Noozle size and speed

Hi. I hoe this is the correct section of the forum for this question; I have this "issue": I have a filament,a sort of pet wich is really sensible to temperature. It melts at 240 degrees but starts to soften at 70!!! So is is quite dificult no to have a jam. So basically I need to jeep the filament flooding somehow quick to avoid a jam. Right now Im useing a 0.4 noozle and my minimun print speed to avoid a jam is at 60 mm/s with an extrusion with of 0.6 . The problem with this is that some fine details are dificult to get at this speed. So I was thinking: if I get a noozle of for example 0.6 or even a 0.8 mm, will I be able to keep the same extrusion rate but at slower speed? What Im looking for is to reduce speed but mantein flow rate some elevated (the filament has to stay low times in the heat break)
Thanks in advance for the help

I've never heard of anyone having to print at a minimum speed to avoid a jam. Are you using a genuine E3DV6 hot end and cooling it properly with a fan?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Im useing a genuine e3dv5. And yes, it has been confirmed by e3d support that if the hotend is at 250/260 I can perfectly expect that the heatbreak will be at something around 70 degrees, and that would be perfectly "normal" . If you print PLA at 190/200 degrees, the heatbreak will be much cooler of course. But as I said, this particular material behaves like PLA and ABS: it softens at 70 and melts at 240/250 !!! . I have extra cooling in the coldend, actually I have a lot: a big radial fan wich keeps it really cool.

But forget about this, can print, I just need to know if ggetting a bigger noozle would let me keep the same extrusion flow but at lower speeds.
Thanks!

Can you use a more powerful fan so as to keep the heatsink below 70C? I use a 40mm fan and duct to cool my E3Dv6.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

DC42, I preciate your feedback but you are not focuseing on my question. And regarding heatbrak... no, there is no way you can make the heatbreak be below 70 degrees if you print at 260 degrees. My fan is a 120 mm radial fan, way way more powerfull and gives like 100 time more air flow than a 40 mm fan.
And as I said, e3d support has confirmed that 70 degrees on the heatbreak is the expected if the printing temperature is 260.

Edited 1 time(s). Last edit at 05/18/2016 01:04PM by Tinchus.

I'm sorry, but I really think that you are focussing on the wrong problem. It may be normal for an E3Dv5 heatsink to reach 70C if you use the puny 30mm fan that they supply, but with a bigger fan and a duct you should be able to do much better than that.

In answer to your original question: yes I think a larger nozzle would permit a lower print speed.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].