The way: how to make a soft starter for power tools with their own hands
Owners of hand-held power tools, both amateurs and professionals, are often faced with its breakdowns. It is not always the fault of the user. There are peculiarities that cause it to happen regardless of external factors. It depends on the technical perfection of the product, its price and area of application. The considerable part of malfunctions can be avoided even by using inexpensive power tools, if to execute their simple modification, for example, to make soft start.
Installation of a three-wire soft starter
It seems to me, but all powerful tool, especially similar machines should have soft starter in the base, but why manufacturers save on this penny function. I do not understand. Probably. decrease of reliability and increase of appeals to the service centers. the soft starters, judging by the reviews, sometimes burn, but not so often that they can be easily found on sale. no demand. no supply. I have found only one place, as a spare part for power tools, unknown to me of the brand HUMMER, and the catalog of the store indicates only what tool it is designed for. Existing in the workshop of a circular saw on metal Makita LC 1230 suits everything, but when you start it kicks and eats so that the light goes out, and thinking that the scheme of the PP from the angle grinder 2.2kW should fit into any of my tool in need of redesign, I ordered: HAMMER soft starter (46) USM2200B
The whole upgrade process filmed on the
Advice for those who decide to repeat this: 1. Perhaps the block I used from the angle grinder at 2.2 kW is too much for a 1.7 kW motor, pick up the nominal, judging by the forums, the use of a larger power unit increases the time of acceleration of the motor. 2. It is not difficult to disassemble the saw, but not the whole saw, just the part where the electronics are in the handle. 3. When disassembling will be 2 long bolts and one short bolt long into the holes above the motor, short into the hole next to the cable inlet. 4. When you separate the halves of the body can and most likely will fall out, the plastic part of the safety mechanism and the pin with the hook for the chain. 5. After you remove the button, it is better to seal the rest of the mechanism with mounting adhesive tape. 6. At once lengthen red and black wire of soft starter by pieces of wire of 30 centimeters on corresponding section.
Crimped all ends into lugs, this is what the result looks like
The unit fit nicely in the niche of the handle above the motor
Button with a larger mechanism, for those who still manage to crush it
This is the kind of mishap that happened in the process, laughed, bit it off and redid it, that’s why I don’t like ring crimps:
As a result, the unit cost me 411 shipping, took three pieces at once, you also need to put a block in the circular saw and angle grinder, not expensive, simple and extremely nice remake, I recommend.
All about soft start in power tools
It is well known, that not every tool is equipped with such soft starters. Mostly they go in expensive models of famous brands Bosch, Hilti, DeWALT. In both cordless and cordless versions.
Power tool without such a device has a bunch of disadvantages:
The gears hit each other and work faster
When working with a coping saw, the disk will not be dislodged from the prepared cutting point. Which is important for non-professional carpenters.
If you have a cottage or house in the initial stage of construction is not yet the electricity and you use a generator, then sooner or later you will realize that without PSU (soft starter) with a sharp initial currents, the generator will not last long. Therefore, it is able to save not only the tool but also the emergency power supply.
You can of course build a PSU yourself into the same angle grinder or slicer, but to disassemble the equipment and fumbling with the internals not everyone wants.
Plus, opening a new case entails the loss of warranty. So the best use for the KRRQD12A is an external connection.
Just keep in mind, it is suitable for collector motors. Asynchronous requires a frequency converter with different control principles.
This box is rated at 12 amps.
What is characteristic, the dimensions are the same, and the difference in price is a couple of tens.
It would seem better to take it, but for a standard 16A socket, the first option is more profitable. There will be no desire to connect a heavier load and thereby to burn all pins.
Chop saw tuning. Soft start module. at Home
Masters samodelkin certainly collect similar circuits and their own hands, based on thyristors BTA 12-600 or others, capacitors, a diistor and a couple of small resistors. You can find a lot of examples of wiring diagrams on the Internet.
But for the average tool user, it’s much easier to buy it all in a ready-made compact case. You can order the similar device from here.
Preparing to install the device
Making and using a small BCU will save money on the purchase of new power tools and extend the life of the old ones. For a domestic environment it is sufficient to use a 12A unit with the abbreviation KRRQD12A (see the following diagrams on the Internet). picture below).
Such a device should be used for starting and operating the collector motor types of power tools with power up to 2500 watts. When you buy a PSU, you must select an extension cord that is long enough to work. You also need to prepare a separate socket, a piece of multi-core soft copper wire, tools, heat shrink or electrical tape. Soldering iron, rosin and solder are needed if wires in the extender are soldered rather than bolted.
Types of soft starters
They can be divided into four categories.
- Regulating the starting torque. Their operating principle is that they control a single phase. But they do not reduce inrush currents when controlling the soft start. Therefore their range of application is limited.
- Voltage regulators with no feedback signal. They work according to a preset program and are among the most common to use.
- Voltage regulators with feedback signal. Their principle of operation is the ability to change the voltage and regulate the amount of current within a given range.
- Regulating current with feedback signal. Are the most modern of all devices of this type. They provide the greatest accuracy of control.