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Re: interesting Pololu burnout - 11 years ago
I was powering the VDD from USB. It might be that USB is enough to fry them. If I remember correctly the smallest 78L05 is 100mA the usually people use the 500mA version, but 500mA is USB also and that was enough to kill them. So I suspect 100mA is the number to aim to. So feeding them using a 50 ohm current limiting resistor should work. Spec sheet say's that the logic uses about 8mA so that wby stevep - Controllers
interesting Pololu burnout - 11 years ago
I have come across an interesting failure mode on the a4988 Pololu drivers. The driver clamps Vdd to ground and shorts circuits the logic power supply. It has happened to me twice and I have no idea what caused it. Does the A4988 drives have some special Vdd Vmot powerup requirements? After this the driver stops being a stepper driver and starts being a quite expensive resistor. I am quite puzby stevep - Controllers
Re: Choosing a Hot end - 11 years ago
The V4 does not really need a fan for ABS but for PLA it is mandatory. I used a V3 without a fan for some time, but I was plagued with jams on long prints. The hotend would jam after 3-4 hours of printing. After I added a fan to V3 the problem just vanished. For V4 and pla it jams in 15 or 20 minutes without fan. So running without it is NOT recommended. I use a 40mm 12V fan from a pc shop. Itby stevep - Reprappers
Re: Choosing a Hot end - 11 years ago
I have an arcol V3.1 and a arcol.hu V4.0. I had some leakage problems with the V3.1, but it survived 6kg of PLA. About the V4.0 hotend, I can only say WOW. All structural components are steel. All the high temperature parts are steel. I can reliably print with 265C with no ill effects. No leaks or breakage. There is one disadvantage to the V4.0 hotend. You have to make sure that your filament iby stevep - Reprappers