Having trouble printing, possibly moisture or combing

I am having trouble printing this part and wanted to ask if anyone has an idea of what could be causing my print to have a bubbly hard surface that is brittle. I think there is a chance that there is moisture in my filament but why? I dried my filament in my enclosure 2 times already for a total of 8 hours at 90 degrees F. On top of that, I also keep my filaments in a large dry box with the box filled at least 2 inches in silica beads. So I don’t think it could be moisture. But another reason I think it can’t be moisture is that it happened abruptly so I has to be slicer related? Here is a photo

It could possibly be because combing mode was enabled and the slicer decided not go over the entire part during the beginning of the print?
Please share your thoughts and opinions.
If you are curious about what I am printing or what filament type I am using: Using Matter Hackers PRO series RYNO. Printing a glider. Printing with thin walls.

If you print another similar object, do you get the same abrupt change at the same height?

I will give that a try thank you!

I printed 2 other objects and got the same results. I did tweak some settings during those tests which made them less brittle. The other 2 tests still had bubbles on the surface. What I did tweak in the slicer was the layer time, it was originally 5 seconds but I changed it to 2 seconds. I also changed the mode combing to off. During all the tests the bubbling happened at the same layer hight so it has to be slicer related right?

That high up, it could be some gunk on the z screws interfering with the z lift by causing since missed steps. Give them a good clean and fresh grease.

I almost forgot! The printer will sometimes have short pauses in the print each lasting a couple of milliseconds, it is like it needs to slow down or something. Also I think I saw the printer going faster and slower on different layer heights for some reason. That is why I thought that the layer time had something to do with it although it did not.

Not sure if this applies but it doesn’t hurt to ask…are you printing from an SD card or from a laptop/PC via USB?

I am printing from an SD card

It’s a slicer issue! I need help fixing this Gcode. Note: Only after the file was exported to the SD did this happen. I reloaded the G code from the SD and got this.

Interesting. Is it done with Cura LE and a completely default profile?

It seems more likely that it’s a problem with the source geometry and the slicer is trying to interpret some rounding errors once it starts to taper inward.

Can you post a link to the original STL?

Yes it is Cura LE. I modified a default profile to the settings that the maker recommends because of the need for thin wall printing.

I am not sure if I should post any of the STL files because I bought them and they clearly state not to share them with anyone.

If you are curious, company I bought them from: SoarKraft.com

The model is the Pika MH32 4 servo

Looks like about 1 minute of CAD to recreate a new STL for the front nose cone it if you give me the overall length, length of the uncurved section and wall thickness.

Still trying to solve the issue. I might try updating Cura LE to 3.6.38

3.6.38 isn’t much of a change. Go for the 4.13 beta.