Thursday 28 October 2010

Making a new Extruder Nozzle Hot-End - DIY - using basic tools only

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 -
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...


Friday 15 October 2010

New Extruder build and hobbed bolt experiments

I still have not had a chance to test my new heated bed as my extruder has been in bits for the last week.

I have been trying to make a Hobbed bolt - It's not as easy as it looks on Youtube!

My first rig used the extruder and a failed print to mount the bearings and the bolt -
Not very good, didn't turn very well.

That seems to work much better.
Hopefully that will be good enough?

When it's assembled it seems to push well, so I just need to mount the motor and work out how to strap it onto my repstrap - then completly change all my firmware again this weekend.


Saturday 9 October 2010

First DIY Heated-Bed build.

I had some parts on order for a Heated bed - Both the Alu Clad resistors and the Aluminium was quoted as two weeks delivery, so I used a rather scratched bit I already had to test a Heated bed.

MDF base, then a layer of Aluminium Foil (not shown)
Opal Polycarbonate 3mm sheet.
Silicone baking sheet (240 deg rated)
Then 3mm Aluminium sheet.

And because of not having my Resistors, I didn't want to use Nichrome Wire, so I went for a quick and dirty method others seem to have had some success with...

A brand new Iron for just £3.84 (1/4 the price of my resistor order) - It was also a good plan getting the cheapest Iron, as this just had a very thin Stainless sheet over a nice cast Aluminium base, and it was very small and Light -
So Rip-off the Stainless sheet, and remove the red silicone blob.

It has 3 mounting points already, they just need to be drilled through.
Sand the base with fine wet and dry.
Add a fine layer of heatsink compound and fix to Aluminium plate.
Wire it up and isolate.

Assembled and a glass hot-plate (£1.50) on top, this should be good for PLA (not tested yet).

For PLA It's getting 55 deg C-in the middle and about 50 deg C around the edges, may need a little more tweaking.

Without the glass and at maximum power I can get it up to 130deg C (120 edge) so it should just about be ok for ABS? - Hopefully I can test it tomorrow.

The MDF only gets slightly warm so it seems to be a reasonable use of materials, I would have liked to use PTFE Sheet, but maybe on the next one.

The very next day my Aluminium order turned up, so at least I can build a really nice one for the next machine...

Still waiting for my resistors to get here, but I'm really happy with the Iron for now.