Failing D/A…?

[The Z'eer]

Probably my own fault for not buying a quality brand. I purchased a Draper 150mm Stormforce D/A, already been repaired once under warranty.

I came to clean a foam polishing pad (attached to the sander) via a nylon brush. As I applied some pressure the pad began to slow down. I increased the RPM to no avail.

So, I tried pressing my fingers against the pad and sure enough the pad more or less came to a standstill, just vibration only. Please excuse my lack of experience but I’m pretty sure a D/A isn’t supposed to do this?

Thanks

 

[hotponyshoes]

Vanes in the motor stuck.
Squirt a dose of electrical cleaner into the inlet and start/stop it a few times.
Just watch out as the cleaner will blow out of the exhaust.
Repeat until it blows out clean then squirt a bit of air tool oil in to lube them up

 

[Bullet2012]

Air , battery or mains version ?

 

[stuvy]

If it’s air it could have water trapped inside

Iv had that happen in winter in an ingested building

 

[maroon]

Dunk it in some soapy water. Give it a hand crank help it along. And just run it. Then keep bliping it. Turn the pressures right up at the tank. If it's not playing ball after that it's a strip down grease up and rebuild. Thing with d/a's is they collect a lot of $hit. dunking them in a bucket of water when using them helps. Assuming it's air. Don't start running electric sanders in buckets of water.

 

[Turbo]

When you're finished with a rotary air tool like a DA sander you should add a few drops of oil to the inlet & run the tool for a few seconds. No matter how good your air system is you will get some moisture inside the tool during use & if you don't lube it afterwards the water will cause problems when you store it damp!

 

[The Z'eer]

Vanes in the motor stuck.
Squirt a dose of electrical cleaner into the inlet and start/stop it a few times.
Just watch out as the cleaner will blow out of the exhaust.
Repeat until it blows out clean then squirt a bit of air tool oil in to lube them up

Many thanks for the suggestions I’ll give that a try tomorrow

 

[The Z'eer]

Air , battery or mains version ?

Pneumatic

 

[The Z'eer]

If it’s air it could have water trapped inside

Iv had that happen in winter in an ingested building

I’d doubt that, there’s no moisture in the line. It’s breathable air for the air fed mask that supplies the tools. Four stage filter.

 

[The Z'eer]

When you're finished with a rotary air tool like a DA sander you should add a few drops of oil to the inlet & run the tool for a few seconds. No matter how good your air system is you will get some moisture inside the tool during use & if you don't lube it afterwards the water will cause problems when you store it damp!

All the tools in the workshop are kept around 50% relative humidity, a dehumidifier does that

 

[stuvy]

I’d doubt that, there’s no moisture in the line. It’s breathable air for the air fed mask that supplies the tools. Four stage filter.

Just read my own reply uninsulated building

 

[not done it yet]

I’d doubt that, there’s no moisture in the line. It’s breathable air for the air fed mask that supplies the tools. Four stage filter.

I expect if should have an in-line oiler, so no longer breathable air?

 

[Turbo]

All the tools in the workshop are kept around 50% relative humidity, a dehumidifier does that

You still have to lube the tool before & after use, you can't expect a tool to run at a few thousand rpm without lube! All it takes is a few drops of light hydraulic oil into the inlet before attaching the hose.

 

[hotponyshoes]

Be careful what oil you use if it's for paint prep as particals of it will blow out of the exhaust and all over the panels that need painting.
Proper air tool oil wipes off ok when you prep the panels.
If you have a big drum of something else maybe try wiping a trace of it off of something before sticking it in the da as some types of oil just smear around or soak into filler/primer

 

[armalites]

Something nobody has mentioned, unless an air DA is in scurf/locked mode the pad won't spin once there is pressure on it that's the whole point of them. This is completely normal in orbit mode they will spin like a goodun with no load but that stops as soon as there is any load.

Some of the palm ones don't have locking mech

It sounds like yours is working completely normally to me.

In my experience even really cheap air DAs will run years even when abused

 

[carbon]

The rupes skorpio that I have doesn’t spin much at all when away from a panel and not at all when flat on a panel.
The recommended lubrication for that is 2 to 3 drops of oil in the inlet every 50 hours of run time

 

[The Z'eer]

You still have to lube the tool before & after use, you can't expect a tool to run at a few thousand rpm without lube! All it takes is a few drops of light hydraulic oil into the inlet before attaching the hose.

It’s been fed with the required amount of oil, there’s no issues there.

 

[The Z'eer]

Something nobody has mentioned, unless an air DA is in scurf/locked mode the pad won't spin once there is pressure on it that's the whole point of them. This is completely normal in orbit mode they will spin like a goodun with no load but that stops as soon as there is any load.

Some of the palm ones don't have locking mech

It sounds like yours is working completely normally to me.

In my experience even really cheap air DAs will run years even when abused

I don’t think it’s working correctly. I used a marker pen and marked the edge of the sanding disc to see if it’s spinning properly.

Squeeze the trigger when the sander is in the air and it spins freely, no issues. Place it on a panel and apply light pressure, appears to slow the RPM. Use medium pressure and the disc ceases to rotate and simply vibrates.

 

[carbon]

Is it a palm sander? If it is nothing drives the pad, it’s mounted on two bearings that are offset from the centre of the axle that is driven. See this Parts list

 

[armalites]

I don’t think it’s working correctly. I used a marker pen and marked the edge of the sanding disc to see if it’s spinning properly.

Squeeze the trigger when the sander is in the air and it spins freely, no issues. Place it on a panel and apply light pressure, appears to slow the RPM. Use medium pressure and the disc ceases to rotate and simply vibrates.

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.