Shredder capacitor

[Chris J Dixon]

For some time I have had, and been very pleased with, an Alko SP5000 Silent Power Electric Garden Shredder

It has a reversing switch, to deal with clogging.

Recently, it has sometimes stalled on starting, and the direction of running seems random, and unconnected with the position of the reversing switch.

The exploded drawing shows what looks very much like a motor capacitor which I am guessing has failed.

Further investigation is currently blocked, as one of the screws in the top moulding, which is the first step to dismantling the machine, has a one way head, looking rather like this:

and it fits in a recess.

I have seen rather expensive removal tools, with a couple of pins, but the reviews are, at best, mixed.

The simplest, and crudest, solution is the attack the screw head with a Dremel cutting disk, and attempt to cut a sharp enough edge to engage a screwdriver. This will inevitably cause damage to the surrounding plastic.

Has anybody else had to deal with this?

Chris

[John Rumm]

A left handed drill bit can work wonders (quite often it will free the screw by itself, if not then you could try a screw extractor once you have a hole)

[Adrian]

Since it's clearly outside warranty and you'll not be worried about any future manufacturer support, the only real problem would be one of cosmetic damage. I'd have thought a well-used garden shredder would already be a little, umm, "pre-loved" in appearance anyway.

I'd just do it.

But have you tried drifting it with a small screwdriver or chisel or similar, first? I can't imagine it's particularly tight. Might just come.

[Tim+]

What bastards! You could perhaps try drilling two small holes (one in each "ramp") to then allow the use of a modified screwdriver.

Tim

[Dave Baker]

Weld a small nut to the top of it.

[Antonius Liberalis]

If the screw is close to an edge you may be able to Dremel through the shank along the join-line.

If you have [access to] a mill and the part is sufficiently robust you can mill the top off the bolt.

If you have a drill press you might try putting a pair of holes in the flats and making a pin-tool from a screw-driver (though the "like-this" part you link to is stainless and hence likely to be tricky to drill).

Extremely unlikely is a through-hole - but if so you could drill through from the other end; often this will make the screw unscrew.

Tools that won't come apart are for girls.

[Chris J Dixon]

No access to the join face

I haven't, but this would also take off the surrounding recess, and I was rather hoping to fasten it together again afterwards.

I suppose it would just about possible to clamp my bench drill so that it would overhang the shredder. The screw head is about 6 mm dia, so the holes would by tiny and, as you say, not easy to execute.

Access is only from above. The screw is in a recess, and close to a raised surround, making it pretty tricky to get at. Removing one of the ordinary screws in the symmetrical location reveals it to be a self tapper about 20 mm long.

Chris

[Antonius Liberalis]

You say it's about 6mm, plunge mill with a 1/4 flat-bottomed cutter.

(For extra points hand-grind a left-handed one.)

[Chris J Dixon]

I know of these.

I was able to remove one of the ordinary screws in the symmetrical location and found it to be a pan head self tapper about 20 mm long, with a head roughly 7 mm dia.

I'm not sure screw extractors of this type would have enough metal to get a grip on. It is also interesting that a significant proportion of the reviews rated it 1 star, not recommended.

Chris

[Tim+]

How about a diamond tipped screwdriver blade? Apply a lot of pressure and who knows, you might get lucky.

Not too expensive either.

Tim

[newshound]

I agree, a "chisel" can often be quite effective. I would vote for that rather than a screwdriver since it will definitely be through-hardened.

I have one which looks a bit like a manual centre punch, except that the final shank is ground to a square section and instead of coming to a point, an angled "flat" is ground on it so that one corner serves as the sharp point which you use to attack the screw head in a tangential direction.

[John Rumm]

Have you considered trying to over-tighten it such that you strip the threads from the hole?

Then using a slightly larger diameter self tapper to replace it. (or filling the stripped hole with epoxy etc).

[Chris J Dixon]

That's an interesting thought, and as you say, cheap enough to try.

Chris

[Huge]

Or you could do what I did with the charger for my B&D electric screwdriver; lose your rag and wrench the thing apart, hot gluing it back together once electrically repaired.

[fred]

In article , Chris J Dixon writes

I may be missing something but can't you just drill the head off?

Centre punch the middle of the head and drill with the largest dia drill that will fit between the lobes. Even if the shank isn't parted by the time you are through the head then it will be seriously weakened and turning the screw so as to tighten it should shear it off.

Once it is apart, remove the shank by gripping the remnants in pliers or mole grips and replace with a plain self tapper.

Next time Lidl/Aldi have an offer on, buy a set of screw extractors ;-)

[harryagain]

I have a similar machine (Alko3500) The reversing switch (adjacent to the on off switch) is a bit dodgy on mine. (Poor design) I have had to fiddle with it a couple of times.

Also there is an overload device that reverses the machine if it jams. This might cause your problem.

If the capacitor was faulty, it wouldn't run at all, it would just hum.

[Chris J Dixon]

It might indeed be the switch, rather than the capacitor, but to check this out, I still appear need access to the same area, which is blocked by the security screw.

What precisely did your "fiddling" consist of?

I know that, but that doesn't seem to be the problem.

At the moment, the symptoms are that sometimes it just hums, and has been known to blow the fuse in this stall condition. Sometimes it starts OK, sometimes it starts in the reverse direction. The direction is no longer influenced by the reversing switch.

Once running it is perfectly OK.

Chris

[Chris J Dixon]

I possibly might, but is probably the last resort.

I'm not convinced that there is enough material to get a good grip, nor that extractors are particularly successful for this kind of situation. Am I alone in my skepticism?

Chris

[harryagain]

On most electric motors,the start circuit is switched out once the machine is running.

There is a stupid sort of cam operating a micro switch for reversing. The switch was OK but the cam was semi seized and bunged up with crap. Clue was reversing switch was stiff and didn't rotate as far as normal Cleaned up and WD40 fixed it. So far at least. But still feels a bit dodgy when I turn it. V.poor design I would say. The cover on mine just has pozidrive head screws, no security screw(s). It's about four years old.

[Peter & Jeanne]

Simple solution - just drill it out - no need to use a bench one either. Start off with a bit that is a snug fit in the recess to indent the culprit centre - drill through the head with a bit of similar size to the bolt. finish off with same larger bit if necessary.

Pete