What motor would I need?

[Mike Krall]

Hi everyone,

I am by no means an electronic expert so don't kill me

I'm trying to figure out what kind of motor I would need to mimic the actions of a palm sander where it orbits in 360 degrees, but with more area coverage then the actual tools provide. So for instance a palm sander only vibrates like 1/4" in any direction. I need to do that over a couple of inches.

Originally I was going to make an air powered piston I guess the correct term is double acting cylinder but I can't see to do that with the exhaust of a shop vac vacuum.

Anyway the goal is to a very low tech object, a flat micro fiber mop into something more high tech and 'automated'.

I would appreciate any help or direction you can give. Thanks!

 

[MaxHeadRoom78]

A palm sander uses a Universal motor for high rpm.
Make a rotary to linear mechanism to suit the stroke you need.


Max.

 

[Mike Krall]

A palm sander uses a Universal motor for high rpm.
Make a rotary to linear mechanism to suit the stroke you need.


Max.

Thanks Mr HeadRoom!

I don't fully understand that so let me research it

Edit: That's going to produce just side to side motion? It looks like the slider is held from moving in any direction other than side to side.

 

[shortbus=]

A palm sander uses an offset bearing to drive the pad. the offset is half of the total movement, 1/8" on your 1/4" example. If you've used one you know how much/bad they vibrate. Can you imagine the vibration from one with a 1" or more offset? I'm betting it would be on the verge of uncontrollable. Maybe a dual action sander is what you need? Similar to a palm sander but with a larger pad. Just one of many links - https://www.eastwood.com/6-dual-action-air-palm-sander.html

 

[strantor]

A palm sander uses an offset bearing to drive the pad. the offset is half of the total movement, 1/8" on your 1/4" example. If you've used one you know how much/bad they vibrate. Can you imagine the vibration from one with a 1" or more offset? I'm betting it would be on the verge of uncontrollable. Maybe a dual action sander is what you need? Similar to a palm sander but with a larger pad. Just one of many links - https://www.eastwood.com/6-dual-action-air-palm-sander.html

I just dissected an orbital sander recently and I was expecting to find just what you described; an offset bearing. Guess what I found?
An offset weight. Yep, that's it. motor shaft with an offset weight on the end of the shaft. A really, really big cell phone vibration motor. It's not actually moving the pad in relation to the palm piece. The whole thing just rattles away in you hand until the bearings or your hand joints fail. In my case it was the bearings.
This was a cheapo Black & Decker sander, maybe nicer ones are built better.

 

[Pommie]

Good quality ones move the pad and are balanced to reduce vibration. Maybe if you describe what you intend to use the device for we'll be able to better advise.

Mike.

 

[Mike Krall]

A palm sander uses an offset bearing to drive the pad. the offset is half of the total movement, 1/8" on your 1/4" example. If you've used one you know how much/bad they vibrate. Can you imagine the vibration from one with a 1" or more offset? I'm betting it would be on the verge of uncontrollable. Maybe a dual action sander is what you need? Similar to a palm sander but with a larger pad. Just one of many links - https://www.eastwood.com/6-dual-action-air-palm-sander.html

This is what I'm looking to put into motion:

**broken link removed**

I did a test with a palm sander attached and it worked well. You may be right with a 1" off set being uncontrollable. I think they have 'sheet' sanders that have a lot more movement, I'll have to try one of those.

A dual action sander wouldn't work as those spin around in a circle, correct?

 

[Mike Krall]

I just dissected an orbital sander recently and I was expecting to find just what you described; an offset bearing. Guess what I found?
An offset weight. Yep, that's it. motor shaft with an offset weight on the end of the shaft. A really, really big cell phone vibration motor. It's not actually moving the pad in relation to the palm piece. The whole thing just rattles away in you hand until the bearings or your hand joints fail. In my case it was the bearings.
This was a cheapo Black & Decker sander, maybe nicer ones are built better.

Do you have a picture you could share please?

 

[Mike Krall]

Good quality ones move the pad and are balanced to reduce vibration. Maybe if you describe what you intend to use the device for we'll be able to better advise.

Mike.

Well this is the platform:

**broken link removed**

for which I want to put into motion. I believe it can effectively clean but just moving left to right a few inches. It could clean even more effectively if it mimicked a palm sander's motion but only if it moved out in a bigger circle.

More or less it needs to mimic this:

which as far as I can tell is like a palm sander.

 

[strantor]

Do you have a picture you could share please?

unfortunately I threw it all away except the stator

 

[shortbus=]

I just dissected an orbital sander recently and I was expecting to find just what you described; an offset bearing. Guess what I found?
An offset weight. Yep, that's it. motor shaft with an offset weight on the end of the shaft. A really, really big cell phone vibration motor. It's not actually moving the pad in relation to the palm piece. The whole thing just rattles away in you hand until the bearings or your hand joints fail. In my case it was the bearings.
This was a cheapo Black & Decker sander, maybe nicer ones are built better.

Don't know about a B&D. I have a couple of Porter Cable ones. And one that belonged to one of my great grandpa's, he was a cabinet maker. It was worn out and I rebuilt it, thats how I know about the offset bearing. Like this but older -
https://www.portercable.com/Products/ProductDetail.aspx?ProductID=24407