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 -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...

RichRap



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.

RichRap

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.

RichRap

WADE Extruder parts printed - And My UP! Bearing finished

They all printed well, just a very small warp in the big part, and it messed up the last top layer for some reason?

The big Cog is perfectly flat, I can't really understand why, I was expecting major warp on that.

I am using 2 layers of Kapton tape at 90degrees, I think it's making my prints stick-down better.

I now need to make the hobbed bolt and assemble it then re-calibrate my whole machine again.

I have also started on a Heated build-bed so as soon as I get both working I can start to print my parts for mendel.

I also forgot to mention that I re-started my UP! Bearing print (by hacking the first 27 layers out of the GCode), it finished and the bearing worked !  I'm still amazed that it all fused together especially after a long gap between printing the first half and the second.

See the blue line -

And it rotated 180 degrees.

This is full-size, I did try a another at 50% size but that didn't work very well.

It's printing the Stanford Bunny at the moment to celebrate getting my extruder parts made.
- Bunny - http://www.thingiverse.com/thing:3731 -check it out, a great model.

RichRap

Printing Upgrades - Progress update

I have not had much time to print or experiment with my Repstrap in the last week, but it has been hard at work printing my first Geared Extruder parts so it can start to upgrade itself.

Tweaking and tuning for better Quality has been very worthwhile, it teaches you lots about Fused-filament limits and also about you'r specific system, you can't learn everything from a Wiki, Forum or Blogs, the best method is try it yourself.

For now I have settled on the following settings so I can start to print out some practical upgrade parts.

This is not the best quality, but I'm getting minimal warp and speed is not bad - 

A print speed of 1000mm / min

0.4 layer height

0.5 Nozzle size (but I'm going to make and test a 0.7 shortly)

One outer shell (2 shells when printing gears)

1.5mm Infill pattern (45 and -45)

Outline at 90% speed.

Basic Pinch-wheel Extruder (That I'm very impressed with actually)

Still not using accelerations in my firmware, but as soon as I have a working Geared extruder, then I'm going to re-tune the whole system again and switch Accelerations back on to try getting the speed up.

Print 1 on the far left was the very first thing my machine printed.

Print 2 was 1.8mm infill and slow, ok quality, but not correct Extruder settings.

Print 3 was much too fast. Good extruder settings, but the motor was skipping steps (you can see loops of infill at the front).

Print 4 has just completed, 1000mm/min 1 outline and 1.5mm Infill, nice and smooth, and feels strong.

I printed a few other things, to test some of the earlier settings - 

Whistle - (Version 2) - http://www.thingiverse.com/thing:1046

Probe Holder - (only 50% printed, I decided I didn't need one that badly) - http://www.thingiverse.com/thing:3525

It's printing the Geared Extruder Block and both the WADE gears Now, so I will hopefully be able to Blog them tomorrow.

RichRap.

How I made my Basic Extruder -

I Just thought  I would put up a few photos showing my first basic extruder, it's working very well and I have used off-the shelf Aluminium 16mm clamps -

You can get these from many places for just a few pounds each (£1.50, $2, 2Euro).

These both hold it to my Repstrap frame and also constrain the PEEK/PTFE hot-end.

It also has the added advantage of cooling the hot-end PEEK, so less of the heat travels up towards the extruder - all good things.

It's just a basic Pinch at the moment, I plan to print a Geared Extruder over the next few days and use the same 16mm Aluminium mounts on that.

RichRap.

Warp Factor 9! - Printing the PP3DP (UP!) Bearing on My Repstrap

So maybe a bit over ambitious for a Repstrap with no Heated bed but I had a go anyway.

I really like the UP! Bearing - get it here - http://www.thingiverse.com/thing:3981

Not a bad start - Poor choice of infill size - too many start-stop operations

Starting to warp on the front edge - Note my use of double sided tape! in a poor attempt to counter the warp.

At this point the warp was going to destroy my extruder, so I reluctantly had to turn it off. You can see the bottom front edge getting more and more melted after each pass.

It would have taken about 2 hours 20mins to print in total, which is almost exactly twice as long as on the Up! Printer, I expect it could have be much faster as I had it set on 2 x Shells and a slow outline speed. it was also resetting to origin after every layer.

All the bearings are clear and I think would have moved and worked if I could have printed it all.


If anyone has a Mendel with a heated bed, I would love to see if this could be printed and if it worked afterwards. - Let me know...


If you want to try - You will need a support structure;  -
I made a 1.7mm high ring positioned under the balls to get them to the correct height in the bearing. For me the balls started to print after layer 4. The ring needs to be 58mm outer and 46mm inner. - Good Luck !


I really need to stop messing about and print some upgrades for my extruder, but it was lots of fun trying to print this.

I really want a heated build-bed now...

RichRap.