Fighting with computers

I have been losing a fight with my latest extuder/hotend combination. It works ok as far as I do not want it to work too fast. I want to keep the PG35L motor not too hot or it will break. So I am powering at 500mA, which seems to be well beyond its maximum rated current, so it gets hot. But I've added a passive cooler to it so won't get dangerously hot. Should I used a higher current, as someone suggested, maybe my mileage might vary, but at the expense of needing a fan blowing directly to keep the motor from frying itself. One of the things that was bothering me was the maximum printing speed I could use with this new setup on my Prusa i3. Extrusion speed on Pronterface software (the host I use) is user selectable but measured in millimeters per minute, while travel speed is usually configured in the slicing software in millimeters per second. But doing the apparently simple math of dividing by 60 will not help here, among other things because the extrusion speed is the 3m

I am very happy with the Prusa I built, and so I am with the Printrbot, which much smaller but it does a nice job too. In fact, most of the parts (on different shades of blue) of my new Prusa i3 have been printed with the Printrbot, but the black ones, which are ABS parts, have been printed with my Prusa. Having two working 3D printers seems to leave you in a difficult position to explain your wife why in hell you're building yet another one, but somehow I managed. I was curious to learn how this new version from Josef Prusa would do compared to what I was familiar with. I've done a short picture album of the process with some comments in them whenever something different or creative was done there. My first impressions are that this printer can work really fast and it seems very stable at high speeds. It feels much sturdier than the previous Prusa's and more stable than Printrbot. To its advantage has the reduced mass of the new compact extruder which I have not mas