Nilfisk back from the edge of Hell

Dan Jaman

20 years ago I bought a Nilfisk GM90 and the missus knocked the holy crap out of it for years. Eventually it just gave up; expiring with a shower of sparks according to her, and it got chucked in the "to be sorted" pile, along with everything else I couldn't be ar.. would eventually get around to.
So, I wondered about re-brushing it, then discovered the brushes were deliberately consumer unfriendly - no easy-replace Dyson brushes in this thing.
Having a look around I realised the Dyson DC05 / 08 motors were very close in size and one of them would fit in the Nilfisk motor housing.
I didn't want to spend too much on it, in the chance it would be a waste of money and time, so bought a cheapy ebay motor from Parts'N'Farts or somewhere.
Hah; they claimed the original price was £45, reduced to £15; yeah, right.
Still, if it lasts a year I'll be happy - sheet, if it lasts a couple of months and goes pop I won't be heartbroken, as it's just a proof of concept and I can stuff decent quality Dyson motors into Nilfisks now until the cows come home.

On with the show...

Yeah; this looks high quality. Like a firecracker...



Once the old motor's out, put a bead of silicone round the top and bottom of the base rubber bumper, to anchor the motor. It will sit there fine without this, but this is to prevent rotation.



Also as part of the anti-torque bodge, a four-some blob of PU foam is put in place.



The Dyson motor is approx 21mm shorter than the Nilfisk, so this spacer is cut 22mm to centralise it and bear down slightly on the rubber. The spacer is a piece of 28mm PEX pipe, rasped out slightly on the bottom to fit over the bearing housing with a bit of heat. I don't see that going anywhere.



Another thing had to be done - cure all the cracks in the bottom casing. This seems to be a problem with the plastic GS/GM series, as I see replacement casings still for sale - but at one helluva price. Sod that, it's ABS and can be glued or hot welded. I opted to glue it up as I had a pot of ABS / PVC pipe glue and plenty of box conduit spare.



Ugly but effective, and from normal viewing it's not seen anwyay.


I thought the old vac I was using was doing a reasonable job, but this rejuvenated Nilfisk can suck billiard balls through a straw and it's howking muck out of the carpet that I didn't know was in there. The original internal design of the Nilfisk was meant to make the most of a 900W motor, and while this cheap replacement is 1600W, and probably doesn't move proportionally more air than the old one it still manages to shift a lot, and the casing really helps it to do that effectively.
I also replaced the original hose, which had seen better days and was letting air in - with a Qualtex brand, which seems ok for now.
At the moment, there's a normal paper bag in there, but I got a packet of fleece bags which supposedly allow more air flow - will be interesting to see any improvement over and above what it is now.
Btw, the Nilfisk instructions say you cannot wash the main filter - that's a load of hooey designed to make you buy new ones. I don't know how many washes they'd survive, but it's been washed once and should be good for years yet. Years ago I bought a spare and also washed that, with no consequences.

Oh yeah; while I'm here I'd like to give a big thumbs up to the Nilfisk guy in Cork, who replaced the first motor when it was 4 years old. We'd got really careless with keeping the filters clean and it overheated. He spotted the motor was still under the 5 year warranty so fitted one FOC.
In contrast, the other guy was going to charge us the full price - so no business for him, then. To say thanks to the Cork man, I bought a few extra spares from him.

The Red Ace

great engineering job , the one thing you may need to check on is where you fitted the spacer, at 1600w the motor will tend to move and eventually pull off the mains cables, only a minor readjustment seeing as you got that far.( that motor seems very like the Henry.)

Dan Jaman

That's why there's silicone and polyurethane foam anchoring blobs. That motor isn't likely to move now. I had it in without any anchors for a day or two, just as a test, and when I took it apart again, there was no sign of rotation, after many starts, but the anchoring bodge is a just-in-case, as I didn't like to leave it like that.
The top of the spacer fits snugly into a moulded section that originally sat on the top of the Nilfisk motor.
I look upon it as a touch of Cheapskate Production Engineering, as practiced by so many companies now. Simplify and Add Lightness / Cut Cost.