Hi Everyone, I have an Acra 10x54 with a Frejoth head on it. I need to replace the collet alignment screw and to do so I need to remove the dust cover at the bottom of the spindle. I have removed a set screw on the back aand I believe the cover is supposed to unscrew. I cannot get the cover to unscrew no matter what. There are two holes in the bottom that a spanner fits in but I just cant get it to budge. I can see what looks like pins ineach hole, they do now move or push in and they are not hex screws. Has anyone come across this issue? Sorry but it looks like I cant add pictures.