Failing D/A…?

[The Z'eer]

It is a palm sander, one of these https://www.toolstation.com/draper-...lIiI8nFzUp4oJ0Fh0jYaAnOgEALw_wcB&gclsrc=aw.ds

I tried it against my Erbauer D/A. I used an old piece of wood to compare the performance of both. the Erbauer operated as it should and removed a fair amount of wood on 40 grit. The same couldn’t be said for the Draper tool. Hardly any of the wood was sanded back. The Draper’s sanding disc stopped rotating and simply vibrated as medium pressure was applied

 

[The Z'eer]

That is working exactly how I would expect to work, it isn't supposed to spin at all in normal operation. Every DA I've ever used is exactly the same unless they are locked.

With no load they spin but with load the offset centre means they oscilate, all completely normal, they aren't supposed to spin when sanding.

That is working exactly how I would expect to work, it isn't supposed to spin at all in normal operation. Every DA I've ever used is exactly the same unless they are locked.

With no load they spin but with load the offset centre means they oscilate, all completely normal, they aren't supposed to spin when sanding.

Ah, I see. I thought they were supposed to spin rather than just vibrate. I didn’t realise this

 

[armalites]

Most air powered units have a random orbit but some battery/electric ones have a fixed orbit as they are driven by gears.

They are more designed as a finishing/prepping device, they aren't aimed at massive material removal.

 

[The Z'eer]

Most air powered units have a random orbit but some battery/electric ones have a fixed orbit as they are driven by gears.

They are more designed as a finishing/prepping device, they aren't aimed at massive material removal.

It just seems a little odd that it should cease to spin and merely vibrate. I’ve never known a rotary tool to do this before, in my mind it seems to go against the idea of its purpose.

 

[carbon]

The size of the orbit is doing the majority of the work. The larger the orbit the more rapid the removal of material that’s why some manufacturers offer the same da sander with different size orbits

 

[armalites]

It just seems a little odd that it should cease to spin and merely vibrate. I’ve never known a rotary tool to do this before, in my mind it seems to go against the idea of its purpose.

Not really the whole point is you get an even action across the pad, if it was rotary that can't happen because the outer edge of the pad is travelling faster than the centre. Obviously an operator can work around that.

In the old days polishing/buffing machines were rotary, they tended to be agressive and could easily burn through paint and create buffer trails. Modern units tend to be orbital as they are much more forgiving.

 

[armalites]

DAs work a bit like going on the Waltzers or Tea Cups at the fair where you have two pivot points

 

[The Z'eer]

The size of the orbit is doing the majority of the work. The larger the orbit the more rapid the removal of material that’s why some manufacturers offer the same da sander with different size orbits

Yes, when I considering a D/A I did read this purchasing several units could become expensive