A Bit of Background
This HotEnd was developed after struggling with the fact that in Argentina (were I live) PEEK is very hard to come by, very expensive and a controlled material (since it can be used to manufacture guns).
Therefore, I went and designed a PEEK-free HotEnd.
Since PTFE is available and fairly cheap, I started to work on building a HotEnd based on that insulation.
PTFE is easy to work with but the threads don't last long and are quite fragile. To solve this I went on and designed a "contained" PTFE insulation.
I took some ideas from the Budaschnozzle (which I tried, unsuccessfully, to build replacing PEEK with PTFE)
I'm a Hobbyist Lathe operator, so a lot is done on my lathe. That's a lot of help and makes this cheap.
I've used this HotEnd for at least 3 months now, and around 13 Kg of filament have gone through it. Normally I print with 0.5 mm nozzles at 40 mm/sec and at 230 - 245 ºC.
I Hope some people out there find it useful.
Gustavo "Crispy" Blanco
The Crispy HotEnd
Watch it in action
The HotEnd Disassembled
BOM (Build of Materials)
- 1 * 50 mm Long 12mm Aluminium Round Bar (Barrel)
- 1 * 20 mm Long 12mm Brass Hexagonal Bar (Nozzle)
- 1 * 12 mm Long 12mm PTFE Round Bar (Inner Insulator)
- 1 * 25 mm Long 1" or 25mm PTFE Round Bar (Outer Insulator)
- 1 * 25 mm Long 1" or 25mm Aluminum Pipe (Shield)
- 2 * M8 Large Washers
- 2 * Pieces of MDF 5.5mm thick (use the large Washers as a template)
- 1 * M8 Nut
- 1 * 6mm x 32mm x 80mm Aluminium square bar
- 3 * 1/8" x 50mm Bolts
- 3 * 1/8" nuts
- 2 * M5 grub screw
Tipically I start with the Barrel.
It's a 50mm long 12mm Aluminum round bar which it turn to 8mm in diameter for 45mm, and make those 45 mm a 8x1.25 Thread.
Next, I take a piece of 1" (or 25mm) Aluminum Pipe and cut a 25mm long section.
On the Lathe and with a piece o 25mm PTFE, turn it so you can fill the pipe (try to get it tight).
With a 6.75mm Drill bit, drill the PTFE (at least 30mm deep)
Then with a 12mm Drill bit, drill 18mm into the PTFE.
Tap the remainder of the 6.75mm hole (8x1.25 thread)
Now take the 12mm PTFE and brill a 3.2mm hole, drill it all the way.
Crispy HotEnd v1.5
After receiving a few suggestions in Argentina's RepRap Forum, I decided to take the time to make the following changes and all the tests show better performance.
First, replaced the film resistors with Ceramic Heater Cartridges.
Second, Drilled a 12mm hole, 7mm deep into the heater block. This allowed the Nozzle to screw into the block, keeping it closer, compact and reduced the total height of the Hot End in 7mm
Third, Drilled a 2mm through hole for the Thermistor.
Heater Cartridge in place. To fit it snugly wrap it in aluminium foil (if required)