Adding a Soft Start Feature to Any Power Tool

In the past two decades Dewalt was making one of the best job site table saws in the market. During this time a lot of improvements were added, except one - a soft start. Every time I turn it on - it bangs like crazy and kicks all rpm from the start. 

The start is so brutal that the whole 26kg weight table saw moves a bit on the surface. 

Dewalt even added a motor braking feature - so why was the soft start option forgotten?

These days we are used to working with power tools that already have a soft start, so I’ll implement this feature by using this soft start module. This is a very cheap and simple modification, that could made to any electric power tool. I'll demonstrate it with my Dewalt table saw, but also I did the same procedure with Metabo miter saw too.

How I did it - you can check by looking DIY video or you can follow up instructions below.

For this project you will need:

Materials:

Soft start module XS-16/D3 also marked as JRR-01 Link to the product!

Spade terminals

Electric insulating tape

Short piece of electric wire

Tools:

Screw driver

Spade terminal crimping tool

Wire cutters

I’ll use XS-16/D3 also marked as JRR-01 Link to the product! soft start module, which I bought online. Number 16 represents the amp rating that could be handled. I was able to choose between XS-12/D3 and XS-16/D3, and since the price was the same I took the more powerful option. By the way, XS-12/D3 should work just fine if it is the only option that you could buy. This soft start module could be used for 120V and 240V power tools. I paid 9Eur, which is about 11 US dollars, which is really cheap.

To connect it I need to disassemble the power on-off switch. Before doing that make sure the table saw is unplugged from the power.

This is a simple 6 contacts on-off switch. Electricity comes from the outlet, goes to the switch and then to the motor. The whole action will be with those two pairs of wires and contacts where they are connected. Number 13 and 33. In general, the soft-start module should be connected in between those two on-off switch terminals and the motor. 

I don’t want to make any mess by cutting and soldering wires, so I used male and female spade terminals instead. This option will save power tool warranty too because it could be disconnected and will not leave any marks.

Disconnected both motor wires from the switch and connected soft start module in, regarding the provided diagram. Wire C should be connected to the motor blue wire.

Wire B should be connected to the power switch terminal 33.

And lastly, wire A should be connected to the motor brown wire and at the same time to the on-off switch terminal 13. I’ll use a Y shape splitter to connect two wires on the same terminal. 

Before assembling everything back, I used some electric tape on the exposed terminals. The assembly process is the reverse of the disassembly, only the soft start module should be fitted inside too.

And how does it work? Really nice. Let's compare it with a previous start. Kind a big difference. Please check the video how it looks and sounds. Link to the video!

The fact that it starts so slowly will significantly extend the life of the bearing and the engine itself, because it does not eat it with maximum currents and it does not blow the fuses with those that have bad electrical installation.