Prusa i3 bleeding extruder

I discovered that my 3i often need like 10-20 mm filament feed at start of printing before any plastic get extruded
think it's due to that when warming up to 250 C before printing I get 20-40 mm plastic bleeding out of extruder
Guess I then get a void inside hot end that need to be filled up at the time I start print

Just don't know a good way to get this workin like automatic
At the moment I do manual feed of filament via LED display commands, just before printing
Anyone seen this problem. Anyone found more clever solution than my manual procedure ?
Ha det gött
Bosse

---

Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

I bed your hot end heats up first then stays hot while the bed heats up.
I do the reverse. I heat up the bed first (takes awhile) then home the machine then heat the hot end. Once its up to temp it prints. I only ooze about 2-3mm out the tip and that gets primed back in the first inch or so of my skirt.

Thanks Floyd for info I'll try that
You are right I have hot head at 250 C long before I get bed up to 100 C
Ha det gött
Bosse

---

Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

Hm, it's more like 50 - 100 mm bleeding really if you leave it like a couple of minutes on 250 C
Floyd's advise help a lot but still some startup extruder feed missing ....
Ha det gött
Bosse

---

Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden

Do a wider skirt or add a raft or even some gcode at the beginning to lift slightly and do an extrude to re-prime the hot end before it starts printing.

Ben

Yep I'll try that Ben ... Thanks for feedback
Ha det gött
Bosse

---

Prusa i3 Reworked, Delivered March 28 2014, RAMPS 1.4
Göteborg, Sweden