Y-axis keeps getting stuck

[Aardvark]

I just finished a cut with my CNC. When it wanted to return to the workpiece origin, it seemed stuck in the Y-axis direction. When I wanted to move it manually along the y-axis, it kept getting stuck while making a higher pitched motor sound when stuck. Homing it works, because it moves slowly, but when I move it on the fast setting, it keeps getting stuck, in random locations that are not consistent. Some information on the last run:
1/2" end mill with cuts being up to 2" deep in multiple steps. The bit didn't get hot, everything worked great. What I couldn't use was the dust collection, because the cuts were so deep. So since there was a lot of hogging out, there are a lot of shavings everywhere.

I checked the gear track, which is underhung and therefore protected from dust and shavings and I can't seem to identify why the machine keeps getting stuck. There's nothing blocking it. What am I missing? Is there a proximity sensor somewhere that might be caked in dust? Turning the machine OFF and ON again doesn't fix it...

Thanks for your help!

Here is a video: https://drive.google.com/file/d/1HClh39fgXhKAHIa_UPY9SG8BG6E1yA4s/view

[drew]

almost without doubt it's hanging up on the helical where it comes together on the non-oiler side. 

first off, you likely need to tune her up a bit... remove the covers on both sides, then loosen the motor on only one side at a time- push motor into track as hard as you can by hand, and cinch a bolt down when satisfied and still holding the motor... tighten the rest of the bolts... then do the other side.

i highly recommend you slow your rapid jog speed down to no more than 6k- these guys seem to want to hang up on that union of the helical rails when hauling ass--- it only takes the slightest of hangups and now the Yaxis motors are out of sync and fighting themselves.  so... slow that baby down some and you'll likely not pull your axis out of perfect square or hang it up again.  ...... this is precisely what happened to me and mine, and how I recovered it. 

put that 'tuning' tip in your toolbox and use it every six months or 1000 hours and you'll likely not encounter it again.

[Fontao]

I was having the same problem but I just slow down from 120% to 100% and that was that