Hi Mickman, My issue wasn't due to the version of the Sanguinololu; rather the quality of the PCB Heatbed. My PCB has a considerably lower resistance than would normally be required (0.85 ohm rather than 1.5 ohm); so to raise it to a high enough temperature, considerably more current has to be pumped through. While the current is within the specs for the MOSFET, it had no way to deal with the hby Taint - Sanguino(lolu)
Hi M4k, Apologies again for the delayed response. I suspect you're unlikely to need such a large heatsink; as was discussed above, my heatbed seems to have particularly low resistance and it does generate quite a bit more MOSFET heat than normal. I also supplemented my heatsink with an 80mm case fan; which I attached to the top of the ABS box I mounted my Sanguinololu in. Mounting the Sanguinolby Taint - Sanguino(lolu)
Hi Merlino4000, Sorry for the delayed response; I've been a bit busy the last couple of nights. I managed to get back to the printer tonight and I've taken a couple of photos as requested; I'll post the links below. I found that the easiest way to connect the source was to crimp the wire onto the MOSFET before soldering it to the Sanguinololu. I cut off the drain pin to give me a little space;by Taint - Sanguino(lolu)
Back with a quick update. Mounting the MOSFET on a heat sink and changing the wiring has done the trick; I've just spent the last week trying to get it to print; most of what I was getting was just garbage. I even managed to melt my first NTC Thermistor and had to scrape the remains off the J-Head; thankfully I had a spare For the heat sink, I cut up an old Aluminium CPU heat sink which had a tby Taint - Sanguino(lolu)
Ok, so one pin to re-solder to the PCB, one to cut off (to open up some space and avoid confusion); as we're going to use the ring connector, and one to connect to the ATX ground. I may also have to look at some form of strain relief to ensure that the remaining pin doesn't exert too much force on the PCB. I have the PCB mounted on some ply; so I'll probably just attach some form of support to tby Taint - Sanguino(lolu)
Ok, I'm going to dumb this down a little further; just so I'm straight on this and before I nuke the Sanginololu as well. The connections I believe I should be making are: ATX +12V --> Heatbed in Heatbed out --> MOSFET Drain Ring MOSFET Source Pin --> ATX Ground The other two MOSFET pins should remain connected to the Sanguinololu PCB? I'm assuming that the Sanguinololou will apply a vby Taint - Sanguino(lolu)
Ok, I'm currently using 1.5mm heat resistant flex, so it should hopefully be enough for the current; but you lose me a bit on the circuit description. I'm using an old 350W PC power supply which is rated for about 26A on the 12V line. I'm assuming that I need to run some wire from the main ATX motherboard connector to a connector block? I have a 15amp block available, but I'm not sure how I'dby Taint - Sanguino(lolu)