Excalibur Hotend

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Excalibur Hotend

Release status: Experimental

OrganPipeHotend.jpg
Description
full metal hot end with cooling fan
License
unknown
Author
Contributors
Based-on
Categories
CAD Models
External Link


Introduction

The Excalibur Hotend derives from its precessor, the Organ Pipe Hotend.

The main difference between the Excalibur Hotend and the Organ Pipe Hotend is that is has no single pipe anymore. Instead it has a barrel and a separate nozzle.

Barrel and nozzle can be exchanged very rapidly, allowing swift changes of material types (e.g. from ABS to PLA) without having to clean the barrel each time.

Excalibur Hotends and Organ Pipe Hotends are compatible. That means that if you already have an Organ Pipe Hotend, you only need to make the barrel and nozzle.

The Excalibur Hotend can be made without any lathe. A drill press will do.

OrganPipeHotend1.jpg

OrganPipeHotend2.jpg

The Pipe

The pipe consists of the following parts:

Quantity Description Specifications
1 tube stainless steel, Length: 60 mm, OD: 4 mm, ID: 3.3 mm
1 hex screw brass, M6 x 8mm


OrganPipeHotend18.jpg

Tools you need:

- Drill press

- Blowtorch

- Soldering paste

- 0.5 mm PCB drill with mini chuck

- 4.1 mm metal drill

- center drill (optional)

- nozzle sharpening tool

- drill press vice

OrganPipeHotend17.jpg

Drill a 3.3 mm hole into the shaft of the screw 11 mm deep (if the screw is 12 mm long). Next drill a 4.1 mm hole 5 mm deep into the first hole. A center drill might be helpful. It is a good idea not to put the drill but the screw into the chuck of the drill press.

Now use the nozzle sharpening tool to taper the head of the screw. Just put the screw into the chuck of the drill press and sink it down into the center of the tool.

Duesenfraese.jpg IMG117.jpg

(The two black parts are cylindrical milling cutters. They do not rotate.)

Drill a 0.5 mm hole into the tip of the screw head. Usually I do this by putting the screw into the chuck of my drill press and place a 0.5 mm PCB drill under the tip. For holding the drill I use a mini chuck which I bought at a watchmakers supply shop. The chuck has a shaft which I fixate in a small vice. I use approx. 600 rpm when drilling the hole.

Now your nozzle is ready.

Now you have to solder the parts together. I use a small blowtorch and some soldering paste for that. At 610°C the solder melts. It isn't difficult at all. But be careful not to burn yourself. I drilled a 4.1 mm hole into an aluminium cube and put the cube into a vice when soldering. The hole holds the stainless steel tube.

It is a good idea to make more than one pipe as you may want to change between different nozzle diameters or types of material.

The Cooling Bar

OrganPipeHotend4.jpg

The cooling bar consists of two parts:

Quantity Description Specifications
1 square profile aluminium, 10 x 10 x 58 mm
1 threaded rod brass, Length: 40 mm, M6

Here you see a cut through the cooling bar.

OrganPipeHotend5.jpg

Later the bar will hold the pipe which is just clamped into the "chuck" allowing very rapid changes of pipes.

OrganPipeHotend6.jpg

Tools you need:

- Drill press

- 8 mm metal drill

- 5 mm metal drill

- 3.2 mm metal drill

- long 4.1 mm metal drill

- center drill (optional)

- drill press vice

- hacksaw

- M6 tap

At first drill a 3.2 mm hole through the M6 threaded rod. Again put the rod into the chuck of the drill press for this and put the drill in a vice below. A center drill might be helpful.

Next drill a 4.1 mm hole at length through the square profile.

OrganPipeHotend7.jpg

At 25 mm from the bottom up drill a 8 mm hole in horizontal direction.

OrganPipeHotend8.jpg

Now take a hacksaw and saw a slit from the bottom to the 8 mm hole. This will be your "chuck" holding the pipe.

OrganPipeHotend9.jpg

Drill a 5 mm hole from the top 8 mm deep. With a tap cut a M6 thread into it.

OrganPipeHotend10.jpg

At last screw the threaded rod into the square profile. Glue them together later after you made sure the pipe aligns well. I use UHU Endfest 300 for it, but JB Weld might do as well.

OrganPipeHotend4.jpg

The Heater Block

For the heater block you need:

Quantity Description Specifications
1 cube aluminium, 20 x 20 x 8 mm

Tools you need:

- Drill press

- 5.2 mm metal drill

- 5 mm metal drill

- 2.5 mm metal drill

- center drill (optional)

- drill press vice

- M6 tap


OrganPipeHotend11.jpg

Here is a cut through the block:


OrganPipeHotend12.jpg

The Cooling Plates

The cooling plates consist of the following parts:

Quantity Description Specifications
1 plate aluminium, 60 x 40 x 3 mm
1 plate aluminium, 20 x 40 x 3 mm
8 screw M3
8 nut M3

Tools you need:

- Drill press

- 3 mm metal drill

OrganPipeHotend13.jpg

The Fan

Use a 40 x 40 mm fan 12V.

How to exchange the Pipe

OrganPipeHotend14.jpg

1. Losen the two red marked screws.

2. Screw the pipe down through the heater block.

3. Pull the pipe down

Now you have removed the pipe. Install another one by reversing the steps.

Sources

- solder paste from Bengs Modellbau: http://www.bengs-modellbau.de/werkzeug/loetzubehoer/silberlotpaste.php

- stainless steel tubes from Ebay: http://www.ebay.de/itm/ws/eBayISAPI.dll?ViewItem&item=221146411608