Nylon Print Warped?

So I just had the second half of my window motor encoder project fail twice- first was with ABS, and I don’t think the bed was hot enough. I decided to switch to nylon given the application, and I just picked the failed nylon print up. I don’t know what happened, but for whatever reason, the bottom of a free-hanging part on the print is warped. In other words, the dimensions are correct on top, but not on the bottom, of the free-hanging part of my print.

Is it possible that my nylon filament has absorbed too much moisture? I printed in the X-Max, with the cover on and a plastic bag taped over the access hole; that seemed to work fine in my last nylon print. Though this one is considerably longer (30hr). Whenever I’m not using the nylon filament, I keep it in a vacuum-sealed bag.

Anyone have any idea of what may have gone wrong?


(the bottom is supposed to be hollow)

Maybe @Devmani or @dash3811 can help and they just didn’t see this here in “Misc”.

Looks like some under extrusion in the 1st photo. Also what’s your supports look like? Can we get a photo of the stl to see what the finished is supposed to look like?

The supports are around the circular rim in the first photo. Here is what it should look like:

I printed upside-down for that run, I will also try printing as shown.

By upside down so you mean compared to the photo of the stl? If so then the lack of supports could be the cause of it. Also it is recommended when using nylon to use a dry box if you print is long. By long they mean around 6 hours. Since yours would be extremely long then I would also stand to say that it’s a possibility that it absorbed too much moisture while printing. As long as you haven’t dried the filament out since your last print, the easy way to check is to take the end of the filament on the roll and bend it. If it snaps off easily then it has absorbed too much water, if it bends then most likely you are good.

Circular shapes come with their own complexities. I would assume that’s why they have the stl arranged the way they do. Plus the taller the print is the more likely it is to warp.

By upside down so you mean compared to the photo of the stl?

Yup. There were supports but maybe having it print on the side that doesn’t require supports is best.

I just dried the filament out and it bent, so I think it’s good. I can’t get a dry box by Thursday so I will do what I did with the last print and seal the X-MAX. That was an eighteen-hour print and it turned out fine.

One reason could also be that you are printing nylon with the brass nozzle. Nylon is very abrasive and I would expect that the opening of the nozzle is no longer the size it is supposed to be allowing more filament to be extruded than should be. There is a steel nozzle setup in the drawers by the 3d printers you should have been using instead. It is a simple plug and play thing to swap out. Just requires the removal of 2 screws from underneath it.