Thread: Metabo SPA 1101

Sorry I can't help with the removal of the impeller but I can tell you that a straight sided impeller like that is not going to be able to generate much pressure so it will have poor flow characteristics once any ducting or filters are added.

You could try filing away the blade that it touching the impeller but just remove enough so it does not touch. If you remove too much you might unbalance the impeller which could lead to bigger probe.

Thank Bob
The plate the blades sit on is out of level too, so there may be problems with balance anyway. The problem is that the high spot is under the plate. I have been progressively wearing it down with a bent hack saw blade.

As far as the flow characteristics, I would have thought that it will be sufficient as it is sold as a dust extractor If I can get it too spin without the rattle it may be a goodun for the price of a couple of dust bags.


TT

Originally Posted by Twisted Tenon

As far as the flow characteristics, I would have thought that it will be sufficient as it is sold as a dust extractor . . . . . . ..

Unfortunately no, don't forget that all Saw dust extractors less than 3HP and even some 3HP DCs have flow rates that are less than satisfactory and at least they have the right sort of impeller for wood dust.

There is a bit of a difference between moving flour dust and moving sawdust. Flour dust is so fine its like like pumping air which is why they have used that sort of low pressure impeller whereas sawdust with chips in it generates a significant back pressure. No matter what it's pumping it's flow rate will be too low for a viable sawdust extractor.

Thanks Bob
I didn't know that. This is what I looked up when I heard about it from a friend.

TT

Originally Posted by Twisted Tenon

Thanks Bob
I didn't know that. This is what I looked up when I heard about it from a friend.
TT

Thanks for the link, now I can really analyse it properly because nearly all manufacturers fudge their specifications, especially so on dust extractors.

These are the 3 critical specs to examine.
Max Vacuum 1300 Pa
Max.Volume flow 842 m³/h
Rated input power 0.37 kW


If the claimed 0.37 kW is correct (which it often isn't) as I said in my previous post this amount of power is simply insufficient for any half reasonable dust extraction.

1300 Pa is 5.22" of Water Column pressure. A normal 1HP DC generates about 6" of WC so it is very unlikely that a half HP with an old impeller design will generate 5.22".

The claimed 842 m³/h (= 496 CFM) will be for the impeller alone ie no hose and no bags. My experience with testing various DCs is the way the manufacturers do their air flow measurements is incorrect by at least a factor of 2.

Even if the 1300 Pa pressure rating was correct, it is physically impossible at this pressure to move more than 300 CFM through a 4" hose.

In reality that DC is unlikely to generate more than 4" of WC, so by the time the bags and hose are added the flow will be down to around 200 ~CFM. This will still pick up some chips but will fail miserably at catching the dust especially from a drop saw as shown on the Metabo website.

Thanks for taking the trouble for replying Bob.
Makes you wonder though. The asking price for the Matabo is $609.00 and for a 2 HP Hafco model you pay $297.00. It's a case of buyer beware

Originally Posted by Twisted Tenon

Thanks for taking the trouble for replying Bob.
Makes you wonder though. The asking price for the Matabo is $609.00 and for a 2 HP Hafco model you pay $297.00. It's a case of buyer beware

Yeah this is pretty common and depressing - tradies working for businesses often don't worry about price as the businesses can just pass it on to me and you.

Originally Posted by Twisted Tenon

I've recently acquired this dusty for next to nothing. It came out of a food processing factory and was used to extract flour dust off a production line. It also seems to have been exposed to a lot of moisture (steam I would think). It has no bags but that is not the problem. When I turn it on there is a loud rattle coming from the base.

After taking it apart it seems to me that one of the vanes is the problem. I've taped the vane that is causing the problem the two pics shows where it is snagging. I know it is this vane that is the problem and not the base of the cowl by a process of elimination.
The vane base appears to be bolted to the main shaft but I can't get a socket into it.

Any suggestions on how to get the base off would be appreciated.

TT

IMG_0100.jpgIMG_0111.jpgIMG_0103.jpgIMG_0119.jpg

A long series socket or normal socket with an extension should get onto that nut, spark plug socket might be worth a try 3/4" if I remember right, also a hex socket will be better if the nut is corroded as it looks, also if the bolt won't move give the head of the nut a good hit with a heavy punch and hammer, usually helps to loosen things and get them moving.


Pete