MEW 162 – Phoenix Battery Drills

[Steve GarnettParticipant @stevegarnett62550]

I don’t have any problems with the concept of converting battery drills to being ‘corded’ ones – I’ve been doing it for years, for exactly the reasons given in the article.

 

What does worry me quite a lot though is that Martin appears to have used IEC 16A sockets on the drills. As a result of this, I’m starting a book – who’s going to be the first to admit to having the mains plugged straight into a 12v DC Drill, probably by a completely unsuspecting third party? 

 

The other things I’m wondering are; how big the almost inevitable bang will be, and whether anybody’s insurance will cover the potential consequences?

 

On the drills I’ve done, I left the cord permanently attached to the drill, and had a connector on the other end only. Is there a more sensible connector to use? Of course there is. For years, there’s been an XLR standard for using 4-pin connectors for battery power, and CPC sell them, so there’s no problem there. Each pin is rated at 10A, and if you double up the positive and negative wires so that each uses two pins in the connector, then you’ve got a greater current rating than the IEC connector has anyway – and also, it latches so it won’t keep falling out, as the IEC ones are prone to do in anything mobile – which is why, even with mains appliances, they aren’t recommended for this type of application.

 

No, it’s not just me – this really is a bit crazy.

 

[Steve GarnettParticipant @stevegarnett62550]

Is this dangerous or what?

[David Clark 13Participant @davidclark13]

Hi There

The original drills used mains connectors.

The article conversion is done with low voltage ones.

regards David

 

[John ShepherdParticipant @johnshepherd38883]

I sent this email to David Clark as soon as I read the article – In the interests of safety I’m sure he wont mind me repeating it here.

 

I read with interest the ‘Phoenix Battery Drills’ article by Martin Gearing. I would certainly not subject him to a flogging for connecting a 9v Drill to a 12v battery as he fears some would but I might (metaphorically) suggest it for showing his use of IEC mains connectors. I accept that Martin has moved on to Speakon plugs and I have no problem with those but there is a real danger that someone could plug a mains lead into a battery powered drill modified with  a IEC socket.  This has the potential to cause serious or even fatal injury. I urge you to warn your readers not to follow this example at the earliest opportunity.

 

John Shepherd

[Steve GarnettParticipant @stevegarnett62550]

Despite what David implies, the article doesn’t suggest using Speakons for anything other than the battery box – I’ve just read it again and it’s pretty specific about this: In the first paragraph on P44 it says “The other end of the lead has to have a Speakon plug fitted”, directly implying that this isn’t the case at the drill end, even though the later pictures show perhaps something different. Say what you like, but this really isn’t made clear in the text. In fact, it’s not even mentioned anywhere that I can find. So if both John and I have clearly been given this impression from the article, I’d say that there’s a pretty good chance that others will be too.

 

 

Edited By Steve Garnett on 17/03/2010 21:01:15

[David Clark 13Participant @davidclark13]

Hi There

When I first saw the article I thought the same as you, mains socket – no.

Then I read the rest and looked at the photos and list of components and it clearly says on photo 4 caption Strain relief bushes in place with cables installed.

Photos 9 and 10 clearly show strain relief cables and Speakon plugs and sockets.

 

The text in column 1 on page 44 says A filler piece to allow the installation to the handle of a cable bush, preferably with strain releif.

 

I don’t see a problem with the article.

regards David

 

 

Edited By David Clark 1 on 17/03/2010 21:16:06

[Steve GarnettParticipant @stevegarnett62550]

Sorry, I still think that I’d have liked to have seen a specific statement about this, and that certainly isn’t there; nowhere does it specifically say that using IEC sockets is a distinctly bad idea, and I think it should. I know it’s your call, but even so…

[Brian StillParticipant @brianstill44962]

Hi

 

I think that the problem with the article is that it shows photos of an early version that is definitely poor design.  I have no problem with using the drills with an external battery if it is carried out to the later design.  It’s a pity that three photos show the earlier version.

 

It is difficult to prevent this kind of thing happening as we perceive dangers differently to each other.

 

David, I am impressed with the way both magazines are now being produced so please carry on with the good work despite criticism.

 

Regards

 

Brian

[David Clark 13Participant @davidclark13]

Hi There

I will put something in the magazine next issue but how far do I dumb down the content?

We are talking all sorts of dangers in every issue. Do I treat everyone like an idiot until they prove otherwise?

regards David

[Steve GarnettParticipant @stevegarnett62550]

Okay, my take on it:

 

I don’t think it’s about dumbing down at all. You can put all the dangerous stuff you like in the mag, but you are still morally obliged, I feel, to point out dangers, especially ones that aren’t perhaps quite so obvious. And this probably applies most to tooling that could be used outside the workshop, potentially by almost anybody else. So I’d say that really, what needs to be said about any particular situation is simply a matter of risk assessment. If there’s electricity involved, then err on the side of caution, simply because it’s invisible. If something’s visible, then there’s a far greater chance of common sense coming into play anyway, so I’d say that it was less of an issue.

 

I think that intelligent people will appreciate almost any comment about safety for exactly what it is – because they are intelligent. If the idiots have anything about them at all, then they should be grateful that somebody is looking out for them. I’m sorry if that sounds patronising – I can’t immediately think of a better way of putting it.

 

Oh, and I agree utterly with the comments about good work in the mag production. This is meant to be positive criticism, not the negative stuff – I hope that’s clear, because that’s entirely the way it’s meant. 

Edited By Steve Garnett on 17/03/2010 22:46:21

[KWILParticipant @kwil]

Rather than being specific about which connector to use, etc. the ones used could be stated as being an example (hopefully of being good practice), HOWEVER an overiding statement such as ” Electricity can kill, if you do not fully understand what you are doing, consult somebody for advice who does understand, “

[Steve GarnettParticipant @stevegarnett62550]

Okay, I can think of perhaps a slightly better way of putting this into a bit of context. When Martin, who is clearly an intelligent guy, first did this conversion he was clearly concerned with getting a result – by whatever means was to hand. And in the circumstances in which he was operating (presumably surrounded by other intelligent people), what he did, he may not have been considered to be too much of a risk.

 

But nevertheless, he did it. And if he makes even the suggestion that it’s perfectly possible to get it working like this, then other people might consider the same course of action, perhaps without assessing the risks in the same way. That doesn’t make them idiots – it’s just that not all things occur to all intelligent people at the same time. And not all intelligent people are intelligent in the same way, either, and the potential consequences may simply have escaped them. It happens – probably more often than one would like to think…

 

And that’s just the intelligent people. You can work your way down from there.

 

 

 

[DMBParticipant @dmb]

I think that David really ought to put in a warning such as `KWILL` suggests, in front of every copy of MEW if not ME as well, just to cover himself and proprietors. Maybe something like what appears in the front of many re-printed American books on mechanical / electrical subjects.

Well done David, for vastly improving 2 already good mags. – keep it up!!!

John.

[Ian S CParticipant @iansc]

John, the warnings are not only on books but on web sites too, usually worded so a kindergarten kids would understand it.My 9.6V drill ($2 with dead battery)died after 2 years use on my workshop low volt DC line-18V, must get another one,maybe 12/14v.I use the plug and socket from an old transistor radio, and wire permanantly wired into the drill.Ian S C

[CirclipParticipant @circlip]

WARNING! If you stand in front of a bus you are likely to DIE if it hits you. Anyone attempting electrical work without knowing what the’re doing or obeying basic safety rules deserves to be rushed into hospital for another cell to be implanted. Trouble is, it would probably be lonely.

 

  If the HSE entered ANY of our workshops they would put a closure notice on them, we ALL “Risk” it at times as has been proved many times on THIS forum. Sadly the words COMMON SENSE seem to have dissapeared from our vocabulary.

 

  Far better, on the cover of BOTH M/E and MEW, in 120 point, David should insist the words CAVEAT EMPTOR be printed in bright red.

 

   Regards  Ian.

[David Clark 13Participant @davidclark13]

Hi There

No matter what is done, someone will mess it up or cause something to happen.

Reminds me of a youth opportunity lad we had many years ago.

Will put the story in Ed’s Bench in the next issue.

regards David  

[KWILParticipant @kwil]

Reminds me of a youth, [not me I hasten to say],  who, standing by a machine planer (wood), which was making its usual high pitched rotational noise, passed his flattened hand across the blade area, saying “is it working??” Tables were set flat and the guard was in place fortunately. You never can tell, intelligence does not enter into it.

[KWILParticipant @kwil]

 

 

Edited By KWIL on 18/03/2010 11:52:16

[David Clark 13Participant @davidclark13]

Hi There

I remeber once, just before christmas, it was very cold, the labourer was wandering around without a shirt or vest on.

I thought it was strange.

He had been moving a large tumbling barrel from one factory to another.

Reassembled it and switched it on.

He had lost a grub screw from the main shaft and had replaced it with a standard Allen screw.

His overall had caught in the machine,  it was nylon as well. The machine ripped of his overall, shirt and vest.

He spent about a fortnight in hospital over Christmas.

He was about 60 years old and had been working with machinery most of his life.

regards David

 

[Peter G. ShawParticipant @peterg-shaw75338]

Ok, this is my take on it.

 

I think a lot of you are going well over the top on this. It is a suggestion of what could be done. It does not give full constructional details of how to do it, merely ideas. I think we should all accept that in any design there will always be experimental phases leading to improved designs: the fact that he has used mains connectors, and then later used something else is an example of this.

 

Let’s face it, just who is likely to use such a device? Joe Soap down the street who doesn’t know one end of drill bit from another? No, it is going to be people who already  have some mechanical/electrical/everything else skill. And we should, nay must, learn to trust people to know their own limitations and abilities. If we don’t then we are going to end up doing nothing because of fear that someone else may do something daft. That way leads stagnation, and Lord knows, we have enough of that already in this country.

 

Let me put it another way. My five year old grandson saw me inserting plastic plugs in a wall with a hammer. “Can I do that Grandad?”. “Of course you can.” And I gave him the plugs and the hammer. Now should I have done that? After all. he may have dropped the hammer onto his 5 year old toes! Or hit his 5 year old hand whilst holding the plug. That grandson, now getting on for 15 and doing an engineering course at school (and for that matter trusted by his teacher to act responsibly which is more than the teacher can say about other pupils), is now considering, and talking to his dad to see if they have a 14.4v drill for modification! With my blessing, and support!

 

Come on people, lets apply some common sense to all of this. We are not (yet) ruled by ‘Elf ‘n’ Safety’ in which case nothing like this would ever see light of day.

 

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

 

[CirclipParticipant @circlip]

Certainly make it easier to test the line connection

[David Clark 13Participant @davidclark13]

Hi There

Having once seen an extension lead at a model railway exhibition where the plug was live, your suggestion about reversing the plugs would be dangerous.

I bet you never saw that coming?

Whatever you do, you will never get it right in the eyes of some people.

regards David

 

[BaldricParticipant @baldric]

Posted by Peter G. Shaw on 18/03/2010 12:21:48:

 

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?

 

Not a good idea, just changes what can be plugged in, in this case the battery. There is also another amins connector type see here. This is/was used in the broadcast industry, problem was that the BBC used it the other way round to other comapnies, so hired equipment was a bit dodgy, but there again only engineers had to deal with it and no one was killed!

 

My take on this is that for an experiment it is OK, but there ought to be a warning against it for long term use, just use a different connector.

 

Baldric

[GarthParticipant @garth]

 Hello  Peter,

I agree in general with your point of view. I am amazed with all the safety inspectors running around and insurance company’s backed by the legal profession are forever sticking there noses into all areas of our lives bemoaning the safety angle when we really know it is another method of screwing money out of us. It is in a large part in Australia, don’t get me wrong I am not against standards of safety ,but I look back over 50 years of engineering and electrical engineering and wonder how I managed to survive without all these safety experts telling me how to do things.

One point Peter we don’t reverse the plug and socket sequence as this would expose ” live” pins which could easily short out in contact with metalwork.

Regards Garth.

 

[Peter G. ShawParticipant @peterg-shaw75338]

Re: my reversal suggestion.

 

Given that the “plug” would, I assume, be hard connected, ie screwed to the battery box, it would, I suggest be somewhat difficult to connect the battery to the mains! Indeed, I would suggest that only someone with a death wish would be able to do it.

 

As I said, putting the “socket” on the end of a flying lead from the drill would prevent anyone from connecting the drill directly to the mains.

 

Exposure of the “live” pins is a possibility, but this is only from the battery. And before anyone tries to tell me about the energy potential of lead-acid batteries,  may I remind you that my career was in telecommunications which run, or at least used to run, on 50V DC, normally from rectifiers, with a large, indeed very large lead-acid battery backup, and depending on size of exchange using many hundreds of amps as a normal matter.

 

Actually I was aware of that when I wrote what I did, and it was meant a bit tongue in cheek, but may I point out a precedent? My car and caravan are linked together by a plug and socket arrangement. Both car and caravan have a battery in them. Guess what, in both instances live 12v dc can be found across two of the terminals in both the socket and the plug. Admittedly, in both instances protected by a 10A fuse – as I found out when the wiring on the car went short-circuit, and after repair still didn’t charge the caravan battery! So, in respect of my suggestion, which was, as I have said, initially written tongue in cheek, perhaps it’s not so daft after all. Fit a fixed “plug” on the battery box with a 15A fuse between the “plug” and the battery, and a “socket” on the end of a flying lead from the drill: the drill cannot be connected to the mains, and whilst the battery box could, it is extremely unlikely that it would happen. Vanishingly small, I would suggest.

 

Having written the above, I now have a further suggestion to make which will, I think, cover a lot of the points that have been mentioned in this thread. Why not use a caravan plug and socket? The old 7 pin type I admit does have some problems caused by sideways movement, ie “waggling” whilst trying to separate the two. But, with seven pins, one could link three together for the positive, the other three for the negative thus increasing the current capacity, and leave the centre pin (say) unused. But, the sockets come with spring loaded covers thus weather proofing the socket, and the same cover also tends to assist in holding the plug in place. Furthermore, the sockets come designed to be attached to a flat surface and usually have three holes ready for such attachment. In fact, one could go even further (possibly) and wire it up just as a car/caravan would be, hence allowing the drill to be used from the car. Ok, ok, I know there is nowadays often an auxiliary power socket somewhere in the car.

Regards,

 

Peter G. Shaw

[Author]

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