MEW 162 – Phoenix Battery Drills

[Peter G. ShawParticipant @peterg-shaw75338]

On further reflection about my plug/socket reversal idea, it would, I assume, be possible for someone to use an extension lead to connect a battery box direct to the mains.

 

I’ve got to say this, because if I don’t someone else will, I have no doubt, point it out to me, but we are surely getting into the realms of fantasy now.

 

Regards,

 

Peter G. Shaw

[john fletcher 1Participant @johnfletcher1]

I have made a power supply and run 2 of my 18 volt drills from it, the PSU also dubs as variable volt power supply using a 5 amp  voltage regulator chip.I remove the duff battery, drill a hole in the side of the battery box, put a substancial piece of flex through the hole, solder the flex to the original battery connection and partially fill the box with sand and cement to ensure it stands upright. Regarding over voltage, I have never as yet  had a motor or its electronics fail due to over voltage.Folk get to involved with imagining problems which just might exist. I have other drils which work well after giving the cells some extremely rough treatment. The problem appears to be that owners never fully discharge the Ni-cads, but keep topping them up.I have Ni-cads more than 15years old and still keep working well, not as they did when new but useful never the less.

[Peter G. ShawParticipant @peterg-shaw75338]

John,

 

Way back in the ’70’s there was an article in Wireless World about Nicads and their failure mode. The author did indeed reckon that the best way to treat Ni-Cads was to treat them rough, ie make them work, and to ensure that they were fully discharged before recharging. The same author also gave a method of reviving “dead” cells. Basically, it involved reverse blasting them with a heavy current to melt the internal short-circuit that caused the failure. His idea was there was nothing to lose as these cells were destined for the scrap heap anyway.

 

The major problem though, is that you need access to each cell to ensure that it is fully discharged and not reverse charged as can happen in a multi-cell battery. I do recall though, seeing somewhere a suggestion that a diode across each cell would stop that problem. The same access problem also occurs when attempting to revive “dead” cells.

 

The so-called memory effect, ie low capacity, is cured by a full discharge and recharge cycle on each individual cell. Again, access problems prevent this from being easily done.

Regards,

 

Peter G. Shaw

[Steve GarnettParticipant @stevegarnett62550]

Incidently, whilst I haven’t looked at the idea in any great detail, just suppose, the mains plugs and sockets used for the drill were wired the opposite way round to normal, ie the socket wired to the drill. This would mean that it was impossible to connect such a drill directly to the mains, would it not?

Peter G. Shaw

 

 

… and it would leave the pins connected to the battery exposed to landing on anything metal. If you haven’t tried shorting out a 12v battery with low internal resistance, you should give it a go! (although by the sounds of it you already have…)

 

Years ago I watched somebody trying to decide which car battery he needed for his car, and he announced that he was going to measure the sizes of them with a tape measure. Before anybody could stop him, he tried it on the first one (this was in a car accessory shop), straight across the terminals. About a foot of tape measure vaporised, he shot backwards and collided with the long stand of bits behind, sending the whole lot crashing to the ground. Complete chaos. Funniest thing I saw all week!

 

KWIL’s right. It’s not intelligence-based – stuff just happens. I don’t care if people blow themselves and electric drills to smithereens, but somebody else might. So warnings should be there for their sakes – not mine, yours or perhaps anybody else’s at all on this forum – it’s just a timely reminder that’s required, in an appropriate place.

 

The other thing to note is that putting a warning on tool instruction also provides a degree of protection against negligence claims – certainly in America. Ask Ryobi – they must reckon that it’s well worth it, certainly in Maryland. It got them out of a deal of trouble over machine guards. Since MEW is distributed in the US, not providing some sort of warning in an article that changes the use of an existing tool… well I don’t know what the actual situation would be over that, but I sure as hell wouldn’t want to be on the receiving end of a no-win no-fee lawyer trying to find out, that’s for sure.

Edited By Steve Garnett on 18/03/2010 19:27:34

[Peter G. ShawParticipant @peterg-shaw75338]

 

… and it would leave the pins connected to the battery exposed to landing on anything metal. If you haven’t tried shorting out a 12v battery with low internal resistance, you should give it a go! (although by the sounds of it you already have…)

 

Of course I have. Hasn’t everyone? Especially at ‘tech’ during Principles classes when learning about valves with 2V heaters!

 

But seriously though, any shorting I’ve done has always been accidental and resulted in, at worst, a blown fuse. I have never seen the results of any such serious shorting out, although I’ve heard plenty of anecdotes about it. Perhaps my training in telecomms was good enough to avoid such mishaps.

 

As regards the car, this was a towbar that was already fitted and wired when I bought the car. It turned out that the power wiring for the connectors was routed under the car in and out of various points between the sockets on the towbar, and the fuse & relay at the front of the engine compartment. What happened was that after a few years, vibration, possible cable movement by mechanics, something like that anyway, and the cable ended up rubbing against a sharp edge. Eventually the sheath and insulation gave way and pop went the fuse. Connect up the caravan, and the caravan battery ends up being connected back down the car wiring to the sharp edge, hence to earth, and pop went the caravan fuse. Which caused no end of head scratching until I realised what had happened. To find the fault, I ended up wiring a piezo-electric sounder across the blown car fuse and moved the wiring about until the sounder operated. No problems after a good repair.

 

Giving a friendly warning of possible problems is one thing. Going overboard and complaining that something experimental is dangerous and should not even be shown is quite another. Especially when said article gives a recommended alternative.  This is a hobby, and we have to allow people in the hobby to think for themselves.

 

Regards,

 

Peter G. Shaw

[Steve GarnettParticipant @stevegarnett62550]

Posted by Peter G. Shaw on 18/03/2010 19:16:10:

 

Giving a friendly warning of possible problems is one thing. Going overboard and complaining that something experimental is dangerous and should not even be shown is quite another. Especially when said article gives a recommended alternative. 

 

Did anybody say that it shouldn’t be shown? I certainly didn’t. The problem as I perceived it was that the recommended alternative wasn’t really quite ‘recommended’ enough, and that was all.

 

I’m all in favour of experiments – do ’em all the time. I’m also in favour of people continuing to be able to do them though, and if a timely warning or two helps that by alerting people to the possibilities, then what’s the problem? I’m not suggesting for one moment that the Ed goes overboard about this – only something sensible, which I’m sure is what he’ll do.

 

Lively debate though!

 

 

[Sub MandrelParticipant @submandrel]

I’ve electrocuted myself enough times to be able to speak with authority on this.

 

We can all make mistakes – I have IEC connectors on several things in my workshop and around the house. But oh no, I’m not stupid enough to get the leads muddled up am I?

 

And its amazing how many people know machinery inside out but really don’t get electricity. There really are reasons why plugs are polarised etc. prat ideas like wiring two 13A plugs to a welder are just so dangerous as to be beyond the pale. The screwdriver idea isn’t that bad, but even the builder changed tack and went to a safer solution so he knows it wasn’t the best way – just a stop gap.

 

Something like this it costs nothing and it is zero effort to make a short comment on safety. I remember someone in one of the mags suggesting wiring capacitors to the mains o make a bridge to test their value – he had unshielded mains floating around, and got shirty when I worte in to point out you could do the same thing in perfect safety by using 12V ac instead of mains.

 

Now I like big bangs as much as the next man, but not when they are someone else’s fault. Even if we don’t have kids, one day we all die and our wife/daughter/son/mate will come to sort through our stuff, and maybe switch on and try it out. I make a lot of electrical stuff, much using mains in it, and while  I don’t hit CE standards, I don’t make anthing I would worry about a kid plugging in and switching on. they might break it, but it won’t break them.

 

 

Cheers

 

 

Neil

 

 

P.S. Some may know SIDE…

 

[Steve GarnettParticipant @stevegarnett62550]

Posted by The Artful Bodger on 18/03/2010 21:12:18:

 

P.S. Some may know SIDE…

 

 

Yeah, the slightly more cautious of us that did power courses back in the day, and worked on a few rather dangerous things – and who seem to be erring on the side of caution in this thread.

 

For everybody else, it’s the mnemonic that’s drilled into you when you are working on anything electrical that could severely damage you or anybody around you – more stuff than you might think, and especially anything with capacitors in it that are likely to retain a charge.

 

Switch off – Isolate – Dump – Earth

 

I’m still here because of that.

 

 

[John ShepherdParticipant @johnshepherd38883]

All

 

A lively debate and the last couple of posts put things in perspective.No one wants to stifle experiment and if no one took risks then nothing would get done but a risk is something you do when you know the danger of what you are doing and have control and more importantly it should not put others in danger.  

I say this from a stand point of having pushed the boundaries many times, not as a H&S control freak.  The facts are:

1. The use of IEC connectors in this application is dangerous.
2.. A 3rd party could inadvertently but not unreasonably connect 240v mains – the same could happen      during a senior moment with other IEC leads on the bench for example.
3. It could kill or cause serious injury.
4.. It is bad practice.
5.There are better ways of doing it that are no more difficult to achieve or are more expensive..
6.There was no reason to show the use of these connectors in the article unless to illustrate and fully explain good and bad practice. 

 

I trust the author and editor will not be discouraged by these and other comments.  For my part at least, they are intended to be constructive and in no way a personal attack. 

My hope is that some day I will pass the contents of my workshop onto my grandson – I do not intend to pass on anything that is not reasonably well engineered or is unsafe when used properly. 

John Shepherd

 

 

 

Edited By John Shepherd 1 on 19/03/2010 09:01:39

Edited By John Shepherd 1 on 19/03/2010 09:03:15

[CirclipParticipant @circlip]

And just to re titilate on this one, how many CIRCUIT DIAGRAMS  have been printed incorrectly in the past, reversed positive and negative notations for instance???? The same Graphics persons that got mechanical dimensions incorrect have also managed this one.

 

  Given the six combinations that SOME can achieve when wiring a 13A plug, it is not very reassuring and makes one realise why you now need a skilled sparky to fit a fuse.

 

  Regards  Ian

Edited By Circlip on 19/03/2010 12:47:17

[Nicholas FarrParticipant @nicholasfarr14254]

 

Like most people I was horrified to see mains plugs/sockets being used on battery drills and imagining the danger if it was inadvertently plugged into the mains. I like many others I have experimented using things that were not specifically designed for the use that I have put them to. In your article I believe that photo 1 would suffice to show the first trial of this experiment along with a little text explanation. However pictures are remembered better than words and some people don’t even read the words. (Most self assembly instructions are in pictures with very few words these days) To see several close up pictures of mains plugs being fitted and wired I believe is a bad idea, as some people will see the photo and think that’s a good idea and believe they have enough info to complete their own interpretation without even thinking of the potential hazards. You can argue all you like about the do’s and don’ts and so called idiots in the workshop, but however clever or intelligent you are we all make stupid mistakes, ever picked up a piece of metal shortly after you’ve just welded it, ever chopped the end off your tape measure in the guillotine, ever made a pot of tea and forgot to put the teabag in, ect, ect, we all need a little idiot proofing now and again. As it has already been mentioned, it is those who follow us, e.g. children who may not be familiar with what we modify that may be heading for a disaster. In these days of no win no fee, idiot proof safety or otherwise is something we should consider. Nick.

 

[Donhe7Participant @donhe7]

After reading this thread, I remember the practice of (many tears ago) using the standard Australian 3-pin 240 volt plugs and sockets for trailer wiring, I think because of the expense and difficulty of obtaining the proper trailer units.

  Since those days things have changed considerably, and various types of low voltage connectors have become available, and to my mind it is inexcusable to even consider using ANY 240v (or 230v), connector for low voltage supplies, as anyone who is/was unaware of the situation, could attempt to plug said IEC plug into the low voltage side of the supply, if the pins are on that side of the assembly, with disastrous results, conversely as was originally, stated, a similar result would/could occur.  I don’t know what the situation is “over there”, but here in australia, we are able to purchase low voltage plugs and sockets at various Auto Accessory stores, so a much safer alternative should be able to be obtained if the time and trouble was taken to look for it.

 Not that I, myself, am greatly in favour of the “Nanny State” in which we are being increasingly forced to live, I would rather see some risky practices ended.

 

Donhe7

 

 

  

Edited By Donhe7 on 20/03/2010 14:15:50

Edited By Donhe7 on 20/03/2010 14:18:24

[Gordon WParticipant @gordonw]

I’ve just been reading the latest MEW, I have noticed several adverts for expensive machinery, beginners should be warned that these ads. can severely affect your marriage. Then I read an article advocating that I stare out the window with my eyes crossed ! do not do this with people around! There is an article about battery drills, I’ll read this when my eyes get back to normal.

[Steve GarnettParticipant @stevegarnett62550]

Posted by Gordon W on 20/03/2010 16:32:24:

 

Then I read an article advocating that I stare out the window with my eyes crossed ! do not do this with people around! There is an article about battery drills, I’ll read this when my eyes get back to normal.

 

I think that people have put what amounts to warnings about the expensive machinery syndrome re. continuing viability of marriage before, but yes you are correct – another idiotic mistake can easily be made there. I’ll leave individuals to work out whether it’s the marriage or the machinery…. *

 

I can’t make that supposedly stereoscopic thing work for me, even though I can manage those ‘magic picture’ books without difficulty. Anyway, after you’ve read the electric drill thing, your eyes may well be crossed again, and your mouth gaping wide open as well…

 

 * (OT) SWMBO doesn’t really care about the machinery as long as it’s relatively cheap, doesn’t get in her way and I get all the stuff she wants done along the way. What she’s most concerned about presently is where the rest of it’s going to fit in the W/S (quite a bit is in storage awaiting restoration). Has she got a point? Is my plan going to work? Ask me in several months time… but yes, it was all very cheap, otherwise I wouldn’t have had it. I’ve never had much of a problem with resisting ads for very expensive new machinery – it’s the private ads for cheap S/H bargains that I’m a sucker for!

 

[Sub MandrelParticipant @submandrel]

the pics were hard work. I think the perspective is too severe for me, I could only get part of all but one picture to work. I wonder if reducing the angle or making the vanaishinjg point much further away would help?

 

Yes we can all do stupid things. I left my Antex soldering iron left switched on all last night. i still have aworkshop, but the element blew and farnell no longer stock CS elements. They are twice the price from other places

 

Neil

[CirclipParticipant @circlip]

Whichever plugs and sockets one uses, they won’t have been designed for connecting a battery operated drill to a dedicated power supply.

 

  Yes Nicholas, that’s why I’ve been castigated many times for playing c**p about the more “learned” showing photos on forums of dangerous practices and excusing it by saying “I’ve been a machinist for XXX years”

 

   If brains were — some couldn’t even blow their hats off.

 

  Regards  Ian.

[John Stevenson 1Participant @johnstevenson1]

What about publishing articles in the magazine that have an element of risk attached  by using white text on white paper ?

  

That should please all the flat earth society.

 

.John S.

Edited By John Stevenson on 22/03/2010 13:17:15

Edited By David Clark 1 on 23/03/2010 12:06:31

[David Clark 13Participant @davidclark13]

Hi John

I could do but then they would complain that they could not buy white ink to print it out.

regards David

 

[CirclipParticipant @circlip]

No, but you could get black ink to print on black paper and then the grubby finger marks wouldn’t show.

 

  Regards  Ian.

[Jeff DaymanParticipant @jeffdayman43397]

in my opinion low voltage devices should never be fitted with mains plugs or receptacles, to prevent the risk of them getting plugged into mains. If it can be it will be.

 

There are so many low voltage connectors around, and some really cheap ones for cars, I would encourage people to use those instead.

 

The “weatherpack” style are reliable even in wet weather, and have no exposed male metal terminals. They are recessed in the plastic shells to resist shorting when disconnected. Spade connectors are also available now with nylon shells around male and female terminations, are very cheap and can be crimped without special tools. Panduit and Faston are two brands.

 

I believe a statement should be made that the mains plug arrangement in the article was for experiment only and that low volt connectors are recommended for anyone making drill mods as described.

[Ian S CParticipant @iansc]

A good connector is the one that fits car ciggy lighter sockets, you will then be able to use the drill from the car. I use this system on a home made petrol powered power supply (Villiers 2 stroke an lucus car alternator). Ian S C

[John ShepherdParticipant @johnshepherd38883]

What about publishing articles in the magazine that have an element of risk attached  by using white text on white paper ?

 

 

That should please all the flat earth society.

 

.John S

 

I find this post offensive and this type of comment, particularly the Italian reference, has no place in this type of forum. The fact that it appears to be supported by the moderator and editor in the following post does not help in my opinion.

I think it should be removed.

 

John Shepherd

Edited By David Clark 1 on 23/03/2010 12:05:34

[CirclipParticipant @circlip]

Most of todays battery powered DIY toys have Nimh cells fitted which was/is supposed to eliminate the “Whisker” theory so it’s pointless Zapping them.

 

  Yes, I agree, the frivolous comments should not be taken any notice of, Percival will be rotating at a dangerous speed that some may regard a serious forum to be used for sutch waggery. 

 

  Regards Ian

[David Clark 13Participant @davidclark13]

Hi There

I did not support it, missed that bit.

Only replied to the white ink bit.

Now edited out.

regards David

 

[Steve GarnettParticipant @stevegarnett62550]

This whole ‘element of risk’  thing is ridiculous. Everything has an element of risk about it – even posting this comment, for heaven’s sake, as you’ll see. At the extreme risk of stating the blindingly obvious, the only elements of risk that needs to be considered seriously in this context are the ones that could significantly affect 3rd party users rather than the perpetrators, whom we have generally agreed can look after themselves – and we have to assume the worst case here, which is that this is to the exclusion of any or all others.

 

I think that the general point has been made, quite sufficiently. David, could we lock the thread now before it gets any sillier?

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