This page provides some additional information about eliminating stringing. If you haven’t done so yet you should read this blog page to get the necessary background information.
This page describes what happened after I changed the hot end/nozzle assembly on my printer. After I posted the the original page on stringing I got some feedback that suggested there might be some problems with heat management in the hotend I was using. This hotend was actually a beta-test version I volunteered to test some time ago, and since it seemed to do pretty well I just kept it. But it always had some stringing problems, so when I had the chance to get a different version of the hotend I did that and installed it. Here is a photo of my string test with the replacement hotend:
Since this was horribly scary I started tweaking various settings. I tried changes to all the parameters I could think of: nozzle temperature, prime/retract length and speed, extruder adjust. The results all seemed pretty much the same. I decided to make a new test part that was simpler and quicker to print, and also wasn’t nearly as delicate – after all, I have never printed anything with tiny spikes like the part above has. Here is my new test part:
Still horrible, but at least it printed faster. So I continued making parameter changes and also changed the test part a little. I finally ended up with the following print:
It’s hard to tell from the photo, but there are strings only on one side, and they are fairly insignificant. What I did to get this result was to lower the nozzle temperature from 185 to 180. I put all my other settings back to what they were – the same as I noted in the original Preventing Stringing page. My guess is this worked because the thermal characteristics of the new hotend were quite different from the previous one, even though they actually looked the same, and all it needed was some reduced viscosity to help it eliminate stringing.
Here is the part pictured above after some simple manual cleanup:
If you want to try your own tests with this part you can download this STL file: stringtest2. And here is a 3D view of it:
Last Update: 13 May 2017