BG111737201 thank you

BG111737201 PTFE is a lubricant which does not attract dust hence the name “dry lubricant “ used sometimes. I used it as a spray.

BG111737201 Did you get the A option? Did you receive 1 or 2 pieces?

BG111737201 Irecently received mine and is also not square. I wonder how they mark them as accurate according DIN875/0.

BG111737201 Did you check for precision? Mine has 89.3 degree and i checked it against several other tools

BG111737201@JunhanYu ifthe headpiece doesn't sit inside the channels it will never be in the same place in relation to the tracks. So the dimension markers are no longer true and certsinly no guarantee on perpendicularity. the problem is not the groove on the headpiece but the bowing of the track in the sectional plane as it brings the channels closer. In theory one can force tightening the screws on the headpiece but could shear the thread which will render the whole bit useless. Banggood asked me to consider a full refund but I need to confirm the potential cost for return to China from England. It would be much better for them to arrange a collection as it is likely they have a courrier business rate account. I'd much prefer for Banggood to send a pair of track segments as replacement.