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Post by ratmonkey on Oct 31, 2013 6:48:37 GMT -5
If there is the need of ptfe in the hotend, then the big one must be used. The thinner one is ONLY for insulation of heater/thermistor leads. The big PTFE-tube should have an OD of 4mm or more. If the upper id of the hotend is not even close to this, then you do not need a PTFE-tube in the hotend.
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Post by willoftw on Oct 31, 2013 11:06:39 GMT -5
Ahh okay, that makes my life easier, ill take some more detailed pictures tonight, i hopefully will have some plastic to test it aswell!
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Post by willoftw on Nov 4, 2013 15:33:35 GMT -5
Hey guys, just a quick update on this hot end. I managed to have it working, a little bit. if i feed the filament though manually WITHOUT the fan at ~250 it works fine, but as soon as i stop feed it jams, my small non-3d-printing brain is telling me this is because the aluminium serrated tubing is getting too hot. So i plug the fan in, but then the end never seem to get hot enough to melt the filament. Do i just need to regulate the fan speed? the hot end seems to be getting its hottest at the base of the serrated tubing, NOT the aluminium block. which doesnt seem correct to me, but hey what do i know? any help would be appreciated. pics! Red laser show point its getting hottest (its a laser thermometer) Peace
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Post by ratmonkey on Nov 5, 2013 2:38:59 GMT -5
What type of filament do you use? ABS or PLA? 250°C would be too much for PLA, but ok for ABS.
The jamming can happen, if the upper part of the hotend is getting to hot. The filament swells when it gets hot. If the lenght of swelling is too long, then you have too much friction and it starts jamming.
The hottest part should be the heaterblock. Have you controlled the Temp in Repetier-host?
What thermistor-type did you set in your firmware?
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Post by willoftw on Nov 5, 2013 6:27:22 GMT -5
Using PLA, without the fan it works at 200, although my laser thermometer is only reading ~70 ->80. The heater block defiantly isn't the hottest, its seems to be the base of the heat sink that gets hottest!
I was using ponterface for Mac when setting and monitoring temp.
Using thermistor 1. But I don't really know if that's correct, iv asked or Richard for some info but no dice.
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Post by ratmonkey on Nov 5, 2013 9:31:55 GMT -5
If you use marlin, then it should be thermistor type "7". That one from honeywell. Ok, 250°C is definitely too much for PLA. I print it at 190°C. The first layer at 200°C.
At 250°C and without the fan, the PLA will swell too much the way up in the hotend and will jam. Lower your temp to 190-210°C an try it again with the fan. All-metall-hotends are sometimes a bit tricky with PLA because of the higher friction of almost molten PLA.
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Post by willoftw on Nov 5, 2013 10:01:25 GMT -5
Ahh okay, changing the thermistor type may well be causing the issues for me. As it will probably be reporting an incorrect temperature. Un fortunately the USB snapped off my RUMBA control board :Z so I've ordered a ramps 1.4 Instead. Hopefully it will arrive this week and I can get printing!
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Post by tomguest on Nov 16, 2013 13:56:32 GMT -5
I wrap the block to stop the fan cooling it as well as the heatsink.
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