I'll answered it later in 'references' post. The 'impact' feature will increased the torque without lowering the motor's speed. Normal drill driver's motor speed will decrease when higher torque is needed. If the motor speed slows down, the effective torque also decreasing, until it cannot turn the screw anymore.

I saw a few cordless drill  models at Living Depot@Bangi, and usually expensive. I think the 'expensive price' is not popular in Malaysian market.

Yes, you can use rotary hammer (drill only mode) to drive screws. BTW, IMHO, HR2470 is not too heavy, at 2.6 kg, which is about as heavy as a brick. There are a big and heavy cordless drill driver which can reach almost 4 kg!! The problem is, the rotary hammer is long, and quite difficult to control the screw driving. If it is a long and big bolt using hex socket, it will be not much  problem using with the rotary hammer.

Thank you for the suggestion. Actually, I tried to drive the screw as FAST as possible, and the result is, what you can see in the video. Freestyle twisting.. I can put enough torque, but cannot twist quicker with the mini ratchet. Another feature of the mini ratchet is, it also come with hex socket wrenches. Next time, I may put some pictures how to use socket wrenches using impact driver and mini ratchet. It is nice small tool which I can carry along outdoor.

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Added on March 5, 2012, 4:57 pmI only can see and admire the electronic pulse impact driver, Hitachi WM18D... The price is 74000 yen, or about MYR 2750 .... Wow..... The price for technology.

Yes, the motor spin backward a bit, if the it's detects the screw bit is stopped, and start spinning forward again, the momentum creates the 'extra' torque. The man torque of 33Nm is not as much as 170Nm of the normal impact driver, but enough for most of the DIY's screw driving. But see how quick and silence  it can drive screw. Since it is fully electronic control, it has very low wear and tear, but, once the electronic parts damaged,.... it is just a MYR2750 paperweight. .. Still loving my cheap corded impact driver. heh eh e.

Correct,  but, we cannot get anything from 0 RPM (no spinning) ... The motor must spin to be useful.



Ref:
http://www.fastelectrics.com/elecmotorbasics.htm

I remember got 2 types, 1 big and another smaller one.
I cant find the price tag, so not sure which one you bought.

I got myself a china brand SDC, 27Nm only  , Li-Ion battery powered, I am loving it. 
Cheap and satisfied.

Some pretty nice tools to have. 1 size fit all (almost).

and probably dirt cheap compare to here
i want to go live in america 

If you want to live in America, you got to live outside the city. Those outside city area are really good.  Thing is cheap. But not the land and tax.

Or just get a motorhome. Motorhome are pretty common and almost every household outside city have it as recreation.

Want to live in city, better in MY.

I'm the senget DIYer 

I must live in the city wan. Preferably Las Vegas
But summer months, I need to go somewhere cooler.

July month - bad idea. Too hot. The nights is hotter than our afternoon sun *pengsan*