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repairing a disc cutter

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sunnybob

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My makita disc cutter (angle grinder, whatever) has been tripping out the mcb for a while now, but as I usually use it at the end of a 30 metre extension, Its been nothing more than a nuisance.
Yesterday though it tripped three times on startup, and when I moved it into the woprkshop to remove the extension lead element it still wouldnt work. So I had to divert from the job in hand to find out what was wrong. Its only three years old and not used often, and also doesnt get thrown around, so I was concerned it might be a fatal internal flaw. The plug is moulded, so that was the first thing to cut off and replace. No difference.
Had to take the machine apart just to get to the other end of the cable. No power. Good, its not the machine. Found the cable grip had crushed the cable (as always, screws too tight). Cut the cable back and remade the connections. No power.

So now I had to test the mains lead with the ohmeter. neutral fine, live open circuit. I spent a long time going over every inch of that cable and it wasnt even nicked, let alone crushed, but the live had a break somewhere.
Replaced the cable, and all is well again in disc world.

Dont always scrap a tool just because it stops working. :cool:
 

Phil Pascoe

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I used to test broken down vacuums before they were sent for repair - nine times out of ten the lead had a break somewhere, usually a couple of inches from the cable grips at either end so it wasn't obvious until it was tested. Quite often I couldn't be bothered to get the tester out and just cut off the ends of the flex and rewired them as a matter of course.
 

sunnybob

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Slow day today, so I've just stripped the cable to see.
8 ft long factory cable, 30" from the plug and the live wire is gone for about an inch, and the neutral wouldnt have lasted another 30 seconds. Not a scratch, dent, or nick on the outside sheath.
 

disco_monkey79

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Congrats on fixing, rather than binning - always satisfying. My ex's dad gave me a vintage B&D drill (orange casing - anyone know what era that was, just out of curiosity? '70s?) that had sat unused for many years as it would intermittently cut out. The cause? Sawdust/crud in the trigger meant electrical contact was hit and miss. All it had needed was cleaning.
 

AndyT

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Yes, thanks for passing on this useful, non-obvious experience. Information to file away until needed.
 

Terry - Somerset

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I seem to recall my father also has a cream (or grey?) and orange B&D back in the day when DiY power tools were drills only.

I think it had a cast metal casing (aluminium or mazac?). Probably from mid 1960s!
 

Trainee neophyte

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My router started playing up a few years ago - turns out mice had eaten the insulation off the mains lead. A bit of gaffer tape and we're good to go. It's still on my list of things to sort out, one day...
 

sometimewoodworker

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Slow day today, so I've just stripped the cable to see.
8 ft long factory cable, 30" from the plug and the live wire is gone for about an inch, and the neutral wouldnt have lasted another 30 seconds. Not a scratch, dent, or nick on the outside sheath.
Was it “carp“ copper coated aluminium cable? That is not uncommon in cheap Chinese products.
 

Trainee neophyte

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No no no no.
Gaffer tape is NOT an insulator!!!!!!!!
Replace the cable, for the sake of your family.
I said "gaffer tape" for effect, but I did actually use electric insulation tape, I promise. Just too many letters to type.

Is it windy at your house? I have a hurricane today :) I am entertaining myself by watching the chickens get blown around the valley.
 

owen

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I've replaced loads of leads like this at work, especially on sds drills and breakers, I think it's where the lads are using the cable to lift up or put the tools down. I've told them not to do it plenty of times but they still do.
 

Cooper

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Unlike most of you I'm a bit of a bodger, though I had success with a similarly frustrating problem. I was given an old SDS drill so I could dig up a lamp post in the garden. The drill packed in and after checking the leads, brushes and internal connections I couldn't trace the issue. I was about to bin it when I thought I'd dismantle the motor. I found that a flint had been drawn into the casing and cut one of the fixed coils through couple of the loops. I soldered a couple of patches, wrapped with tape, then reassembled. It worked when I tested it. Expecting my repair to shake apart I didn't have much hope of it finishing the job. But I was able to work for several more strenuous hours and got the post out. The drill is still working.
 

sunnybob

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No, its all copper, original factory lead. i dont misuse the tools, they dont get thrown about or even stood on. I was surprised because the cable grip in the machine itself was way over tight and I thought I had fixed the problem by cutting the lead back.
One of those mysteries of life.
 

sunnybob

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I said "gaffer tape" for effect, but I did actually use electric insulation tape, I promise. Just too many letters to type.

Is it windy at your house? I have a hurricane today :) I am entertaining myself by watching the chickens get blown around the valley.
Insulation tape is NOT suitable for an outside repair to a cable. My original plea for you to return to sanity still stands.

Exact opposite on wind. Absolutely none. Just drove past a big wind farm and they are all stock still. Still well above average temps, 36 at 2 pm. I'm still using the pool, Unheard of in mid september.
 

sunnybob

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No,,,,, a NEW cable is the correct thing to use, sheesh. 🙄
Apart from anything else, it will cost you less than a roll of self amalgamating tape, and you wont get anywhere near as sticky.
Is cuts and cracks on your mains leads the equivalent of notches on a handgun? Seems like.
Ask BM101 how many knots he has in his climbing ropes.
 

novocaine

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I can answer that for BM. one knot. 3 if he has to tie off.
3 core 1.5mm is something like 2 quid a metre. doesn't seem worth it for a repair.

SB, I've had similar with tools I'd say I take pretty good care off, it's normally because I've overbent the lead at some point, with stuff like grinders it often were I've been lay on my back underneath something and the cable has snagged.

as already said, pennies to repair, not worth the tape.
ask my neighbor though, who's hedge trimmers have a cord that looks like a scouse nun rolling down a hill (it goes orange, black, orange, white, orange black, white etc.) though and he might disagree. I don't reckon there is even a block underneath the tape, I think he's just twisted them together. I don't lend him tools. :)
 

sunnybob

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At the start of the year, my crazy german neighbour imported a 1959 willys jeep from india. It was a mahindra made under license. but after 50 years of indian roadside repairs, the wiring was, shall we say politely, "shot".
Every wire circuit had extras, twisted together and taped. The horn wire, from the floorboard to the top of the steering wheel (about 3 feet in length), was four separate wires twisted together. Even the fuse box had every single wire twist and taped at the rear. Most lights only worked while the jeep was being shaken.
I re wired it for him from head to toe. He was most impressed when he managed to drive it for 60 miles without a breakdown.
 

disco_monkey79

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I seem to recall my father also has a cream (or grey?) and orange B&D back in the day
Sounds like we're describing the same thing. I hope this link works - a bit of googling turned up the Argos Spring/Summer 1979 catalogue:


As old as me, and considerably more useful...
 
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