I think I finally got an ABS print of the new nozzle housing.
I used the yellow Inland ABS after some serious de-moisturizing.
Even made the ABS bulkhead.
We can probably get away with just the housing in ABS but I also made the core from ABS just in case.
Printing with ABS is strange.
Dimensionally the print is different from PLA. The ABS cap would not easily thread into the nozzle housing. PLA recommended and fits properly.
The core was not as free-fitting as it is with PLA. Took a lot of sanding but that was easy since it is just a cylinder.
And the 2.8mm hole needed to be cleaned up to get a nice snug fit of the final 42mm PTFE segment.
@TD - FWIW I've been printing with my ABS B2B nozzel for a few weeks. Works great! All parts are ABS. I also made one from 3DS Ekocycle PET. The ABS ones came out a little better, with less cleanup. I really llike your design.
For those of you following this thread...
I've opened up the threads a bit on the B2B nozzle housing to provide a looser fit when printing in ABS.
For the most part, the PLA prints have gone together without much intervention other than truing up some holes or cleaning out the occasional drooping trace.
However, it appears that ABS prints are rougher than PLA prints and this interferes with intended clearances.
Unfortunately, clearance is not something we have a lot of freedom to alter.
To make the ABS housing and ABS core work together (these are the only two that I recommend printing in ABS for ABS printing);
* Clean up the outside barrel of the ABS core to smooth the walls.
* Run a 2.8mm (dia .110") drill through the core and work it a little. Maybe .112" bit would be closer. I want to have the small tube to fit snug in this hole.
* Be sure your 4mm tubing will fit into the core and the tube-nut rests on the core with the properly made tube setup. This shouldn't be too hard to clean up if needed.
* An easy way to clean up the inside of the housing is to wrap sandpaper (180-220 grit) around an hobby knife handle (remove the blade, dummy!) and purposefully smooth the bore of any high spots or offsets.
* Clean out the holes for the core keeper with a jewel's screwdriver or something 2mm in diameter. The keeper is a little tighter also so be sure to test these before you try to fit it during assembly. That's why I put several on a print plate... for when you need another one.
I'm still sucking air on finding good ABS filament. Even the 3D Solutech orange ABS spit a lot of moisture out. You could see it in the cooling tower which exhibited a lot of little holes. When you peel apart the cooling tower, it has the strange likeness to a player piano scroll.
Anyway, below is a print I recommend for the ABS nozzle housings which should yield a free-spinning tube-nut.
I might tweak the core too, but that will have to wait.
I have no proof the core has to be ABS but I believe it to be a good idea for now if you want to use these for ABS printing. At the moment, I've run about 1/2 a pound through a fairly poor ABS print. Really sucks that the 3D Solutech orange was worse than the Inland yellow.
I left the window since it has the little deflection dart that keeps the cartridge from sucking in the de-spooling tube.
Remove the window to load the internal or external spools and replace once the filament is loaded.
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Got some SAE drill sizes you might find helpful:
#34 (.111") for the 2.8mm holes in the hotend core and the bulkhead piece.
#19 (.166") for 4mm tube clearance (hotend tube nut). The nuts should spin freely, but not too free. This hole doubles as a strain relief.
Remember that I am running bowden tubes on the high end of their dimensional tolerance. I need a 2mm ID minimum! That often makes the outside OD closer to 4.1mm.
7/32" for clearing the start/stop chip where the capture ring goes in the hotend tube nut and the cartridge bulkhead.
Clearing this 'blob' avoids the need to orient the split ring.
BTW: I am only running ABS cores, nozzles, and keepers. PLA parts have much greater dimensional accuracy and consistency.
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The making of "ringlets"...
How hard can it be to shave off a few ringlets anyway?
Well, see how steady your hand is in trimming off 1.6-1.8mm of the stock heavy tube.
I could see this working with a regular drill too.
To be sure, accuracy plays no part in the function. Skewed cuts are working just fine.