Earthmoving equipment, buses and trucks have been using these for years – but in the past they’ve been too expensive to consider for us. So what is it then? It’s an hour meter – it simply records how many hours the vehicle has been running.
If you drive a vehicle that spends a lot of time idling, it’s likely that an hour meter will give you a better guide to oil change intervals than the odometer. For example, 100 hours at 80 km/h average equates to 8,000km, but at 20 km/h average that’s only 2,000km! To put this another way, if you’re not moving forward but the engine is running, it’s still degrading its oil…
And the good news is that the pictured hour meter is available on eBay for just AUD$7, including postage to your letterbox. That makes it cheap enough to fit just for interest’s sake.
It works on voltages from 10 – 80V and you simply wire it to an ignition-on supply. Internally it doesn’t use a DC motor (because that would vary in speed with supply voltage) but instead an escapement mechanism like a clock. Apply power and it starts ticking…
Quick wiring adaptor
One of the problems with quickly and easily wiring a device (like the above hour meter) into a car is tapping into a power feed. You can try to access the back of the fuse box, or tap into the cigarette lighter wiring, but especially in current cars, getting access to this wiring can take forever!
But now there’s an easy way that will take only moments.
Shown here is an adaptor that plugs straight into a spot in the fuse panel. You simply pull out an existing fuse, plug in the adaptor and then plug the original fuse into the adaptor. Hey presto – one power supply feed that is even protected by its own fuse.
The adaptors are available in both standard blade and miniature blade sizes, and come with four fuses of varying values.
Search on eBay under “Medium ATM Fuse TAP Add on Dual Circuit Adapter Auto CAR Holder+7A 10A 15A 20A” and pay just AUD$5, including delivery to your letter box.
Tyres are one area of a performance car where costs can go sky-high. So it makes sense that more and more people are scouring the web, looking for on-sale tyre prices that are way under retail.
And without a doubt there are bargains around.
But what a lot of people don’t realise is that they might well be buying old tyres – ones that have been sitting in a warehouse for years. So what is wrong with that? In short, if a tyre is not stored correctly, the rubber will start to degrade. It will harden, and may even crack – either in the ‘valleys’ of the tread or in the sidewalls.
So if you are buying bargain tyres sight unseen, ensure you ask how old the tyres are. Up to 3 years should be fine (although if they’ve been stored under the tin roof of a hot Australian shed, maybe not), but anything over that and you start buying with extreme care.
And how do you ascertain the age of tyres, anyway? It’s actually very easy – tyres are marked with a build week and year.
Just closely inspect the outer wall of the tyre until you find a mark that appears to be stamped rather than moulded. This one says F3A0710. It’s the last four digits that are relevant – the tyres were made in the 7th week, 2010.
Grinding without the rest or guard
These days, 6-inch and 8-inch grinders are very cheap. They’re also a very useful tool in any home workshop – for duties as diverse as sharpening drills to shaping sheet metal.
That said, a grinder is also a dangerous tool. You should always wear hearing and eye protection when using one. You’ll also find all the textbooks suggest that the flip-down glass or plastic shield fitted to most grinders should always be in place, and that you should never use a grinder without the ‘rest’ – the metal support on which the work-piece rests while being ground. But I don’t know about these two.
Firstly, the plastic or glass shield invariably gets filthy – and if you can’t clearly see what you are doing, safety suffers. Better in my opinion to leave it off and use safety glasses.
Secondly, I have been using one wheel of my 8-inch grinder without the ‘rest’ for the last 12 months – and I think it is easier to use and for an experienced user, no less safe. One argument for using the rest, and having it positioned close to the wheel, is that the work-piece cannot be snatched downwards and get jammed between the guard and the wheel. And of course that’s true. But most work-pieces won’t get snatched, and having the freedom of movement that the lack of a rest creates means you can manipulate the work-piece much more widely and effectively.
If you are experienced in using a grinder and normally have no problems, you might like to try these approaches. (And if you are not experienced, do everything ‘by the book’ at first!)
Adjustable battery charger
If you have the need for a battery charger and would like to keep it cheap, here’s a good approach. Available now on eBay are variable constant current and constant voltage modules. By twiddling some on-board pots, you can set the maximum current to be anything from 0 – 3 amps, and the voltage from 0 to whatever is the maximum supply voltage of your power supply.
So what power supply then? A zero cost option is to use the power supply from an old laptop – these are often around 20V and 3 amps.
So you buy the module on eBay (from around AUD$4 including postage), power it from the ex-laptop power adaptor … and then what?
Well, let’s say you want a 2 amp battery charger for your car. Using your multimeter to monitor the voltage output of the module, set the constant output voltage pot so the output is say 14.4V. Then set your multimeter to measure high current, and connect the multimeter straight across the output leads. Set the current pot so that the meter reads 2 amps.
The module can then be connected straight to the battery, and will charge it up nicely.
(We wouldn’t go over a continuous 2 amps with the module we tested - it ran a bit hot at higher currents.)
Or say you want a trickle charger that can be left connected permanently to the battery. In this case, set the current pot much lower – say to 200 milliamps. You can set the voltage to say 13.8V, and then the battery will be maintained at a fully charged level.
If you have an old laptop power adaptor around the place, and don’t mind setting-up the module and placing it in a box, it’s an incredibly cheap and easy way to achieve the outcome.
To find these modules, look up ‘constant current constant voltage’ in the Electronics section of eBay.
Anyone working in a workshop fabricating larger items frequently uses a bubble level – primarily for checking level horizontally but also for checking verticality. But if you want a flat surface truly horizontal, checking that requires using the level twice – once with the level pointing north/south, and the other time with the level pointing east-west.
And that’s where this tiny T-level comes in.
Sold primarily for use with caravans, the level uses two bubbles arranged at 90 degrees to one another. By using the level, the “horizontalness” of a plane surface can be assessed at a glance.
Its uses are not confined to fabrication. If you have a tilt-table drill press, you can quickly see if the table is level or has been set slightly rotated, and whether the table is at 90 degrees to the column. (Of course, start off by levelling the bench on which the drill press is bolted!)
At around AUD$5 including postage, it’s definitely worth buying one for the workshop.
I know the current fashion is for rechargeable battery power tools – but for a home workshop, such an approach isn’t always the best.
Of course rechargeables have clear advantages over mains-powered tools in some areas – they are lighter, safer and often have better speed control. But for my home use at least, those aspects are often outweighed by the fact that they’re designed to be in use a lot of the time – batteries charged, discharged, charged… and so on.
In my home workshop, some power tools might not be used for a month at a time – and rechargeable tools hate that type of use. In fact, I’ve given up counting how many battery tools I have killed, primarily through too intermittent a use.
And in addition to not having batteries that die, mains-powered tools have other advantages – they’re cheap and powerful. In fact, bought second-hand, they’re nearly free…
So by all means use rechargeable tools in the areas where the tool is often in use, but for other tools, consider the advantages of plain old mains-powered tools.