HOW TO GET A CHEAP ALL-METAL-HOTEND TO WORK!
First you have to understand how the hotend is supposed to operate. Basically the filament needs to be solid right up until it gets to the nozzle. The Nozzle flash heats the plastic to above its melting point and squirts onto the print. The hotend is the nozzle and the heat break is cooled by the heat sink. In the original PTFE type of hotend this isn’t much of an issue because Teflon is partly an insulator and a very low friction surface. With the all metal design the PTFE stays well away from the nozzle and the filament leaves its protection way before it gets to the nozzle. So how can this work? Everything must stay cool right up until the nozzle by dynamic removal of heat, especially from the heat break.
With expensive hotends the machining is so good the contact the heat-break has with the cooling block is very efficient but the cheap products aren’t so good. Check out “https://tiny-machines-3d.myshopify.com/pages/instructions”. The trick is to effectively cool the heat-break while having it sealed against the nozzle. This is difficult with cheap hot ends because the contact at the nozzle end can be much better than the cool end. The answer is thermal paste at the cool end of the heat-break and the heat-break pushed firmly into the heat-sink, secured well with as many grub-screws as possible. If melted plastic gets as high as the heat-sink its a jam. Not only this but the filament material will not slide well in the heat-break, if it’s molten.
Last but not least, retraction distance is critical. Retraction pulls the molten material back and to find the ideal you may suffer a lot of blockages. It’s best not to exceed a couple of millimetres. This may give you some stringing but save a whole lot of work clearing the extruder.
There is not perfect hotend because the diameter of the your filament will always vary and that effects how the filament moves through the extruder. You can only lubricated the cool areas in an all-metal extruder, so you can only try to keep as much of the path to the nozzle as cool as you can.
I hope this rant will help those that read it. It’s not original but another explanation of how you can get away with using a cheap all-metal hotend.
Hello all. I'm setting up my new CR10 and i'm asking the group, what is your preferred method of part/plate adhesion? I'd like to try and keep the glass plate as clean as possible while still getting parts to stick in place. I've read about hair spray and PEI sheets so I'm looking for input from the group as to what is the most common method. I've had good success with my Ender 3 but the glass plate is pretty awful looking what with glue sticks and Gloop at different times. Thanks all.
Thanks everyone for all the input. I found a mirror big enough for the S5 and its on the way. Going to read up on the sugar method and try it. Clean up on a 20" mirror is a chore by itself. Sugar would make it simple.
Hi still learning but am running a Creality Cr-10 in a fume hood (think a ventilated enclosure). I'm trying to get PETG to cooperate. I am still struggling with bed adhesion to a certain extent but the bigger issue I'm running into is I think warping. I've included a couple pictures of the last print I did its a Megalodon tooth thats scaled up to 7 inches (the size of the largest ones found) Some of the roughness at the edges is from where I've partially cleaned away the supports. I'm using cura slicer and the Amazon basics black PETG. nozzle temp for this was 240 bed was 50 print speed was 45mm/s. If any other info would help with troubleshooting let me know and I'll update accordingly