Help with Nylon. Head and bed temp

I recently bought the 3mm Bridge Nylon for my Lulzbot Mini and am having a great deal of trouble printing with it.

I started out using the Cura proifle for Nylon Bridge provided by Lulzbot
According to the manufacturer’s website, the nylon bridge should be printed at 245C-265C with a bed temp of 45C. When I set the temp in this range, the filament would dribble out uncontrollably. After trial and error, I got the plastic to stop dribbling at 215C, which is significantly below the recommended range.
On the test print, it would start out fine, but after about the 6th layer, the piece came off the bed. I figured this was a print bed temp issue. After trial and error, I had the bed temp all the way to 75C.

Does anyone have any experience with this filament? Should I continue pursuing these odd temperatures, or could there be a larger issue at work?

Thanks!

I have some experience with Alloy 910. I have found that bed adhesion is excellent with the PEI surface thoroughly covered with PVA from diluted Elmer’s Glue. Glue stick also works, however, any gaps in the PVA coverage will not stick, and these unstuck areas grow as the print progresses. Taulman’s recommended 45C bed temperature works well for me. To remove the part, I soften the PVA by increase the temperature to 80C.

Bridge Nylon does not adhere to the bed as well as Alloy 910, and so you will have more waste due to loss of bed adhesion or warp. Follow Taulman’s recommendation for 45C bed temperature.

The 100C bed temperature currently recommended on the Lulzbot Cura Profiles page is too high. Note that PVA’s glass transition temperature is 80C. At 100C bed temperature, the softened PVA is ineffective at binding Bridge Nylon to the bed, and a part of any significant size will pull away. Alloy 910 parts can sometimes be printed at 100C bed temperature, but the material still performs better at a lower bed temperature (my tests are with ~20cm diameter parts).

I’ve experienced a bit of the same issues with excessive filament leaking out of the nozzle at the recommended print tempreatures. I’ve found that it’s usually caused by excess moisture in the filament, nylons love water.

You can try to dry out the filament in a sealed bag with some desiccant or bake it out in an oven, here’s a pretty good guide: http://stephanfr.com/2014/09/07/printing-with-taulman-bridge-nylon/

I’ve found that having the bed at 100C helps with warping on really large parts, but the lower temps should be fine on a mini as long as you’re using glue sticks.

Hope that helps!
-bam

New to the Forum. But have found it very helpful. Our Company has the Taz5. With the new enclosure HIPS and ABS print very well at nozzle temp of 240 and bed temp at 110. However, I too have had major issues with Nylon (Bridge). I have acutally printed with a brim and, while printing, carefully taped the brim down with blue painters tape. It is not the best solution, but it has helped to get some tooling printed.

I have had great success with Alloy 910 with printing temp of 255 and bed temp of 45. I thoroughly cover the bed with liquid PVA and let it heat until it is completely clear. The issue I have is that you have to peel off the PVA and re-cote between prints.

Wow, bam - thanks for this post. I was going crazy trying to print with Alloy 910. I tried everything I could think of but just got messy, unusable prints that were hard to get off the bed. Then I saw your link to the Stephan Freidl article. I just finished printing the rocktopus after drying some filament overnight in the oven, and it’s like a miracle. It looks as good as my best prints with any other plastic, and it came right off the bed! (I was using Elmer’s blue glue stick on the Mini stock bed.)

It’s unbelievable how hygroscopic nylon really is. I wouldn’t have believed it if I hadn’t seen it myself this way. Thanks again!

Allan