North90's hot-end

I decided to give this one a try and so far I'm pretty happy with it. Tapping and threading was a bit time consuming but I now have a working hot end with no leaks. Picture is of a Wade's block and is the first decent sized print I did with it.

I used 1/8" aluminum plate for the mounting bracket and just JB welded it.
I used some PTFE tape on the threads of the welding nozzle.
I used an MDF x-carriage for good measure, though the temp isn't too bad on PLA. Haven't tried ABS.
The heater block is the same 1/8" aluminum, just bent around 180*.



Edited 1 time(s). Last edit at 12/10/2011 06:22AM by jkomp316.

Took another pic...

Printing PLA on an unheated bed 25C.

Hi,
Great you gave it a try! And it looks a lot better than the one i made in the pictures i posted
I am working on version number 2 which doesn't need tapping
I made about 10 different hot-ends now and none really failed. The only problem i had so far were some small leaks.
The needle insert is a great improvement, give it a try.
Frank
[www.thingiverse.com]

Edited 2 time(s). Last edit at 12/13/2011 12:04AM by north90ty.

How are your keeping the needle in place and how did you cut it without burring up the edges and ruining the hole?

The needles i used are about 0.8mm outside diameter (22GA), the hole in the copper is 0.6mm. But it is easy to drill in in by hand. They stay in on friction only. (the surface area is so small that the pressure trying to push it out is extremely small: about 1/15 of the pressure at which you push in the filament)

I cut the needles with a dremel cutoff disk, works easy. I debur the edge of the printing side with a file. The hole can easily be opened with a piece of wire (electrical wire).

I already have some needles around from when I dismissed the concept for some reason. I guess I should look into it again. I am about to build a new hotend for a new printer and I'll give it a try.

If they stay in via only friction I wonder if it could make for easier "nozzle" changes, because swapping actual nozzles is not often the easiest thing to do.

I've had good luck with just hammering the nozzle smaller. I think I got the idea from the wildseyed end.

I tried hammering, but i didn't like that you don't know the size it comes out as. I had a smaller needle around that was smaller than the 0.6mm, and secured that one by hammering, which works well.

I don't think that swapping nozzles is a good idea at all, even with commercially bought hot-ends i ended up having leaks after a few changes. The brass that is commonly used is just to soft to be regulary taken apart and put back together.
When you make one of these hot-ends you'll probably end up having plenty of material to build a few. And i that case it is way easier to swap the whole hot-end, or just the insulator+nozzle.

version 2 is on the way: see: [www.reprap.org]