http://www.amazon.com/SODIAL-Portable-P … B013OCFFSW

Does the measurement reset to 0?  Most calipers of this type only turn off the LCD, so if you jiggle it, it should wake up with the same measurement.  When I've run these powered from an Arduino, the LCD still turns off but it continues to send data.

With a thickness gauge you can try filing the edges of the plunger and anvil, but it still isn't very forgiving of kinks.  If you try bearings, you have to make sure they are as perfectly parallel as you can get them.  Also make sure that it isn't possible for anything to flex.  If there is too much spring tension, something might bend to part the bearings rather than only sliding the caliper.

I have a external 16x2 LCD screen displaying the results - first line shows the filament diameter and second line shows the average and current counter, currently I zero out the reading after 50 readings. I know when the gauge goes to sleep/shutdown because the data on the LCD screen (especially the counter) does not change. I'm running mine with an Arduino Uno, but the gauge still has it's own battery, I guess I could remove the gauge battery and power via an LED through to the 3.3v on the Arduino. It's interesting that your setup continues to send data after the gauge goes to sleep/shutdown.

Did you ever find an answer?
Also are you still using this?
I tried this, but it really didn't work well since the filament is going sideways against the shaft and would catch a bit.
I'm almost done with a new design which will sandwich the same sensor in between two bearings, should work better, we shall see.

Unfortunately I'm still looking for an answer.

I find the same thing with the shaft getting caught, and the filament not lining up, I have to cut the filament end to around 45 deg angle before feeding, once I get the filament through successfully it works great. To save me bending over/under to read the thickness gauge I connected a 16x2 LCD screen so I can position the display at a better position, I modified the Arduino program to display the diameter of the filament on the first line, and the average on the second line.

With a thickness gauge you can try filing the edges of the plunger and anvil, but it still isn't very forgiving of kinks.  If you try bearings, you have to make sure they are as perfectly parallel as you can get them.  Also make sure that it isn't possible for anything to flex.  If there is too much spring tension, something might bend to part the bearings rather than only sliding the caliper.

Thank you for your assistance.