Originally shared by Joe Spanier
I’ve had loads of issues with my hotend since I went to 1.75. Its come down to after my filament sits in the hot end for a bit it completely seizes forward movement. I can’t even force it through with pliers.
The hotend is 45mm of 1/4-20 brass threaded rod. Bored to 2mm with an aluminum heatblock for a 40w heater core.
The rod threads into a 70mm long aluminium block that’s 1x.5" and has heat fins cut into it with a 40mm fan bolted to it.
There’s no gap between the pneumatic fitting and rod.
I get some prints that start but it seizes up about hallway through the second stack of cubes in the 5mm calibration cube print from triffinhunters guide.
Same results in abs and pla from 2 different vendors.
Any or advise would be great
You don’t have any PTFE liner? Aluminum and brass conduct heat very well, too well for a all-metal hot end. The heat is rising up, getting too cool, and causing a plug. It’s likely that your hot end design simply just sucks and hasn’t taken into account the plethora of things that as a community, we’ve already tried.
Do you have any drawings of the hot end design, or pictures? The E3D hot end is all metal, and went through many revisions just to get PLA to work properly. I wouldn’t dare try making your own without some experience under your belt.
It sounds like a clog also. I have experienced a few of them and they dont make any sense, try cleaning the nozzle completely with acetone and a lighter, it sounds dangerous and it can be if you dont watch yourself, make the nozzle that you can see the hole if held up to a light.
Going from a 3.2mm bore to a 2mm essentially doubled the heat creep towards the extruder, which means that the temperature at the top of your hotend has doubled as well. So there’s a good chance that your hotend is just not up to the task and forms a plug, as @ThantiK suggested.
You’re saying you can’t force it through with pliers - can you pull it out with pliers?
@ThantiK dont pull punch’s do you
You guys are right. A plug is forming at the top and what your saying is what I suspected. I had done this design in stainless with 3mm and no issues but had lots of issues drilling the stainless for the 2mm.
I am going to try adding a PTFE sleeve and see if that helps. Or if going to just mild steel helps.
I can pull it out fine. Just won’t push in. Weird thing is if I push it back in it melts fine and goes on with its day until the next plug
Incredible, only in an open source community would you have such a fast response. Good to know guys because I wanted to start making my own hotends for hobby then eventually sell.
Good luck. If you dont have a good CNC lathe and a tooling hook up I would just stick to buying them. Ive gone through enough time and tooling to buy 3 e3ds
If you master deep hole micro drilling on any sort of a small lathe I wanna hear your secret
Yeah, the drilling was the hardest part in my trials as a well. I used 1.4301 as that was what I had at hand and bored of out with a simple 3mm HSS drill and it took me about half an hour to make it through, using lots of oil and going really slow - as you get a feel for what the drill can handle, you’ll manage to go a lot faster. The next ones I made took less than five minutes, with the drill perfectly intact. I then used a reamer to get the bore smooth and finished it up with some aggressive polish. But still, I ended up buying an E3D because I was getting tired of my sketchy hotends failing or not working as expected. Never regretted it.
You used a 3mm drill for 1.75 filament?
I’m probably going to order a pair of e3d’s next week.
I use 3mm filament, for which 3.2mm is the de facto standard bore.
Ok yea. Ita frustrating because the hotend I did for 3mm with the same design worked perfect. Even pla. I’ve tried SS now too at 1.75 with the same issues. But I reamed the 3mm and I dont have a 2mm reamer so I think that has something to do with it as well.
For anyone who cares I gave up on this venture and ordered and e3dv5 from http://filastruder.com. All I can say is wow shaky a difference. The thing is just pretty and works great. I’ll get some pics tomorrow.