Hover Mower Blade Removal

[Wingedcat]

Hi, I've got a Black and Decker (approx. 20 years old) electric hover mower with a metal blade that I want to remove as it has got badly bent. However removing the blade is proving a little difficult.

The blade is held in place with a plastic (nylon?) bolt. I've tried using the classic "Flymo" spanner (same size) on it but it broke (!). Then I tried doing the same with an different spanner turning in a clockwise direction. Logically, the bolt undoes clockwise, due the direction of rotation of the motor, but I'm not sure if this is actually the case. I didn't break a second spanner!

Then I tried mole grips on the bolt, and a length of scaffold pole over the blade, and squeezed the two together. This resulted in the blade turning on the shaft, and the bolt staying put.

What do you reckon I have to do to remove it? I am reluctant to wedge anything in the motor itself, as the casing is plastic, and I suspect it would just crack. I *could* try holding the plastic fan thing (I believe it is known as an impellor) just under the blade, but this doesn't look too strong either.

I'm thinking about just hacksawing off the bolt and dealing with the aftermath later. What do you reckon?

Thanks

Luke

[Preston]

Turn it the right way - which is anti-clockwise.

[chudford]

My Flymo undoes anticlockwise.

[Scabbydug]

There's a normal steel bolt head embedded in the nylon nut you describe, cut the nylon away and use a normal ring spanner.

[Jules]

Can't you see any of the threads in order to verify that?

If the plastic bit is just covering a regular nut as someone else said, ditch the plastic and then try heating the metal nut with a blowtorch; sometimes doing so one one of two components that are stuck together can work wonders...

(obviously heating the plastic nut won't get you very far ;)

cheers

Jules

[Wingedcat]

Hmm yes but that won't help, as it will still end up rotating the shaft as I have nothing to brace against.

See:

I am able to rotate the bolt with mole grips, but have nothing to counter-hold to prevent the motor from turning too.

[TheScullster]

"Wingedcat" wrote

Hmm yes but that won't help, as it will still end up rotating the shaft as I have nothing to brace against.

See:

I am able to rotate the bolt with mole grips, but have nothing to counter-hold to prevent the motor from turning too.

----------------------------------------------------------------- In these situations it is usual to try and use the inertia of the secured object. That is hit the free end of the spanner very sharply to undo the nut (making absolutely sure you know which way "undo" is of course). This becomes less effective as the stationary part becomes easier to turn IYSWIM.

Phil

[Stuart Noble]

The usual way round that is to hit the grips with a hammer, one short sharp whack. Hopefully the thread turns faster than the motor for an instant. I'll add my hunch that it should go counter clockwise. I've never known one that didn't, but maybe the manual will confirm that.

[R]

Stand the unit on its side and use a wedge of wood between the blade and the case or slide a tube over it and wedge it in the ground before undoing the bolt in a normal direction

[Wingedcat]

No good because although the blade is held still in the manner you describe, the bolt turns with the motor with the blade spinning on its shaft.

[Dave]

As another poster said, hold the blade with whatever and whack the spanner/mole grips with a heavy hammer, putting the mole grips/hammer back into horiziontal position and you should get enough purchase to get the fastener loose and out with a few whacks.

Being a mower, it is likely that there has been a build up of rust on it. You could try using WD 40 on it 24 hours before though.

Have you got a paint sripper heat gun? You could try heating it up with that until you smell the plastic? Try using that as well.

Dave

[Harry Stottle]

It sounds like you need is a 12v impact wrench, the sort sold for removing car wheel studs, and appropriate socket.

[R]

So it's out out the angle grinder then

[Wingedcat]

Yep, that's what I did, literally, in the end. I cut off the plastic (nylon) with a Stanley knife, ground off the bolt head with an angle grinder, then could lift away the blade and the impellor. I actually straightened out the blade and then sharpened it up withe the angle grinder but the extremely friendly proprietor of the local "sells absolutely everything" ironmonger persuaded me a new blade and a new bolt. Put the whole lot back together and it's as good as new (I hope!!!). Total cost =A312.

Luke

[Chris J Dixon]

Glad you managed it. Just for completeness, how did you remove the remains of the previously stuck bolt in order to fit the new one?

Chris

[Harry Stottle]

Yep, that's what I did, literally, in the end. I cut off the plastic (nylon) with a Stanley knife, ground off the bolt head with an angle grinder, then could lift away the blade and the impellor. I actually straightened out the blade and then sharpened it up withe the angle grinder

Don't risk using a straightened blade in the mower. I did that once for a neighbour and the blade broke whilst in use, propelling the snapped off straightened part through the plastic skirt, just missing her foot.

[Wingedcat]

AH! Well, once I had "released the pressure" so to speak (by cutting away the head of the bolt), I was able to hold the impeller with my bare hands and turn the remains with a pair of mole grips fairly easily.

[Stuart Noble]

In which direction? :-)

[Wingedcat]

Put the whole lot back together and it's as good as new (I

Anti-clockwise! (as I think others may have suggested). Some websites, mostly American, suggested LH thread was a possibility, but in the end no, it was standard anti-clockwise to undo.

Luke

[gregknill]

After battling for 3 days with the stupid Flymo spammer, I eventually put the machine upside down in the sun Then sprayed it liberally with yet more WD40. Then I chocked the blade with a big chunk of wood, and got The longest bar-clamp I have (about 1m). After an hour In the sun I used the clamp as a spanner, and it came Off without effort. Greg