The above is the crib sheet I use for making an extruder. The ingredients are: 18mm PTFE rod (can be whatever), 18mm SS hose clamp, 45mm M6 brass bolt, M6 brass dome nut (can be plated), 4 Ohms of nichrome wire, 100k thermistor, slightly diluted fire cement or fireproof rope cement from the solid fuel supplies house and PTFE "thread seal" tape.
Basically, you make it look like this:
I'll add pertinent details as people ask awkward questions. Or I sell them for NZ$55 and ship worldwide :)
The main issue people have with PLA extruders is that they leak where the brass barrel screws in to the PLA. There are many complex machining options, but the easiest is to wrap the barrel with PTFE tape, screw it in, and then add a heavy stainless steel hose clamp over the join. That holds it!
I notice that you have the heated zone distant from the extruder nozzle. Is it better to have an extended melt zone and do you not have problems with PTFE softening?
ReplyDeleteFortunately the brass barrel and nozzle are excellent conductors and we get away with it.
ReplyDeleteThe PTFE does not soften enough to allow the nozzle to move, but it will leak unless you use the hose clamp.
thanks for the tip. I am trying to perfect my hotend but the sheer number of variables makes it difficult... it would be a lot more difficult without blogs like yours though, thanks! if you are interested in our build we have some of it logged at www.metas.cc. Always good to see kiwis pushing reprap development!!
ReplyDeleteWow Vik those notes look like they are from 2006-2007?
ReplyDeleteWhy muck with a good design that works?
ReplyDelete