Due to the cold evenings it's been hard to get work done, but it was mild last night and I managed to make a new Hot-End to go with my WADE Geared Extruder, it's loosly based on Adrian's new Hot-End -http://reprap.org/wiki/Geared_extruder_nozzle
I first had a go at some heater blocks. -
On the left was an attempt to make a Clamp version, but it was a bit big and didn't clamp very well around due to the mass of Brass and the short cut slot.
In the middle was just about right, but I over-drilled the hole so tapping was not going to be good, but it was a easy part to make in the drill press and using HEX brass stock, note the small hole for the thermistor.
On the right is the Brass screws I'm going to try to make into a hot-end, normal M6 thread, and it has a nice ready-made centre point in the head.
Clamped in Vice with M6 Nuts to stop the body from getting squished.
It worked ok but the 0.5mm extruder hole ended up being 0.55mm, not a big problem, but I would not recommend doing this yourself if you don't have decent equipment, it's one good thing to buy a well made one.
Now for some support materials-
PTFE Rod 16.57mm (Ebay £0.99p for 165mm x 16mm)
PEEK Rod 14mm (Ebay £2.20 for 400mm x 16mm)
Off the shelf 16mm Aluminimum Clamp as used on my previous Pinch Extruder. (£1.50)
Clamped in Vice with level support under the PEEK then drilled with a Woodworking drill bit on the Drill press.
Repeat with the other holes in the PEEK (My spacing is to match the Aluminium clamp, and they are not the same as the mounting holes on the WADE extruder)
PTFE drilled with a 3.2mm hole and tapered (filed and sanded) to make a snug-fit into the bottom of the Extruder.
Remeber to dish the PTFE enrty hole so the filament can fint it's way into the hot-end easily.
And you need to Drill and tap (M6) a small way (I did 5mm) into the PFTE for the heater barrell, you don't need it to go a long way into the PTFE as the PEEK is doing all the support and most of the heat-sinking.
I need to make another heater block but this is about all you need.
The Aluminum clamp provides support for the PEEK and aids to mechanical fixing to the Extruder and also constrains the PTFE . It also should help with Heat-sinking.
I still don't have my Power Resistors yet; they should be here tomorrow, so with a bit of luck I can test this new Geared Extruder and Hot-End at the weekend.
I also need some longer M4 Bolts...