]

I had a rummage in my 'come in handy one day' drawer and found some bearings and a piece of bushing that fitted nicely in them. I dug out a bolt with a thread that would fit in the sanding pads but it was a bit too big for the bushing so I ground it down by spinning it in my drill against my grinder. First I ground the end down to the right size, then I ground the rest down until it would fit in the bushing. I used a file to clean it up a bit.

 

[Rodpr]

Now I had a threaded shaft that would fit in the bushing that would fit in the bearings but I needed a way to secure it so I got out my tap and die set which I inherited from my father-in-law and found a die that would fit. I have hardly ever cut a thread on or in anything but this went surprisingly smoothly

 

[Rodpr]

I happened to have a scrap piece of ply just the size that I needed so I cut out a couple of 'p's following a design I saw in YouTube video. As I don't have a first er bit the right size to drill holes for the bearings I decided I would cut these on my lathe. I drilled centre holes in the 'p's and in a scrap of cut off tenon. I hammered a bit of dowel into the scrap tenon, chucked it up and tried it up before gluing on one of the 'p's with hot glue. Then I was able to rough out the hole before sneaking up on a fit with my 1/4" spindle gouge.

 

[Rodpr]

The lathe makes an excellent press for fitting the bearings nice and tight. Then I fitted the bushing and spacers before gluing the two 'p's together. Just time for lunch while the glue sets!

 

[Rodpr]

Turned a handle from a piece of beech (recycled from a sofa frame), shaped the ends and fitted a pivot. Here it is all put together. I added a spring to help avoid excessive pressure while sanding and I am going to see if I can find a couple of big washers to cover the bearings and keep dust out

 

[Rodpr]

Here it is in action

 

[Richard_C]

Excellent, much fancier than my chair castor plus bit of mouse mat* version. There was an earlier post saying that power is best for spot sanding of tear out, which it can be. I always end up using a SHF** and abrasive with the lathe off for that, you can go with the grain then finish off with the passive sander.

* left over from when mice had balls

** SHF = standard human finger

 

[Rodpr]

Thanks Richard. I can see this being good for outsides of bowls and top of insides with a mix of cordless drill and shf for the lower insides. I now save up all 'high density' packaging pieces and cut them up to make sanding pads - avoids cooked thumbs!

 

[David Lloyd]

I did a similar thing, but I used a chunk of brass that didn't need bearings - reducing the size of the carrier - and bolted it to an old handle off 'something' that I had under the bench. I'll take a pic tomorrow.