Duratool de-soldering station

The Duratool de-soldering station is a rebadged ZD-915. There are several videos around showing modification to the system. I borrowed from them and hopefully improved the overall working of the unit.

De-soldering Station
De-soldering Station

I did these modifications some time ago now, but I recall the mains was switching the neutral and the switch was wired first and then the fuse. I corrected this wiring live to mains fuse and then through the switch. I think I also lowered the mains fuse.

The power in a unmodified unit steps the voltage down from 24 Volts to about 18 Volts via resistors. For the Fan and Pump the resistors are inside as plastic box at the back of the unit. For the front Panel the resistors are located towards the rear of the power supply PCB.

As many have done I removed the resistor network in the black plastic case. I separated fan from the pump circuit and installed a buck converter for just the pump. The pump motor is only on when the trigger is pulled so I am running this about the rated voltage which is for continuous use. I set this for now to around 18 volts. The suction feels more instantaneous now, maybe that is just my imagination.

I installed a second smaller buck converter to supply the fan and the controller PCB. To do this I took the output from before the power dropping resistors and fed it to a buck converter set for 12 volts. I am feeding the 12 volts from the buck converter to both the fan and the controller PCB.

As a result the fan runs less noisy. Hopefully the electronics and create less heat. Like others have done I elected to remove the internal shielding of the power supply. Which should allow for better air flow. Maybe at the cost of a little more radiated electrical noise.

I think it was a post on the “eev blog” that mentioned the heater was not set correctly on a unit they had. I checked this on my unit and found it to be running at a low maximum temperature. It did not take too much to figure out there was a potentiometer on the controller to set the thermistors sensitivity. After adjusting this I ran a series of tests to get the unit to heat to 480 degree centigrade. After doing this there was some overshoot. I adjusted a few times until I got to a place where I can set the gun to 500 degrees centigrade without overshooting too much. I have a spare element and as spare gun so as long as I don’t melt the unit all should be good.

I have one of the older style guns which are a little harder to clean and tend to clog the filter at the end of the gun. The cloth filter has metal disc with just a couple of notches out of the side for air flow. I assume the disk is there to prevent the solder instantly sticking to the filter and blocking all the air flow.

I have removed this disk to allow more airflow through the gun. Instead of the solid disk I am using a small wad of brass soldering iron tip cleaner.

The net result of all these mods is the cheap de-soldering station now actually performs like I had hoped it would when I first brought. And it is a little less noisy too.