For years I’ve been using a 19.2V Porter Cable drill for many of my projects including some launcher work. Removing valve screws, tapping pressure chambers, etc. It has been a real workhorse. It is still going strong even after all these years. On the original NiCad batteries. It pays to take good care of your batteries.
Recently I decided to upgrade to Lithium. Lithium Iron is the coming technology, and I use it for powering Radios in the field. One manufacturer makes battery tools with Lithium Iron and has for years. The rest of the tool vendors use Lithium Manganese which is almost as good.
I tried one of those yellow tool sets with the Lithium Iron batteries, but the PWM whistle was so loud it almost demanded ear protection, and the motor speed was uneven. The LED only operated when the motor was running.
So I moved on to the Makita. Yes it cost a few dollars more, but not much, and it came with three times the battery amp-hour capacity and it also included a third battery. The set included a drill-driver with clutch that even has a hammering mode, and an impact driver. Of course there is a charger and a hard plastic case.
The refinements on these blue Makitas are really top drawer. The gears shift easily, even when the motor is completely stopped. The LED lights at a touch of the trigger and stays on for awhile. The PWM motor speed pulsing is almost inaudible. The slow speed control is excellent. The chuck really locks on to the bits. The drill with battery weighs just over four pounds, almost two pounds lighter than the old 19.2V NiCad unit.
The impact driver is a new tool for me. With triple the torque of the drill it is capable of doing amazing things with screws. I spun out 120 screws from a case of valves and it took much less time than with the drill. There is much less torque reaction to it is easy to hold onto the parts and the drill and it does not tend to jump out of the slots and mar the screwhead. It develops 1300 inch pounds of torque and it also spins at high speed when the screw gets loose, without changing gears. So it speeds up screw handling as compared to a drill-driver. And it weighs just over three pounds, lighter than the drill! This is an amazing tool.
NOTE – DO NOT use an impact driver to put screws into valves. They are fine for removing them but for installing them the control of a hand screwdriver or a drill driver with low RPM and a clutch is required. Breaking the valve body is very expensive and to be avoided…
It is so enjoyable to work with good tools!
NOTE – the one problem with all of these new Lithium Ion powered tools is battery failure. These are expensive batteries and people are understandably unhappy when their batteries don’t last as long as they expect. So what can you do?
Lithium batteries are different animals. Running them down too far can ruin them as can overcharging them. Most tools are designed to prevent this (or the protection is built into the battery pack), that’s why the tool shuts off suddenly without losing power. The battery protection kicks in. There is no danger of memory with Lithium, so you don’t have to run them all the way down. Good quality chargers will not overcharge them.
But there are a couple of new surprises in the Lithium long life maintenance strategy. Two other things are very hard on Lithium Ion batteries. HEAT, and FULL CHARGE. You want to minimize or avoid both of those. The two together can kill batteries in a hurry.
Lithium batteries last much longer if they are never charged above 90%. Agencies that need long life from their batteries do this. It reduces capacity a bit but prolongs life. So what is the ideal charge level for longest life? It varies but generally is 50-70% of full charge.
Heat is also hard on batteries. They age much faster when heated. If they are fully charged in a cool environment and then heated up THEY BECOME effectively OVERCHARGED which is a major problem for Lithium and shortens their life very quickly. They can be ruined in a few days.
So what to do? Chargers exist that will bring batteries to storage levels, charging or discharging them as needed. You can find these in the Radio Control world. But they are not really easy to use on tool batteries and probably void the warranty. All the tool chargers seem to go for 100% charge and give no other options. But we do have choices as to when to recharge. DON’T recharge before putting lithium batteries on the shelf unless they are dead. We want to stay away from empty and full charge. DO charge right before a big job, but DON’T charge cool and then take the batteries to a much warmer jobsite. Charge at the temperature they will be used. Try to put the tools away with the batteries in that 50-70% charge range.
Another tool to control charge state is that flashlight tool. It has predictable runtime so you can charge a battery fully and run it for 25% of the runtime and have a battery at 75% charge. On the Makita this is a one hour run of the light.
DON’T store the batteries in a hot place – car, garage, etc. Store them cool and 50-70% charged and they will last for many years.
On to Launchers. Making lots of parts. We should ship a lot of launchers in the next couple of weeks since the parts have now come in. There is still some machining to do, and building for assembled launchers.