I used a step down module that makes less heat. The soldering heater requires 18 volts and has a FET in the power supply. But the fan and motor only need 12 volts. If you want to take care of the switch, you can use a car relay. I went the way to make the step down switchable. The fan got a 7810 for this. This is in the shrink tube.
I bought this desoldering station a few days ago, tried it and was satisfied. I saw this video and thought it might be a good idea to build this as shown. Indeed the fan is more silent but for some reasons my gun won't heat up correctly after that (only 190°C instead of 400°C and won't heat up again...). First I thought the gun is defective but when I bridged the LM7812 the gun worked properly?! After building back to original I checked the temperature at the tip and found that there is a difference (about 50°C-70°C) to the shown temperature at the display. It took about 30 seconds to reach the 400°C i've set before.
Thank you for the heads-up! I have that same desoldering station. Just opened it and checked, yep, 19 volts on that poor fan. But I solved it differently, I put two 47 ohms 1/4 watt resistors in series with the fan. That brought down the voltage to exactly 12 volts. Used two resistors to distribute the heat (total dissipated power is about 0,35 watts).
The best option for tight budgets is the Yihua 948, you can find then in Us$100 or lower price inclusive. Spare part gun Us$28 dollars. It is complete silence, everything works fine in this product. I bought one and works fantastic, is a real bargain. I recomend. Best Regards.
Looks also quite nice, in Germany it seems to cost just slightly more, than the ZD-915. But I also have to admit that the ZD-915 became much more expensive compared to what I paid for it almost two years ago. I paid 89€ and now it costs around 125€. The Yihua 948 looks to be starting at 135€.
Another option would be connecting a second 12V fan in serie to the first, and physically stacking them with longer screws. I have seen this solution in servers, so that if one fan gets stuck, the other still blows out hot air. Anyway I m going to order a desoldering station like this right away, so thanks for the reviews!
@@necro_ware WARNING!! the LM7812 output his 12v in the hit-sink screw ..... as you can see in the datasheet..... your chassis is 12v + live now 😟!! ... measured with the tester you see..
@@Ramdileo_sys That would be terrible! Luckily on the regulator L78S12CV which I used in this video the middle pin as well as the heat sink is ground. But of course people, who do this mod should pay attention to the pinout. Sadly, I didn't put a warning into the video, so you are absolutely right.
It s more or less one year that I own this desoldering station and I have to say it does a decent job for occasional users like myslef. The weak link is the gun, which started giving me problems after the first month and I think i will have to replace soon.
Glad I found this. My fan went from just being very noisy to a more grinding noise. Yeah, the wear and tear of over voltage finally caught up to it. It is also not the best fan to begin with, of course. I found a replacement that is just a small step up but I find myself needing to ask a question. Was the original fan blowing air in or sucking it out? There are no arrows on the original fan and I have already disconnected it. My new fan does indicate air flow direction. If I use any other application from past experience as an example, excess heat should always be sucked out. Just wanted to check in anyway.
i use the Ersa i-con vario 4 system... has a normal solder pen, soldering tweezers, a desoldering gun and hot air... was a little expensive but i'm really happy with it... great tools let you work with joy
Wouldn’t it be advisable to insulate the back of the 7805 against the chassis, as the back is connected to secondary ground. By mounting it directly to the chassis, you connect protective ( primary ) ground to secondary ground. Just mentioning...
I think you are on to something here - I tried connecting mine the same way and there is a 0.2V difference between the grounds. When connected my display shows "error" and fails to start the heater. When disconnected from the chassis it all works fine. Mine is a duratool branded model.
Well, I HAD the noise issue- I put in a step down converter for the resistor board and a relais to switch the pump. Now I run the pump and fan at 12,5v and the relais is switched by the gun. The pump became way snappier! Now the pump turns on next to instant, no lag anymore. And: CHECK THE POLARITY of the pump, mine was backwards wired. You don´t need the relais but without all the power needs to go thru the gun and the whimpy switch- I didn´t like that. The converter and the relais are rated for 5 amps because of the in-rush current of the pump. And do not forget the flyback-diodes because the converter might get damaged without them. Yes, it might be a little over complicated but it works flawless.
I thought about it, but the steal is quite thick and I didn't want to ruin the housing. My impression is, that it should be sufficient like that, but you are absolutely right, with a bigger hole the airflow would be even better.
Hi, I bought a ZD-915 spare desoldering gun for my mechanically defect AGT brand gun (same as Toolcraft TO-7863102 ?). Same look, other color. But the AGT has between Pin 1 and Pin 2 a measurable resistance of 47 Ohm (increasing with temperature increasing). What can you measure at your gun at room temperature? My ZD-915 spare gun is near 0 Ohm. Is a digital sensor in it or is the spare defect???
Very nice . Is there a fix for the desoldering gun ? The front side with the metal part gets really hot and melts the point where it meets the plastic body which melts and is not holding it firmly in place .
I guess, it's also an option. But 24V fans are not as usual and cheap as 12V. I think, it's cheaper to install a 7812. Furthermore, I think, that 24V fan at 19V will be not as effective, as 12V at 12V, but you have to decide, what's better for you.
My solution... a resistor with value 100 ohm 5 watt in the red wire of the fan. Fan now runs smoothly on approx 5 volts Greetings Erik ;-)
Great tip ! As mine also has a 12V fan, I've just replaced the resistive black box with a 5A DC-DC step-down converter.
I used a step down module that makes less heat.
The soldering heater requires 18 volts and has a FET in the power supply. But the fan and motor only need 12 volts.
If you want to take care of the switch, you can use a car relay.
I went the way to make the step down switchable. The fan got a 7810 for this. This is in the shrink tube.
I bought this desoldering station a few days ago, tried it and was satisfied. I saw this video and thought it might be a good idea to build this as shown. Indeed the fan is more silent but for some reasons my gun won't heat up correctly after that (only 190°C instead of 400°C and won't heat up again...). First I thought the gun is defective but when I bridged the LM7812 the gun worked properly?!
After building back to original I checked the temperature at the tip and found that there is a difference (about 50°C-70°C) to the shown temperature at the display. It took about 30 seconds to reach the 400°C i've set before.
Thank you for the heads-up! I have that same desoldering station. Just opened it and checked, yep, 19 volts on that poor fan. But I solved it differently, I put two 47 ohms 1/4 watt resistors in series with the fan. That brought down the voltage to exactly 12 volts. Used two resistors to distribute the heat (total dissipated power is about 0,35 watts).
The dropping resistors produce heat. A small buck converter would do the job more efficiently. All said, your way works, too. :)
Thanks I went ahead and ordered a step down regulator off Ebay so I could address this problem right away.
Did the mod. Helped a lot,much quieter now🙂 Thanks for the video 👍
You are welcome! Thanks for the feedback!
The best option for tight budgets is the Yihua 948, you can find then in Us$100 or lower price inclusive.
Spare part gun Us$28 dollars.
It is complete silence, everything works fine in this product.
I bought one and works fantastic, is a real bargain.
I recomend.
Best Regards.
Looks also quite nice, in Germany it seems to cost just slightly more, than the ZD-915. But I also have to admit that the ZD-915 became much more expensive compared to what I paid for it almost two years ago. I paid 89€ and now it costs around 125€. The Yihua 948 looks to be starting at 135€.
Another option would be connecting a second 12V fan in serie to the first, and physically stacking them with longer screws. I have seen this solution in servers, so that if one fan gets stuck, the other still blows out hot air. Anyway I m going to order a desoldering station like this right away, so thanks for the reviews!
Also an interesting way to solve that problem. Thanks for the idea.
should be the second fan a 6V fan?
@@zoltanbiro6388 I would add a 12V fan, or better one that has the same equivalent resistance as load
@@necro_ware WARNING!! the LM7812 output his 12v in the hit-sink screw ..... as you can see in the datasheet..... your chassis is 12v + live now 😟!! ... measured with the tester you see..
@@Ramdileo_sys That would be terrible! Luckily on the regulator
L78S12CV which I used in this video the middle pin as well as the heat sink is ground. But of course people, who do this mod should pay attention to the pinout. Sadly, I didn't put a warning into the video, so you are absolutely right.
It s more or less one year that I own this desoldering station and I have to say it does a decent job for occasional users like myslef. The weak link is the gun, which started giving me problems after the first month and I think i will have to replace soon.
Glad I found this. My fan went from just being very noisy to a more grinding noise. Yeah, the wear and tear of over voltage finally caught up to it. It is also not the best fan to begin with, of course. I found a replacement that is just a small step up but I find myself needing to ask a question. Was the original fan blowing air in or sucking it out? There are no arrows on the original fan and I have already disconnected it. My new fan does indicate air flow direction. If I use any other application from past experience as an example, excess heat should always be sucked out. Just wanted to check in anyway.
Thanks for tip. My solution... a resistor with value 100 Ohm 5 Watt. Soldered in the red wire. Greetings Erik ;-)
Fan runs smoothly on approx. 5 volt.
i use the Ersa i-con vario 4 system... has a normal solder pen, soldering tweezers, a desoldering gun and hot air... was a little expensive but i'm really happy with it... great tools let you work with joy
Nice. Time to open up my ZD-915 I guess.
Wouldn’t it be advisable to insulate the back of the 7805 against the chassis, as the back is connected to secondary ground. By mounting it directly to the chassis, you connect protective ( primary ) ground to secondary ground. Just mentioning...
I think you are on to something here - I tried connecting mine the same way and there is a 0.2V difference between the grounds. When connected my display shows "error" and fails to start the heater. When disconnected from the chassis it all works fine. Mine is a duratool branded model.
Apart from the heater possibly not starting (see above), what other negative effects could this have? Does it make the gun more dangerous?
Well, I HAD the noise issue- I put in a step down converter for the resistor board and a relais to switch the pump. Now I run the pump and fan at 12,5v and the relais is switched by the gun. The pump became way snappier! Now the pump turns on next to instant, no lag anymore.
And: CHECK THE POLARITY of the pump, mine was backwards wired.
You don´t need the relais but without all the power needs to go thru the gun and the whimpy switch- I didn´t like that.
The converter and the relais are rated for 5 amps because of the in-rush current of the pump. And do not forget the flyback-diodes because the converter might get damaged without them.
Yes, it might be a little over complicated but it works flawless.
Nice mod, I would also cut out bit with holes and replace it with metal grill. That should improve air flow even further.
I thought about it, but the steal is quite thick and I didn't want to ruin the housing. My impression is, that it should be sufficient like that, but you are absolutely right, with a bigger hole the airflow would be even better.
Interesting video, thanks for pointing out this issue!
Very nice !
I'll try that with mine once I have the time ^^
0:44 - WTF, I need this 😀
Hi, I bought a ZD-915 spare desoldering gun for my mechanically defect AGT brand gun (same as Toolcraft TO-7863102 ?). Same look, other color. But the AGT has between Pin 1 and Pin 2 a measurable resistance of 47 Ohm (increasing with temperature increasing). What can you measure at your gun at room temperature? My ZD-915 spare gun is near 0 Ohm. Is a digital sensor in it or is the spare defect???
4:10 are you sure it isn`t suppose to blow out hot air from behind?
Very nice . Is there a fix for the desoldering gun ? The front side with the metal part gets really hot and melts the point where it meets the plastic body which melts and is not holding it firmly in place .
Hm, I don't know. I honestly don't have such problem. In my case everything seems to remain in place...
@@necro_ware Maybe it's just me . I might have misused it and put much force with an angle trying to desolder capacitors .
How about changing out the fan to a 24v version?
I guess, it's also an option. But 24V fans are not as usual and cheap as 12V. I think, it's cheaper to install a 7812. Furthermore, I think, that 24V fan at 19V will be not as effective, as 12V at 12V, but you have to decide, what's better for you.