I proudly present the Monoprice Select Mini Space Eraser , specifically engineered to facilitate printing with TPE-80A flexible filament. Yes, I tried printing with the rubbery stuff and, no, it did not go so well.  No amount if fiddling with the temps, speeds, nor flow rates would stop the filament from going out the wrong way from the feeder instead of down the Bowden tube like I wanted. Yeah, I knew I was pushing it when I bought the filament but I'm not the kind to just give up.  So, I stared at it for a while before deciding it might help if I filled in a few of those annoying gaps... figured all I needed to do was pack in some washers here, get a bit of a plastic fork over there, and somehow clip it all together so it didn't .... WAIT A MINUTE!  I have a 3D printer!  So, after a bit of not overly careful measuring and more successive approximations that I care to admit, I came up with this design. The purpose of this little engineering marvel is to occupy the space where the filament wanted to go instead of down the tube.  It locks in place well enough and does the job as intended without incident.  Yes, a Monoprice Select Mini, complete with Bowden tube, can print parts out of TPE-80A filament, which is some pretty neat stuff. No idea if it will fit your feeder; it's pretty custom to mine and it did take a bit of filing in the end.  But, if it doesn't fit, you can always use it as a starting point to draw your own.