KHAT - Kossel Hotend Attachment Tool

Last crawled date: 4 years, 3 months ago

KHAT
Kossel Hotend Attachment ToolAssembly Video - Youtube
The 'Kossel Hotend Attachment Tool' is powerful interchangeable setup designed to make swapping hotends a quick task. This tools works with the Aluminum Fisheye Effector. With this setup, you can have multiple hotend assemblies ready to swap out with ease! No more changing nozzles all the time, when you can just have multiple assemblies to swap out!
Bill Of Materials

1x - M3 Single Print head aluminum fisheye effector (if not owned already)eBay


1x - Molex Micro-Fit 3.0 Dual Row (8 Circuits) Male & Female Receptacle PlugAmazon or eBay


2x - M3 x 6mm x 5mm Brass Knurled Nuts
4x - M2 x 4mm x 3.5mm Brass Knurled NutsAmazon Kit


2x - M3 x 10mm Hex Socket Head Screws
2x - M2 x 4mm Hex Socket Head Screws
2x - M2 x 12mm Hex Socket Head ScrewsAmazon Kit


1x - 4010 blower fan - 12vAmazon or eBay

1x - E3D v6 Clone Kit (with 30mm fan, heatblock, heatsink, thermistor, heater)Amazon - Better kit or eBay - 2nd Amazon option
Optional stuff to make it pretty:
Shrink Tubing - Amazon
Zip Ties - Amazon
If you need parts individually for the connectors, the Molex numbers are:
Molex 43025-0800 Female connector
Molex 43020-0801 Male connector
Molex 43031-0001 Male Terminal Pin
Molex 43030-0001 Female Terminal Pin
Printing

Print the khat_left.stl and khat_right.stl files together.
0.2mm layer height, 20% infill with supports.

Print the khat_cooler.stl by itself.
0.2mm layer height, 20% infill without supports.
Assembly
Brass Knurl Nut Installation

Using any soldering iron, heat up and press in the brass knurl nuts into the printed parts. The smaller M2 brass knurl nuts will press into the fan holes, on the outside (standoff side), and the top internal holes. These will be used for the 40mm and 30mm fans.

The two larger M3 brass knurl nuts press into the top ring, to be used to attach to the aluminum effector.
Hotend Installation

Put the assembled E3D v6 Hotend into the assembly.
You'll want to make double sure you've installed the nozzle into the heatblock correctly!! (Look up '3D printing guides - Assembling the E3D v6 hotend' by Thomas Sanladerer)

Once you've got the E3D v6 hotend installed, align it so the nozzle is closer to the side with the standoffs for the 40mm fan (see picture). Snap the two sides together and move on to the fan install.
Fan Installation

The larger fan (40mm) installs to the outside of the assembly with the blower opening facing downward. Use 2x M2 4mm to 6mm screws to attach to the face. The wiring should run along the side with the smaller fan.

Install the smaller fan (30mm) fan into the cove of the assembly. You'll want the wiring facing up, running out of the notch cut for it. Use 2x M2 12mm screws on the top to affix it to the assembly.
Wiring Warning
The wiring is probably the most time consuming and tedious part of this whole build. TAKE YOUR TIME AND DO IT RIGHT!!! I'm not even kidding. I messed this up a couple times and have never been more frustrated! If you don't get the crimps correct, your wires will pull out, come loose, or worse. I'm not even joking, unless you have a pin removal tool for these, a placed or botched pin will ruin the entire connector.
The official Molex crimp tool is stupid crazy expensive (like $300+). Not paying that. I was able to crimp the Molex Micro-fit 3.0 pins using a SN-28B Dupont Crimper, being very careful to not crimp past the wire folds. Cheaper, does about the same job.
You'll only need one female plug, which runs back into whatever mainboard you have. Though, it doesn't hurt to order the pack that comes with male and female, just to have some extras on hand.
Plan out how you'll have your wires, a pattern easy for you to remember and replicate.
You'll need to reuse the same formation when building more of these.
Wiring
Run all your wires together on the corner of the small and large fan.
Zip tie them together here, as a base point.
Leave about 80mm (3 inches) of wire from the top of the assembly. Cut the excess.
Strip back the wires the same length in preparation for crimping.
Using the SN-28B crimper, crimp just the two sets of flaps meant for the wire.
DO NOT CRIMP THE PIN LOCKING NOTCHES!
Verify all your crimps are good. For real, this is your last chance.
Insert pins into connector in whatever pattern you decided on.
To Do
Add bed leveling attachments.
Make a video detailing assembly (especially the pin crimps).
Change Log
Jan 12, 2020 - Added assembly video on Youtube
Jan 15, 2020 - Updated links, some sellers were sold out