# Question about the MK8 Extruder

I am trying to make a 3D printer (Prusa i3 model). I was testing all steppers and all steppers are working, however the Mk8 extruder (direct drive) is not working and I don’t know why. Can someone help me?

• Mk8 just says "iteration 8", but at this time that is usually shorthand for the "Makerbot MK8" Hotend/extruder design. The Prusa i3 Mk3 swapped to the previous Makerbot Mk8 for an e3D v6 hotend some years ago. – Trish Dec 6 '19 at 15:46
• What firmware are you using? Chances are, you've forgot to disable the rather useless "cold extrusion prevention" if you're using Marlin. – towe Dec 9 '19 at 8:10
• Have you heated up the hotend to at least 170 °C? Or disable cold extrusion prevention with M302 S0? – 0scar May 4 '20 at 14:26
• Have you found and fixed the problem? If so, has the answer below led you to the solution? Please vote to accept the answer so this question is not bumped up once in a while and can be removed from the unanswered question list. You may even add your own solution and accept that after 48 hours! If you have not been able to address the problem please update your question. – 0scar Sep 1 '20 at 19:01