Mirka DA sander keeps stalling?

[julianf]

I have a mirka ROS 650CV

Ive just been trying to use it, and it keeps stalling, just like its run out of air (which it has not)
If i stop momentarily, it will rev up again, then stall again.
If i spray a load of oil down the air line, that makes it better for a short while.

When its stalled, some air is coming out of the 'exhaust' but not loads.


I purchased the unit used, and have had it a while, but ive always thought its speed to be a little intermittent, so i wonder if that is connected?

I think that, to strip the unit down, you need a special tool, which i dont have.

Any ideas?

 

[armalites]

I have had air couplings give similar result on an impact gun. I replaced the fitting on the airline not the tool and things improved. The other thing I did was give the air exhaust a shot with a blow tool. I think mine was a little blocked as it had a filter in it. Again that made a difference.

 

[julianf]

Thank you.

I did put a blow gun / duster on the line, to check, and the flow seemed no different to normal. Very subective, but i seemed to be able to blow stuff across the floor with equal strength to normal!

Ill try direct from the compressor and see if that makes a difference - take out the air line all together.

The connectors i have are not pcl, but the higher flow ones - T25, i think theyre called?

 

[armalites]

Sorry what I mean is blow the exhaust on the tool itself

 

[mike 109444]

Sounds like the vanes are sticking or worn (think hydro vane!). This would allow air past and out the exhaust and loosing power.

 

[Wallace]

Does it have a speed control?

 

[julianf]

Im using it direct from the compressor now, and its running, but does not seem to be at full whack.

Ill try it on the airline again tomorrow, as it may just be co-incidence - ie it may have started (almost) working again. Ive been using it on the same airline previously without issue.

And, no - no speed control.

 

[Ruffian]

Air freeze because of the temperature,

 

[frank horton]

just get a cheapie off the net, then bin when it goes wrong.......if ur doing body work it's a bit naughty to use oil or WD40 for lube in it because of the mess/painting.....but what can ya do.......
I got a new one a freebie but don't use em anymore, bought a Makita orbital.....quieter than the air types and no compressor running.......also save's on elec, no oil needed.....!!!!!!!!
frank

 

[gaz_moose]

^^what this guy says^^
air powered DA's are mega hungry. some cheap light electric palm DA and skip it when it blows up.

 

[julianf]

Thats kind of what i was thinking -

When i purchased it, i asked on here, and was told to get the mirka, so i did. Ive never been all that impressed, as my compressor is 3kw, and runs all the time when the sander is going - i really dont feel like i have 3kw of sanding power though!

It does give a good finish, and is light, and easy to move about though.

 

[Ruffian]

For a da you would want more than 3kw,
As will rinse air.
Most recommend big compressor' for bodyshop's
I.e hydrovane

For anything hobby would go electric now.

 

[julianf]

Ive not had to stop due to lack of air before. The compressor runs all the time but, again, ive done long job, and its kept up. There is no change in power from when i start (with a full tank) to when i stop.

That's not my current issue anyway. Well, its not really my issue at all....

 

[brightspark]

I have a couple of da that are made in japan good quality and don't use a lot of air. the compressor has 100 percent duty cycle and can keep up with them no probs it will run 24 hours a day its an air brake pump of a wagon 14cfm

 

[Wallace]

Lists a speed control on one of the exploded views and on this site Link. Is the inlet air filter gauze clean?

 

[julianf]

I'll take a small video tomorrow and see if I can't post it up.

 

[Wallace]

Meant to add on my earlier post about the mufflers possibly being dirty or partially blocked.

 

[armalites]

Meant to add on my earlier post about the mufflers possibly being dirty or partially blocked.

This is exactly what happened to my impact gun, it has some coarse foam material in the exhaust. I think it got clogged with oil.

 

[Turbo]

I have a Lidl DA sander & my 3hp compressor is just about able to feed it but it's ok as I run out of energy long before I run out of air!

 

[julianf]

To follow up this thread -

I spotted another, boxed, mirka 650 sander on ebay for not a load of cash, so purchased that.

The only thing ive used from the new kit so far is the spanner that is needed to get into the inside of my old one...

Full of junk (not that that would have stopped it though) so i cleaned all that out, and filled the unit with kerosene (which i know is too thin for lubrication, but i wanted it for cleaning).

Ive not actually got to the vanes (as in to see / touch them) but i assume the kerosene probably worked its way down there.

Also took the muffler out - that was gummed up also.

Anyway, the original one now runs better than it ever has done in my ownership (i purchased it used) - proper fierce action.


Thank you to all those who replied on this thread.