You can print flexible using this upgrade with Smart Extruder +. Normally, flexible filaments wrap around the gear. This part closes that gap and pushes the flexible filament to where it needs to go. When I describe this part to someone, people ask me, "Does it affect the regular PLA prints?" No, it does not, depending on my 2 years of experience. The profile provided is mainly for NinjaFlex, but it worked for all flexible filaments I have tried.
USING AN OLDER SMART EXTRUDER?
The older version of the part for Smart Extruder.
Important notes and warnings:
Opening inside your extruder will void its guarantee.
Sadly, MakerBot Print still doesn't support that much setting to be changed to print flexible. You can experiment with that. The only way to use it is to use MakerBot Desktop, which sadly doesn't support the newer printers. So, this is only for the 5th gen MakerBot Printers, for now (9th June 2017)
I had extruder issue which might be related to using this part, might have caused the gear to be worn out. Though, that problem only affected the filament jam detection, but not the printing. I have been using this part on that extruder for one year. I am not sure if the problem was caused because of using this part, but still, I am planning to design a new version which doesn't press on the gear much.
The photos are from my previous design for Smart Extruder. Now, I don't have any photo of this new version. I will be adding photos of this version shortly.
"Standard" print setting on MakerBot Desktop
Use MakerBot's filament. The dimensions are critical. I have worked with MakerBot filament. In other words, it is tested with MakerBot filament.
Create a new printing profile on MakerBot Desktop at the settings window. Press "Edit in Text Editor" button at the bottom right-hand side. Delete the text and paste the provided text. Save and close.
The part has a predesigned support. You can easily realize that. Remove it. Disassemble the cover and the gear of the Smart Extruder+, insert the part, will cover the gear, and re-assemble.
I am 16, I am working on developing it for more than two years. I think I reached an unbelievable stability. I designed that on SolidWorks. I made 16 Smart Extruder and 2 Smart Extruder+ prototypes. I am still working on improving...