I always wonder why nobody use stratasys-like hotends. They are without heatsink.
So this is my one. Simple, fast and effective.
400-500mm/min into air extruding ABS and PLA. It virtually cannot be jammed.
Thе barrel ( from old chineese hotend) is with PTFE tube inside. The tube can be inserted only from downside.

Edited 3 time(s). Last edit at 01/21/2016 05:16AM by karabas.

being " stratasys" there properly have a patent on it

but where it's bolted to the frame doesn't that make rudimentary heatsink?. but at 400-500 mm/s aint much time for the fila to swell and getting 400-500 mm/s out of a reprap extruder be a feat in itself.

The QUBD extruders are similar, and so are the extruders on the old Makerbots.

Cannot be jammed? Hmmmm. As I recall, the QUBD and the Makerbot extruders were jammed most of the time.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

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jinx
but where it's bolted to the frame doesn't that make rudimentary heatsink?.

???
Heated block is bolted not barrel.

Like with my merlin hotend the thread on the upper part of hotend is cooling it by increasing the surface area. In my old printer i use a Merlin without any fan in a heated chamber for years now.

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the_digital_dentist
The QUBD extruders are similar, and so are the extruders on the old Makerbots.

Cannot be jammed? Hmmmm. As I recall, the QUBD and the Makerbot extruders were jammed most of the time.

Disagree, they are not ever similar. Massive solid heatsink. Long nonheated part of barrel.

Keypoint of my design is short nonheated upper part of barrel. Possible jamming zone is about 2mm or less. Yes this zone can be considered as a rudimentary heatsink )
Barrel is made of steel. Brass didnot work for me. And I made nozzle shorter.

The disadvantages of the above are:
1 noncompatibility with Jhead/e3d type of mounting.
2 loading of filament requires funnel on the top of barrel for easy loading.

Edited 3 time(s). Last edit at 01/21/2016 06:47AM by karabas.

Did no one else notice the huge blower pointed at the threaded part of the hot end?
I dont like how its mounted. The heater cartridge is right near the mounting point soaking heat into the printer and the nozzle. Not really the best idea but if it works then good job.

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Floyd
Did no one else notice the huge blower pointed at the threaded part of the hot end?
I dont like how its mounted. The heater cartridge is right near the mounting point soaking heat into the printer and the nozzle. Not really the best idea but if it works then good job.

Blower is important.
You mean blower cools heater cartridge? Or transferes heat to unwanted places?

J-Heads don't have heat-sinks. Genuine J-Heads don't need heat-sinks.

The blower is cooling the threads of the insert just like a tiny heatsink.

What would be the benefit of a hotend without heatsink?

yeah ... not exactly a speed daemon, 500mm/min only equates to 8.3mm/sec which in printing terms isn't exactly what i would call fast personally i'm running between 60mm/sec and 90mm/sec and others run a lot faster

the only reason that hotend "works" is simply down to the ptfe tubing inside the stainless tube and you'll be getting a huge meltzone so i wouldn't expect retraction to be very helpfull

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Floyd
The blower is cooling the threads of the insert just like a tiny heatsink.

Agree.

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reifsnyderb
J-Heads don't have heat-sinks. Genuine J-Heads don't need heat-sinks.

PEEK part is about it.

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Frans@France
What would be the benefit of a hotend without heatsink?

Size (vertical) and simplicity.Unexpensive.
F.e. for deltas such as Atom-2 it does matter.

Edited 1 time(s). Last edit at 01/23/2016 03:36PM by karabas.

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thejollygrimreaper
yeah ... not exactly a speed daemon, 500mm/min only equates to 8.3mm/sec which in printing terms isn't exactly what i would call fast personally i'm running between 60mm/sec and 90mm/sec and others run a lot faster

the only reason that hotend "works" is simply down to the ptfe tubing inside the stainless tube and you'll be getting a huge meltzone so i wouldn't expect retraction to be very helpfull

Agree.
But stratasys(dimention) melting zone as twice as longer and retract works.

I want to try their nozzles.

BTW what hotends do you speed up to 60-90mm/sec?

Edited 1 time(s). Last edit at 01/23/2016 03:34PM by karabas.

I run my E3D-v6 at about 130 mm/sec, and could probably run it faster with a good extruder.

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karabas

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thejollygrimreaper
yeah ... not exactly a speed daemon, 500mm/min only equates to 8.3mm/sec which in printing terms isn't exactly what i would call fast personally i'm running between 60mm/sec and 90mm/sec and others run a lot faster

the only reason that hotend "works" is simply down to the ptfe tubing inside the stainless tube and you'll be getting a huge meltzone so i wouldn't expect retraction to be very helpfull

Agree.
But stratasys(dimention) melting zone as twice as longer and retract works.

I want to try their nozzles.

BTW what hotends do you speed up to 60-90mm/sec?

mine, see the link the signature

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epicepee
I run my E3D-v6 at about 130 mm/sec, and could probably run it faster with a good extruder.

PLA or ABS? what extruder? what temperature?
I am on direct drive now with D10mm drive wheel(gear)

The J-Head Mk III series had a heat-sink. PEEK is an insulator and a heat-sink was avoided by designing the part so as to avoid heat build-up in the first place. J-Heads from Mk IV through Mk 9 don't use heat-sinks.

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karabas

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reifsnyderb
J-Heads don't have heat-sinks. Genuine J-Heads don't need heat-sinks.

PEEK part is about it.