Update on the burning MOSFET situation.
After getting advice from all over the place, it seems that the MOSFET from Aliexpress is most likely the culprit, and not the schematic. So I got myself the same IRLS3034 MOSFET from Mouser. See how different they look. The one from Aliexpress is on the left, the one from Mouser on the right.
After soldering together a new board with whatever I could salvage from the burnt one, I finally found time today to hook it up for a test. The picture shows the board running with both heat bed and hot end being heated (see the two red LEDs).
And good news! The IRLS3034 MOSFET from Mouser did not burn! So it was Aliexpress component at fault after all. I managed to heat the heat bed up to 70 degC. While the area around the MOSFET did get hot, nothing burnt. I threw in a heat sink just to be safe, since without the heat sink, temperatures were reaching 110 degC. Still, with the heat sink, the area around the 20A fuse was getting to around 110 degC. I don't know, maybe the heat is being generated by the fuse.
I am just happy that the heating circuit is working.
Lesson: Some components can be bought from Aliexpress. But for critical parts (high current stuff, or when very precise values are needed), go for a distributor like Mouser and Digikey.
Next would be to find out why the motors are not working... could be because I blew the stepper drivers, but I can't be sure. I will have to find time to work this out.
Note: Issue fixed (see comment). Pre-launch version now available here. Some information on this has been updated here.
After getting advice from all over the place, it seems that the MOSFET from Aliexpress is most likely the culprit, and not the schematic. So I got myself the same IRLS3034 MOSFET from Mouser. See how different they look. The one from Aliexpress is on the left, the one from Mouser on the right.
After soldering together a new board with whatever I could salvage from the burnt one, I finally found time today to hook it up for a test. The picture shows the board running with both heat bed and hot end being heated (see the two red LEDs).
And good news! The IRLS3034 MOSFET from Mouser did not burn! So it was Aliexpress component at fault after all. I managed to heat the heat bed up to 70 degC. While the area around the MOSFET did get hot, nothing burnt. I threw in a heat sink just to be safe, since without the heat sink, temperatures were reaching 110 degC. Still, with the heat sink, the area around the 20A fuse was getting to around 110 degC. I don't know, maybe the heat is being generated by the fuse.
I am just happy that the heating circuit is working.
Lesson: Some components can be bought from Aliexpress. But for critical parts (high current stuff, or when very precise values are needed), go for a distributor like Mouser and Digikey.
Next would be to find out why the motors are not working... could be because I blew the stepper drivers, but I can't be sure. I will have to find time to work this out.
Note: Issue fixed (see comment). Pre-launch version now available here. Some information on this has been updated here.
1 comment:
I am stupid.
The motors were not working because I forgot to put in the jumpers below the stepper drivers. The board's design requires connecting a jumper to close RST and SLP when using A4988 drivers.
The motors are now working. Time to find time to try a test print. And work on the enclosure to allow better cooling below the board.
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