In article ,
"Doctor Evil" writes:

Wickes sell a 700w variable speed hammer drill for around £16 the last time
I looked. The variable speed means you can use it for driving screws, with
a bit of practice. Just the job. Most of the sheds sell plastic cases of

Cheap variable speed drills don't have the necessary torque or fine
control required for driving screws at low speed -- their output
power is very low at such speeds. However, the variable speed is
useful for starting a hole off slowly to ensure the bit doesn't move
before it starts biting into the surface. For this purpose, I found
the power controller in an older B&D drill much better than the one
in a newer Bosch -- the B&D can be started from almost zero, whereas
the Bosch has a nasty hysteresis which means the motor won't start
until you get the trigger to about 1/4 travel and you can then back
off to lower speed (a characteristic of a very cheap light dimmer
circuit).

You can get variable speed drills which deliver much nearer full
output power at low speeds and are good for screw driving, but you're
looking at a much higher price -- the power controller will include
servo feedback, thermal monitoring and power input control right up to
and including top speed operation, and is a lot more sophistcated than
the crude light dimmer type found in cheap drills.

drills and drivers for around £10-15

--
Andrew Gabriel