Advice pls on buying power tools

[Lindyboo]

Greetings all. I need to buy power tools, but I’m not sure which to go for as I don’t understand much of the terminology. I’d prefer to have cordless tools, but need to know about the following:

1. What’s the difference between Li-Ion and Ni-MH/Ni-Cd batteries and which is the best?
2. Are tools with a higher voltage more powerful and better than those with a lower voltage?
3. In respect of drills, what does SDS mean?
4. Drill spec’s and Jigsaw spec’s are shown with different depths for drilling wood/metal etc – for example, capacity in wood 130mm (Jigsaw) but in metal 10mm. Why the difference?
5. What are Impact Drivers and Impact Wrenches?
6. What does ‘no load speed’ mean?
7. What’s the difference between a Drill/Driver and a Combi-Drill?
8. Electric saws – I need one that will do for slicing great lumps of wood into logs for the fire. Could a reciprocating saw or an alligator saw be used for this? (I’d prefer not to use a chainsaw).

Forgive my ignorance on all the above, but I’ll be glad of any advice.

Cheers

 

[skier-hughes]

Let's get started
2. Generally yes, but you have to also take into account the make and quality. Bosch say do a green range which is for consumers - normal diy and a blue range which is better quality and aimed more at professionals, so a pro 15v drill could be better than a diy 18v.
3. An sds drill will hammer away without turning, so a drill turns, a hammer drill turns and hammers, an sds drill hammers. Useful for removing cement plaster!!
4. You cut a piece of wood then a piece of metal of the same thickness, which was easiest? The wood. The depths are those that the item can cope with, without failing.
5. Impact tools are used by positioning them and then hitting the head with a hammer, this will then turn the screwdriver end or wrench end. A chisel is an impact tool.
6. No load speed is when you turn on the drill without drilling into anything, once you start drilling or cutting the speed will fall.

 

[MdB]

1. Different types of battery. Don't know which is best.
2. Not always. Not sure about generally.
3. Slotted Driver System (I think). Used mainly for tough jobs (concrete for example)
4. Metal is harder than wood to cut through so the jigsaw can't go through as much in one go.
5. Type you hit with a hammer???
6. The speed it turns when doing no work.
7. Not sure.
8. Chainsaw is the machine for that job (and I got one for Christmas )

My policy with tools is to buy the cheapest I can find first to see how useful they are. Those that show their worth, I replace with a good one. Its a policy thats worked well so far.

 

[biffvernon]

Being a luddite, I do not posess any 'cordles' electric tools. I have a theory that you get more power per pound with mains tools. But I usually work in a shed not a field.

Only but a tool as and when you get to a job you can't do without one.

 

[bower1]

Some other opinions (for what they are worth):

3. SDS is a quick release system, so no chuck key required to change drill bits. I've not found them good for small holes (e.g. for rawlplugs) as too poweful, but VERY useful for making holes for pipes etc. You can get SDS drill bits up to 1m long!
5. Impact drivers (and wrenches) are used for undoing screws or bolts that are stuck. Wouldn't be top of my list for houses (rather than cars) but still useful.
8. I've got an electric chainsaw, it doesn't feel as 'scarey' as a petrol one, and still does a good job. Obviously not much good if you are out in a wood though! Other saws will not saw deeper than their own length.

I find http://www.screwfix.com and http://www.toolstation.com good value for tools.

 

[MdB]

Only but a tool as and when you get to a job you can't do without one.

Getting the right tool for the job is very often worth it. Example, spending £40 on a wall chaser was a very good buy compared with trying to do it with an angle grinder or hammer and chissel.

 

[skier-hughes]

Some other opinions (for what they are worth):

3. SDS is a quick release system, so no chuck key required to change drill bits. I've not found them good for small holes (e.g. for rawlplugs) as too poweful, but VERY useful for making holes for pipes etc. You can get SDS drill bits up to 1m long!
.

You need to buy SDS bits to use in the sds drill, or a special chuck for normal bits to go in.

 

[bower1]

You need to buy SDS bits to use in the sds drill, or a special chuck for normal bits to go in.

Yes, thats the point made clearer. I don't think an SDS drill is an alternative to an standard electric drill (cordless or not), but something in addition.

There are also two sizes of SDS bits (as I've found to my cost). "SDS plus" is the usual one, and mostly OK for home use.

 

[Gervase]

The only things worth getting cordless (in my opinion) are an impact drivers and a small drill. The impact driver is the best thing there is for putting screws in, and will be worth its weight in gold, while the drill is handy for pilot holes.
Otherwise get corded stuff - it's cheaper, more powerful and you don't have to worry about the batteries only lasting 18 months or so.
A reciprocating saw can cope with logs pretty well, and the blades are a quarter the price of alligator saw blades. You can also get good brick-cutting blades for a reciprocating saw.

 

[inwood]

3. If you get a variable speed SDS drill you can 'gently' drill holes as well. I've just used my SDS for drilling 6mm holes in limestone very slowly and it worked much better than my normal drill with a masonry bit. Oh and as someone's already said getting access to 1m long bits is a necessity when your walls are 900mm thick!
5. Impact drivers - only recently found out about these myself when I saw one used. They are the stubby looking cordless drills, little bigger than your hand which only seem to have appeared recently on the mrket.
http://www.diynetwork.com/diy/tl_drills/article/0,,DIY_14385_2277797,00.html
They produce high torque and a light hammer action for driving screws into timber, etc. I've lost count the amount of screws that I've taken the head of off by trying to put pressure on the screwhead through the drill.

An impact driver will drive screws into timber like it was butter.
7. a Combi drill normally has a hammer action for masonry bits.

 

[Flyfisher]

1. What’s the difference between Li-Ion and Ni-MH/Ni-Cd batteries and which is the best?

Li-Ion = Lithium Ion
Ni-MH = Nickel Metal Hydride
Ni-Cd = Nickel Cadmium (often called Nicads)

All this relates to the type of chemistry used within the battery cells. The 'best-ness' of batteries is generally their energy density, i.e. how much power can they provide in the smallest package. In this respect I think the above list is already in 'best' order, i.e. Li-Ion first.

But probably a better measure of 'best-ness' is the rated capacity, which should be stated somewhere in the tool spec. This is measured in Amps per Hour (Ah) or sometimes milliAmps per hour (mAh). Generally, the higher this number, the more power the battery will provide between charges.

Be careful to read the 'battery care' instructions that come with the tool. Abusing the batteries will reduce their life.

Make sure you get two batteries, so one can be charging while you're using the other. Try to standardise on a battery voltage and type so you can share batteries and chargers between all your tools and not make mistakes when charging. Charging a battery with the wrong charger can seriously reduce the life of the battery.

I think the other points were already covered.

An impact driver will drive screws into timber like it was butter.
7. a Combi drill normally has a hammer action for masonry bits.

I've become a big fan of Spax screws for timber, using a normal 14.4volt Combi drill/driver.

Oops - I seem to have clashed with Penners. Good job we said basically the same things :wink:

 

[Penners]

1. Lithium-Ion is the latest type of battery. It claims to have much less "memory-effect" (see explanation below) and tends to be the quickest to charge. Nickel-Metal-Hydride was the previous generation - still good but with a bit more tendency to memory effect. Nickel-Cadmium - two generations ago, slower-charging, more memory effect.

Memory effect is what happens if you short-cycle the charging of your battery. Any battery will give you the longest life and best usage if you make a habit of running it down fully before you charge it up. If you make a habit of recharging the battery when it is, say, only half discharged, then it will "remember" this and after a while will only allow you that 50% of its full potential performance.

Even if you choose Li-Ion batteries, it's still best to fully discharge and fully recharge them regularly - even if you don't do it every time.

2. In general, yes. The higher the voltage the more "oomph" the tool will have. But this is not a hard-and-fast rule. For example, a very cheap 18V tool might not have as much power as a better-quality 14.4V tool, due to poorer gearing.

3. SDS has been explained above. If you buy an SDS drill, bear in mind a couple of things: (a) it isn't a replacement for an ordinary battery drill/driver - it does a different set of jobs; (b) if you do decide to get one, make sure it has hammer-stop and roto-stop. That way you can use it as a heavy-duty drill, and as a "kango hammer" type of tool.

7. A drill/driver will act as a drill and a power screwdriver. A combi-drill will do the same, but should also have the option of switching on a hammer-drill feature. This is mainly used for drilling masonry. Whichever type you buy, if you're using it for anything more than occasional light work, I would recommend you to ensure that it has two batteries. One can then be on charge while you continue working with the other.

8. You are absolutely right to avoid using a chainsaw unless you have received proper training or have plenty of experience with one. The Forestry Commission has a saying: "There is no such thing as a slight accident with a chainsaw".

You could use an electric reciprocating saw for cutting up logs, but I wouldn't recommend a B & D Alligator saw for this. I bought one a year or so ago, and I'm very unimpressed with its quality and durability. Whatever type you buy, bear in mind that you will only be able to cut logs of slightly less diameter than the blade length.

 

[Penners]

Sorry I've duplicated some of Flyfisher's advice. I was typing while he posting!

 

[Penners]

Try to standardise on a battery voltage and type so you can share batteries and chargers between all your tools and not make mistakes when charging. Charging a battery with the wrong charger can seriously reduce the life of the battery.

I hope FF won't mind if I just add a comment to the above good advice.

Don't make the mistake of thinking that, say, an 18V battery of one brand can be used in a tool or a charger of a different brand. Even if the batteries are of identical spec, they will invariably have a different shape or design of fitting.

 

[Pford75]

And for those that do have a chainsaw...I would recommend chainsaw gloves and trousers. Despite being well used to them, I had a saw kick down from a trunk I was cutting and touch the trousers (which instantly stopped the chain). Cost me £70 for a new pair....but the damage to my leg would have been more painful

 

[Flyfisher]

I hope FF won't mind if I just add a comment to the above good advice.

Not at all.

Don't make the mistake of thinking that, say, an 18V battery of one brand can be used in a tool or a charger of a different brand. Even if the batteries are of identical spec, they will invariably have a different shape or design of fitting.

Interesting point. I must have been lucky with my two 14.4v drill/drivers (different brands) as they have physically identical batteries that fit either tool.

However, one is Nicad and one is NiMH so I have to be careful to ensure I use the correct charger for each, which is a bit of a pain. It would be much more useful to have 4 identical batteries and two compatible chargers. C'est la vie.

 

[Lindyboo]

Many thanks to all for the wealth of info and advice - certainly very helpful and I'll take it all into account before buying. Just an additional couple of questions about power screwdrivers:

a) What's an 'in-line' screwdriver (this is the description for a DeWalt DW920K shown in the Screwfix catalogue)?

b) Any thoughts on power screwdrivers in general? For example, features to look out for or avoid?

Right, I'm off to enjoy a glass of port while also enjoying the log fire - best part of living in a period house, methinks.

Cheers!

 

[middi]

Another important rule when buying power tools is that you ( usually) get what you pay for. For everyday use a tradesman will normally invest in buying top quality portable power tools due to the fact that they last longer ( good quality metal gearing, Li-Ion batt. etc ), lighter in weight and more versatile in its function.
This kind of tool will last a few years.

A cheaper version ( or two) of the above will do a good job but a trade off must be expected. It depends on how often you need to use the tool will determine how long it will last.

 

[biffvernon]

Amps per Hour (Ah) or sometimes milliAmps per hour (mAh).

No 'per', he quips, pedantically.

 

[MdB]

Amps per Hour (Ah) or sometimes milliAmps per hour (mAh).

No 'per', he quips, pedantically.

And it means nothing without knowing the voltage either. Multiply the Amp Hours by the voltage to give the capacity in Watt Hours. Compare that.