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Crystal Clear action run.png

Release status: working

RescoHotend all.jpg
Description A full metal hot end.
License GPL
Author DarioCorsetti
Based-on [[]]
Categories Extruders, Hot End
CAD Models
External Link



Hot-end fixed to the extruder

When you have extruder problem, one of the most scaring doubt is: "it's something related to plastics parts?". Usually extruder use PTFE or PEEK as insulator and/or sleeve and this parts and soften or melt. This limit the extruder maximum temperature. So I want a full metal extruder and I made one. I this was this post to give me the first inspiration.


  • All metal parts
  • Easy to assembly (only three parts, no glue)
  • Really solid assembly
  • Aluminium block heated by glass resistor
  • Interchangeble nozzle
  • Simple mounting plate (compatible with mendels parts mount)


  • Forced convection is needed to cool down the cold-end
  • In theory greater friction due the miss of PTFE sleeve can limit print speed. In practise I can print on my RepRap Prusa i2 0.4mm layer height of ABS at 60mm/s without problems. Print speed is a value determined by to many parameters, I have yet to find a good measure of this aspect



The nozzle is made of brass.



The coldend is made of stainless steel, in order to minimize heat transfer. The fins act as heat sink, while the material between them is thin as possible to increase heat resistance.

Stainless steel cold-end

Heater block

The heater block is made of aluminium and houses a 5mm diameter glass resistor and a axial thermistor. We use a 100K 1% resistor (104JG1FRA), the temperature table (taken using the less precision method you can image) is:

#define NUMTEMPS_3 62 short temptable_3[NUMTEMPS_3][2] = { {1,846}, {32,295}, {34,290}, {37,285}, {39,280}, {42,275}, {45,270}, {48,265}, {51,260}, {55,255}, {60,250}, {64,245}, {69,240}, {74,235}, {80,230}, {87,225}, {94,220}, {101,215}, {110,210}, {119,205}, {129,200}, {140,195}, {152,190}, {165,185}, {180,180}, {196,175}, {213,170}, {231,165}, {252,160}, {273,155}, {297,150}, {322,145}, {349,140}, {377,135}, {407,130}, {439,125}, {472,120}, {506,115}, {541,110}, {577,105}, {612,100}, {648,95}, {683,90}, {718,85}, {751,80}, {782,75}, {812,70}, {840,65}, {865,60}, {888,55}, {908,50}, {926,45}, {942,40}, {956,35}, {968,30}, {978,25}, {987,20}, {994,15}, {1000,10}, {1005,5}, {1009,0}, {1018,-20} };

Alluminium block

Mounting plate

The plate is made of iron, you can use every type of metal stiff enough.

Mounting plate


The following is a link to a Youtube video of the extruder assembly. The part relative to the hot-end start at 1:10

The extruder


Part Link
Heater block


R.eS.Co. research RescoHotEnd