Hot Flow is our term for filament-based materials which are deposited at over 150°C, depending on the head.
Note that at present, our Hot Flow heads work with 1.75mm filament (actually, 1.6mm to 1.9mm), but not 3mm filament.
Materials for Hot Flow
The following materials can be printed from Hot Flow heads.
- ABS (Acrylonitrile Butadiene Styrene)
- Flame Retardant ABS
- ABS - PC Alloy
- Conductive ABS
- Smart ABS
- Flex 45
- HIPS (High-Impact PolyStyrene)
- Taulman 618, 645, 910
- PC (PolyCarbnoate)
- PEI (PolyEtherImide) - AKA Ultem
- PEEK (PolyEther Ether Ketone)
- PET (PolyEthylene Terephthalate)
- PETG PolyEthylene Terephthalate Glycol-modified)
- PLA (PolyLactic Acid)
- EcoFlex PLA
- Conductive PLA
- SS PLA (Stainless Steel infused)
- PP (PolyPropylene)
- PVA (PolyVinyl Alcohol)
Heads for Hot Flow
Hot Flow is available through the following heads:
- General MK Series Videos:
- MK1-250 Extruder for Standard Filament Videos:
- MK2-250 Extruder for Flexible Filament Videos:
- MK1-450 Extruder for High-Temperature Filament Videos:
- Loading and Printing
The following table compares the properties of the various Hot Flow heads, including which heads are recommended for which materials. The MK1 heads drive matieral from one side, with a spring-loaded bearing system to maintain pressure and positioning. The MK2 heads drive the material from both sides, and are designed for more flexible filaments.
|Head||Min Temp||Max Temp||Filament Type||Nozzle||Recommended For|
|MK1-250||150°C||250°C||Standard||.35mm, .50mm, .75mm, 1.0mm||ABS, HIPS, LayBrick, LayWood, Nylon, PC, PET, PETG, PETT, PLA, PP, PVA, T-Glase|
|MK2-250||150°C||250°C||Flexible||.35mm, .50mm, .75mm, 1.0mm||BendLay, EcoFlex PLA, FilaFlex, Flex45, Ninjaflex, PlastInk Rubber|
|MK1-450||275°C||450°C||Engineering||.50mm, .40mm, .30mm||PEEK, PEI (Ultem), PEKK, PPSU|
Research Papers Citing Hyrel Hot Flow
These are now listed by year here.
Firmware Versions for Hot Flow Heads
As of May, 2018, the following versions should be used for Repetrel versions 2.x and 3.x:
Use _FIL_250_PLAT_1A.hex :
- For MK1-250 and MK2-250 heads.
Use _FIL_450_45A.hex :
- For MK1-450 heads.
Use _FIL_250_RED_235A.hex :
- For older MK1-250 heads with RED RTDs.
Settings for Hot Flow Heads
Non-Hydra units shipping through spring 2017 ship with Repetrel version 2.x. Hydra units, and other units shipping as of summer 2017 will have version 3.x, and should consult the version 3.x tables, below. All units should be upgraded to 3.x when it is available. If you run a head with v2 settings on a v3 install, the background will flash red; please make the two changes below:
|Values for version 2.x will be inicated in this manner.|
|Values for version 3.x will be inicated in this manner.|
Some settings for the MK-Type heads (like temperature, prime/unprime values) will vary, depending on what material you are printing with. Nozzle diameter should accurately reflect what nozzle you have loaded (0.5mm is default) AND what path width you sliced for (recipe path or extrusion width should be nozzle diameter plus 10%). Having said that, here are our default shipping settings:
(formerly -350 or -400)
|Feed Rate %||1.000||1.000||1.000||1.000|
| Prime |
Please note that Prime values will vary greatly from those shown, depending on the flexibility of your material.
|Dwell Time (ms): v2.x||20||20||20||20|
|Dwell Time (ms): v3.x||35||35||35||35|
|Before Tool Change||2||2||2||2|
| Unprime |
Please note that Unprime values will vary greatly from those shown, depending on the flexibility of your material.
|Dwell Time (ms): v2.x||15||15||15||15|
|Dwell Time (ms): v3.x||-35||-35||-35||-35|
|After Tool Change||2||2||2||2|
|RTD Type||1 Meg||1 Meg||1 Meg||1 Meg|
(formerly -350 or -400)
How to disassemble the nozzle from the MK1 head:
- Heat to the printing temperature of the material loaded.
- Move the manual lever to the left, retracting material until it is free of the hobbed shaft, then remove by hand.
- Turn off heat to the head and remove it from the yoke.
- With a 1/4" driver or wrench, remove the nozzle.
- Inspect the nozzle cavity for any stray material; if found, remove with tweezers, solvent, air pressure or other means.
How to reassemble the nozzle on an MK1 head:
- Ensure your MK1 has no filament loaded.
- With a 1/4" driver or wrench, attach the nozzle.
- Use normal procedure for heating and loading filament.