Choosing a drill

Thank you for the reply Monkeh.

So, I've now got a Bosch GBH2400 on order to be delivered tomorrow. I'm happy with its spec, the recommendation and price. :)

Thanks for all the assistance.
 
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I have a 3kg class machine which has a "paltry" 750 watt motor and it drills faster than any impact drill I've ever used, including some of the 1000 watt monsters - instead look for impact energy,

older non electronic tools can seem much better and punch well above there weight
what some people don't realize is the electronic slow/variable speed control consumes around 25-45% off the input power
so and old 500w drill will turn into 720w when you add the electronics
and a non electronic sds may well turn from 750 to 1100w :cool:
 
what some people don't realize is the electronic slow/variable speed control consumes around 25-45% off the input power

If it did that it'd melt its way out of the case and your hands on the way.
 
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what some people don't realize is the electronic slow/variable speed control consumes around 25-45% off the input power

If it did that it'd melt its way out of the case and your hands on the way.

drill picked purely at random input power 701w output 385w
http://www.dewalt.co.uk/powertools/productdetails/catno/DW241/info/specifications/[/QUOTE]

That has nothing to do with the speed controller. The drill cannot operate at 100% efficiency.

If hundreds of watts of heat were dissipated in the trigger, it would melt.

Older drills are even less efficient.
 
There will be losses in any electronic speed controller, but not 3-50% Some serious heatsinks would be required.
Add in the loss of efficiency in converting electrical to mechanical force, then overall, yes it may add up to the significant loss.
 
There will be losses in any electronic speed controller, but not 3-50% Some serious heatsinks would be required.
Add in the loss of efficiency in converting electrical to mechanical force, then overall, yes it may add up to the significant loss.

The losses are small enough that the controller does not get significantly hot. The good ones get mildly warm during extended use. The cheap ones on B&Q crap get fairly hot and promptly stop working.

The motor itself is horribly inefficient. That's the nature of the beast.
 
There will be losses in any electronic speed controller, but not 3-50% Some serious heatsinks would be required.
Add in the loss of efficiency in converting electrical to mechanical force, then overall, yes it may add up to the significant loss.

The losses are small enough that the controller does not get significantly hot. The good ones get mildly warm during extended use. The cheap ones on B&Q crap get fairly hot and promptly stop working.

The motor itself is horribly inefficient. That's the nature of the beast.
That's what i was suggesting...or at least thought i was.
 
There will be losses in any electronic speed controller, but not 3-50% Some serious heatsinks would be required.
Add in the loss of efficiency in converting electrical to mechanical force, then overall, yes it may add up to the significant loss.

The losses are small enough that the controller does not get significantly hot. The good ones get mildly warm during extended use. The cheap ones on B&Q crap get fairly hot and promptly stop working.

The motor itself is horribly inefficient. That's the nature of the beast.
That's what i was suggesting...or at least thought i was.

I was just clarifying. And ranting about the B&Q crap people ask me to repair.
 
Unless you want molten copper on your floor, big heavy and expensive is the only way to go for transformers.
I've got to agree with you, there. There is no such thing as a cheap reliable transformer, although even Screwed-Up can beat that price and a quick pole about on eBay dropped the price even further. Go on the local flea market and you mght well pick-up a second hand one for £25 to £30 - that's how I bought my first one although it only lasted long enough for me to earn the cash to buy a new one.......

You can go a step smaller for simple drills though.
I reckon it's a bit of a false move for many tradesmen. Fine if you know that all you'll ever want to deal with is a 750 watt SDS or a small angle grinder, but with these things I think it's always best to forward plan. As soon as you start to do full house refurbs you tend to need a bigger transformer for tools like heavy breakers, mitre saws, paddle mixers, routers (try doing a mason's mitre kitchen worktop joint without one!) - if it's goyt a high rating on it or it's in use over extended periods the bigger transformer isn't an option.
 
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On refurbs, it may be you have no power, then what?
Generator. Carry one in the van at all times and sometimes two.
Bloody expensive option, though. I mean in running costs terms

I have a 3kg class machine which has a "paltry" 750 watt motor and it drills faster than any impact drill I've ever used, including some of the 1000 watt monsters - instead look for impact energy,
older non electronic tools can seem much better and punch well above there weight
Actually, B-A, the 3kg machine is a relatively modern soft start, variable-speed Atlas-Copco (now Milwaukee). For a relatively modest motor it packs a good punch because the design of the gearbox and hammer mechanism is just so much better than most current 2kg SDS machines and streets ahead of any impact drill regardless of motor size. The key is the superior efficiency of the hammer. Recently Bosch came up with a 2kg size drill which packs almost the same amount of punch - the GBH2-28DV - problem is it is actually a 3kg drill and it costs pretty much the same as many of the older 3kg designs. To my mind it offers very little extra
 
I have two 110v transformers one is a big 3.3Kva with two 16 amp sockets and I bought a small one that's easier to carry around that's a 0.75Kva rating and just gets used with my SDS drill.

Tend not to carry them on the van anymore as I have a 36 volt cordless SDS drill now.
 

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