Hey everyone. I have a prusa i3 with Ramps 1.4 and cannot get it to power on without plugging the Arduino into a 5V USB power supply. I have both diodes (D1/D2) installed and I have a 12V 30A psu purchased from Amazon (http://www.amazon.com/Universal-Regulated-Switching-Computer-Project/dp/B00D7CWSCG/ref=sr_1_1?ie=UTF8&qid=1397876792&sr=8-1&keywords=12v+30a). I also have a reprapdisby wumbo6 - RAMPS Electronics
I dont use any z retraction during my prints. It may be more general of a problem than I had first thought. My prints are now skipping in the x&y axis at much lower heights now. I have upped the pots on both drivers and am printing something to test it out. Does anybody know if drivers have been known to go bad over time? These are genuine pololus but have only installed these heat sinksby wumbo6 - General
I had a ton of cooling on it. All my steppers had heatsinks on them, I had a 120mm fan blowing on the boards a few inches away as well as a regular sized house fan on max for the entire duration of the print. I was also printing from SD so i'm assuming I can rule out the computer not sending commands quick enough. I guess a possibility is that the heat is not conducting well enough to the heatby wumbo6 - General
Thanks for the response! The bed is pretty hard to stall with my hand when it is moving. I will give it a try anyways. As for over extrusion, I am using 3mm filament and using a multiplier of 95%. Any other possibilities?by wumbo6 - General
Hey guys. I have been working on getting my prusa i3 to print more consistently. It has been going fairly well with small prints, however today while printing an extra x-carriage I ran into this issue. The print seems to be shifting/skipping at high layer heights when it is almost done. I adjusted the driver pots so the vref is about 25% higher than the voltage it needs to move(approx .2v forby wumbo6 - General
So I replaced the fuse with a piece of wire and put the 15A automotive fuse on the power line of the 11A input. Still getting the same thing. The mosfet is getting crazy hot although the hotbed is getting to a higher temp. Presumably since the fuse isnt limiting it keeping it from turning itself off. I didnt dare to test how high I could get it. So now I guess the only options are the heatbedby wumbo6 - RAMPS Electronics
I don't have an ammeter on my multimeter But so far i've checked that all the connections are tight and not anywhere they aren't supposed to be. I'm getting 0.9 ohms across my heatbed. And i'm getting continuity on my F2 fuse when the heatbed is turned off. One thing i've noticed is that I am getting a 260 ohm reading on my d2 diode in both directions. I bought the 15A fuses but havent instalby wumbo6 - RAMPS Electronics
Sorry to bring back an old thread. But did you ever figure out what happened? and what you did to fix it? I just started having this problem today after cleaning up some wiring. Every time I turn my heatbed on it the F2 fuse gets super hot. The bed temperature reading on pronterface gets to about 42 degrees then slowly goes back to room temperature. I've tried enabling and disabling PID bed cby wumbo6 - RAMPS Electronics