If you haven’t heard of oil impulse drivers, then join the club. I hadn’t either until I stumbled across this tool on the web and then later saw it at the STAFDA show. Oil impulse drivers are typically used in assembly plants and are usually pneumatic. But Makita has developed one (XST01Z) that runs on battery power (18 volts) and will be selling it for use on the jobsite.
The defining feature of this (and any other) impulse driver is how quiet it is compared to impact tools. According to Makita it produces 77 dB to the standard impact driver’s 82 dB or more. The difference is greater than the numbers suggest because the decibel scale is logarithmic. An increase of 10 dB is perceived as a doubling of the noise level and represents 100 times more sound intensity. The first video below is of a Makita oil-impulse driver (an earlier 14.4-volt model) and will give you some sense of how quiet these tools are.
I won’t pretend to understand exactly how the oil-impulse mechanism works. You can see for yourself in the second video below, which includes an animation of the tool’s inner workings. The video was posted on the Makita Australia YouTube page; the same tool will be sold here but it will have a different model number.
Impulse drivers make for quick and precise fastening, spinning the driver bit at high speed before the fastener is seated and automatically slowing down as they become seated. It’s worth noting that the Makita oil impulse driver tops out at 355 inch-pounds of torque, just a small fraction of the power generated by the company’s impact drivers (which produce more like 1,400 inch-pounds). It’s best suited to tasks and workplaces where precision and low noise are more important than having maximum power.
The XST01Z has a 3-speed selector and Quick-Shift mode, an electronic function that automatically downshifts and reduces power and speed prior to driving fasteners home. It’s intended to minimize screw thread stripping, screw breakage and damage to the work. With a head length of only 5 3/8 inches, it is exceptionally compact for an 18-volt tool. The Oil Impulse Driver is scheduled to be released in the winter of 2015. Pricing has not been announced.
Battery: 18-volt LXT
Modes: 3 speeds plus Quick-Shift
Speed: variable; 2,700 impacts per minute (maximum)
Maximum torque: 355 inch-pounds
Head length: 5 3/8”
Weight: 3.2 pounds (w full size battery)
Available: Winter 2015