Best workshop lighting?

Fluorescent strip lighting. Double tube fittings.

And the same directly over the workbench. To gild the lily, use specialist continuous light spectrum daylight tubes.

For my sitty-down electronics bench which is only about 4 ft wide and in front of a window I have 4 50 watt LV spots as overheads and an anglepoise with a mains halogen 100 watt bulb.

Reply to
Dave Plowman (News)
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Tri-phosphor tubes will reduce this effect as they have longer persistence. But best way is high frequency ballasts - which are more efficient as well.

Reply to
Dave Plowman (News)

I find these hopeless. A cheap pair of +5 ready read glasses and a 100 watt mains halogen in an anglepoise much better.

Reply to
Dave Plowman (News)

To avoid causing audio interference etc the lowest I've seen is about 30 kHz as opposed to the 100Hz flicker of standard fittings. So the strobe speed is 6000 times greater. Just what woodworking machines run at 180,000 rpm?

Reply to
Dave Plowman (News)

Why 180,000 rpm.

A saw blade with 180 teeth would only need to run at about (or some multiple of) 1000rpm.

My table saw would appear stationary with a 1:1 flicker of about 4.4kHz with its 44 tooth blade.

Reply to
dennis

It's also very hot and has a short lifetime.

Reply to
Andy Hall

I've tried this experiment.

I have continuously variable speed controls on my table saw, spindle moulder and planer and have tried numerous types of blades and tooling on each of them.

I have not found it possible, when using electronic ballast fluorescent fittings, to create a strobe effect at all on any of this set up.

Reply to
Andy Hall

I have never been able to see any strobe effect in my workshop and that only has old style ballasts... There are also usually plenty of other clues the machine is running I find anyway - the fact you are cutting wood with it etc is a fairly good predictor.

Reply to
John Rumm

In a workshop with one person it would generally be fairly obvious since normally only one machine is working at a time. Having said that, some dust extractors can have a fair noise level, although typically not the same as the machinery.

However, my spindle moulder runs quite quietly until it is cutting and with the extractor running and with me wearing an ear defender is not that noticable.

In a shop with more than one machine running, the sound of one machine could easily be masked by another

While I think of it, there is another risk that I think should be considered. That is what happens if the power fails when machines are running and the user is plunged into darkness. Some shops have windows but even these won't help if late afternoon working in the winter.

I have modern machines that will stop within the regulatory 10 seconds, some in about 3, but even so, some could cause quite a mischief in a few seconds if the user is surprised. Even with guards and safe working practices of using push sticks and pads and power feeders there is some risk. Some people may have older machines which do not meet the requirements of the Machinery Directive. In workplace environments, most of these should have either been modified or taken out of use, but they certainly appear on the second hand market.

My first attempt to deal with the emergency light issue was to fit some 8W maintained emergency fittings at a few places. These are quite inexpensive and certainly help, but even so, I felt that the sudden drop in light level and the eyes having to adjust was still too much. I therefore invested in one dual 70W maintained fluorescent fitting which is located over my main machines. This will maintain the light level pretty well and such that the drop is not enough to cause the same problem. These are quite expensive at about £110 (even with trade discount), but in comparison with lost fingers there is no contest.

On a related note, ear defenders are an excellent safety item. Not only do they address the issue with machine noise, but they are a great defence when negotiating with SWMBO about all the jobs that you haven't had tuits to do. A 30dB reduction in nagging is well worthwhile. Then in the final analysis, they are very effective against the inevitable cuff round the ear. Of course they should then be packaged with that other very useful piece of safety equipment, the cricket box.

Reply to
Andy Hall

The message from "dennis@home" contains these words:

It'd appear stationary at 44Hz, too. Or, for that matter it'd look OK at 22Hz.

Reply to
Guy King

Generally mains power loss means all the machines will spin down, and instinct says remain very still. There is the (slim) possibility of loosing all the lighting but not machine power, whilst feeding a job that may kick back. But it's a pretty long shot. The HSE accident reports for joinery shops I've read show table saws featuring in 50% of accidents - 90% flouting safety, 10% caught by an unlikely and unlucky chain of events - none due to loosing lights but not power to machinery.

I guess there may be the odd nut out there who's machine doesn't have an NVR. Interestingly my 1800W router has a toggle power switch but does not have an NVR, a tool that could certainly do with one built in.

Reply to
dom

As long as you devote your attention to the machine while its running, all is well. Thats very much the first and main line of defence, and is especially important if working alone.

When people dont pay attention its another matter. And the reality of human nature is we all fail to pay sufficient attention at some point. So the next aim is that _all_ the senses should observe the machine running, not just some. So there is some value in visual cues, even when the sound is obvious. These cues are all normally present with rotating machinery and 50Hz magnetic ballasts.

Awareness of the problem comes primarily from the film industry, but the nature of 50Hz lighting is somewhat different to that of 24Hz film. Film uses a very short exposure time, whereas a mains half cycle gives a much longer exposure time. The result is that when in sync, a filmed cartwheel appears clear and stationary, whereas a rotating machine appears very blurred, only showing at best a limited amount of still visual misinformation. The fact that sync doesnt usually occur, plus the heavy blur when it does makes 50Hz lighting a very small threat.

One solution to it is to put a capacitor in series with the choke on every other fitting. The other is to paint angled stripes on the chuck so the chuck appears to be moving at 90 deg to its real movement. With a xenon strobe this would not be effective, but with the long on-times of 100Hz flicker it is.

near horizontal reflectors outside the windows would increase daylight lighting hours, fwliw.

The battery mode power output of these is usually way down on mains rated power. The plus is the light comes from the same place as it did, so no sudden change in shdows that take the brain half a second to reinterpret

NT

Reply to
meow2222

They've much improved recently. Last one I bought said 2000 hours.

Reply to
Dave Plowman (News)

Except that 50Hz lighting generates in general an unacceptable level of flicker to some people especially in peripheral vision.

This would assume machinery operating at a fixed speed.

This is why it's worth investing in decent ones where this effect is not much.

A lot can happen in half a second

Reply to
Andy Hall

Mains power loss does result in machines spinning down. However, a spindle moulder with a large piece of steel tooling and with no form of braking will take a lot of time to spin down. It does not take much to chop off fingers.

Braking on some machines may not operate if the power fails and they may naturally spin down.

I am sure that the statistics are interesting, although I take a Disraeli view of statistics. There is more than enough energy in a machine spinning down unbraked to do damage.

If for the sake of spending £100 or so on some lighting I can mitigate the risk of losing some fingers, however small the risk might be, then I think that it's a worthwhile investment.

Routers sold today are supposed to have a switch that has to be held on for the tool to operate, so an NVR switch becomes irrelevant.

Reply to
Andy Hall

You are referring to lead-lag pairs. However, it doesn't work like that. The capacitor is the primary ballast component in order to create the leading phase angle. The choke is there mainly to limit the crest factor (peak current) in the tube as it starts conducting each half cyle, which would otherwise result in rather short tube life on a capacitor-only ballast. The choke in a leading (capacitor) ballasted light is not the same component as a choke in a choke ballasted light -- it's much smaller.

Lead-lag pairs were an invention of Thorn Lighting many years ago.

Reply to
Andrew Gabriel

and a right PITA they are as well! Give me a locking switch every time.

Reply to
John Rumm

Interesting point that... I am very sensitive to screen flicker. Even on a screen a small as a 17" CRT, I still find 75Hz a bit on the low side and 60Hz painfully unusable. From about 82Hz onwards I see a static image. However I have not noticed the same problem with any of my strip lights (which I don't think are electronic ballast (if the flickering at startup is anything to go by)). Perhaps they just have a long persistance phosphor.

Yup, I have a 8W one over the CU in my workshop - should help finding the RCD etc, but as you say it is pretty low level as a main light replacement...

Reply to
John Rumm

Fluorescent lighting is normally 100Hz flicker. You can get 50Hz from a tube end, and in the case of a tube which is conducting better one way than the other way -- this often happens just before a tube dies, but can happen in the case of a badly manufactured tube throughout the lamp's life.

Somewhere around 75Hz is the highest limit the human brain can process (for some people it's lower), above which flicker is not observable. Animals with smaller brains can see higher frequencies. Your eyes relay data at over 100Hz, but the brain can't process it. Possibly it would have been able to do so in the evolutionary past when we had smaller brains. Insects can see flicker into the kHz.

Reply to
Andrew Gabriel

really not true.

not at all

yes, especially when taken by surprise and suddenly deprived of all visual clues, which are key to maintaining balance.

NT

Reply to
meow2222

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