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Hi Gang,
I am needing to replace the inner tube in the hotend. I have recently replaced the nozzle on the hotend (with the fancy new one) .5. However, have to replace the inner teflon tube. I have been unable to find the cross sectional drawing of the hotend. Could any of you guys suggest the sizes I may need or where I might find the drawing.... I know I have seen it on the wiki somewhere... But have been unable to trace my footsteps to find it... I should probably replace both the inner and outer tubes... I am having problems with the ez struder digging into the filament. When I manually retract the filament the end appears thick... Guess that over time the teflon tube stretched.. Funny never had that problem with the old extruder... Guess that's the price you pay for progress
Cheers,
Don S
Ps any of you had a chance to compare Simplify 3D to Kisslicer.. I am reluctant to shell out the $140 Bucks before I get some solid opinions... Bye D

noddynomolos wrote:Hi Gang,
I am needing to replace the inner tube in the hotend. I have recently replaced the nozzle on the hotend (with the fancy new one) .5. However, have to replace the inner teflon tube. I have been unable to find the cross sectional drawing of the hotend. Could any of you guys suggest the sizes I may need or where I might find the drawing.... I know I have seen it on the wiki somewhere... But have been unable to trace my footsteps to find it... I should probably replace both the inner and outer tubes... I am having problems with the ez struder digging into the filament. When I manually retract the filament the end appears thick... Guess that over time the teflon tube stretched.. Funny never had that problem with the old extruder... Guess that's the price you pay for progress
Cheers,
Don S
Ps any of you had a chance to compare Simplify 3D to Kisslicer.. I am reluctant to shell out the $140 Bucks before I get some solid opinions... Bye D

See this link for a cross section: http://forum.seemecnc.com/viewtopic.php?f=54&t=2254

Cheers Eaglezsoars!!
DO you know what the new length of the PTFE tube should be cut too? the new nozzle seams to be slightly shallower? Any suggestions would be greatly appreciated..
Don S.

noddynomolos wrote:Cheers Eaglezsoars!!
DO you know what the new length of the PTFE tube should be cut too? the new nozzle seams to be slightly shallower? Any suggestions would be greatly appreciated..
Don S.

I am sorry but I do not know what the proper length should be. Could you send an email to [email protected] and ask them the same question?
Perhaps another user knows the answer to the question and would be kind enough to answer.

I had to take apart the hotend from my Orion and the tube from the newest type of Seemecnc hotend is 45.10mm long. There is only the one tube.

I am having issues with this little ptfe/teflon part as well, it looked like it had been a 6mm OD rode that had been turned down to make a small insert area inside in the brass nozzle. Is it possible to just replace the whole thing with a brass tube that is 45 MM? I can try to get some pics if need be.

TFMike wrote:I am having issues with this little ptfe/teflon part as well, it looked like it had been a 6mm OD rode that had been turned down to make a small insert area inside in the brass nozzle. Is it possible to just replace the whole thing with a brass tube that is 45 MM? I can try to get some pics if need be.

Yours apparently had two PTFE tubes. The one on the inside was 4mm OD and 2mm ID on the outside of that was another tube that was slit so it
would fit over the 4mm tube. It was 6mm OD and 4mm ID. The latest hotends use just the 4mm tube and it is 45.1mm on my Orion.
I don't know about using a brass tube, why not what is supposed to be in there, a PTFE tube.

Eaglezsoar wrote: I don't know about using a brass tube, why not what is supposed to be in there, a PTFE tube.

Because I don't see one for sale on the seemecnc site and I can't source one here locally and I need a quick fix.

A brass tube won't work for PLA, the reason that hotends started to use a PTFE liner is because in the transition zone PLA likes to grip the sides of the inside of the hotend, then expand to fill the tube "jamming" the hotend. Newer hotends are moving to stainless heat breaks, but if you look at the latest developments in say the E3D V6, the stainless bits are getting shorter and the PTFE longer to reduce issues with PLA.

The reprap Wiki will give you a good overview of how modern hotends evolved, there are several hotends that used PTFE instead of PEEK, but it's not structurally sound at printing temperatures, so people started using PEEK for the structural part and PTFE just for it's inate low friction.

Polygonhell wrote:A brass tube won't work for PLA, the reason that hotends started to use a PTFE liner is because in the transition zone PLA likes to grip the sides of the inside of the hotend, then expand to fill the tube "jamming" the hotend. Newer hotends are moving to stainless heat breaks, but if you look at the latest developments in say the E3D V6, the stainless bits are getting shorter and the PTFE longer to reduce issues with PLA.

The reprap Wiki will give you a good overview of how modern hotends evolved, there are several hotends that used PTFE instead of PEEK, but it's not structurally sound at printing temperatures, so people started using PEEK for the structural part and PTFE just for it's inate low friction.

Thank you for your explanation on why a brass tube won't work.

Polygonhell wrote:A brass tube won't work for PLA, the reason that hotends started to use a PTFE liner is because in the transition zone PLA likes to grip the sides of the inside of the hotend, then expand to fill the tube "jamming" the hotend. Newer hotends are moving to stainless heat breaks, but if you look at the latest developments in say the E3D V6, the stainless bits are getting shorter and the PTFE longer to reduce issues with PLA.

The reprap Wiki will give you a good overview of how modern hotends evolved, there are several hotends that used PTFE instead of PEEK, but it's not structurally sound at printing temperatures, so people started using PEEK for the structural part and PTFE just for it's inate low friction.

I'm printing ABS though, no PLA for me and I just need a band-aid for a few days until my shipment arrives. My ptfe liner got mangled somehow and then I found out it was actually two piece of tubing, one stuffed inside the other...

You MIGHT get away with it for ABS, it doesn't behave the same way as PLA in the transition area.