Quote Originally Posted by JAZZCNC View Post
Yep 6 + 3.!!
Doesn't matter if the recess or slot is wider than the carriages. What matters is the slot has a Machined reference edge which the Carriage Reference edge sits and registers too. Again look at the picture of the Gantry uprights (bits8) the long slot with 4 holes is for the Carriages and the top edge registers against the carriage Ref edge but the slot is 1mm wider than the carriages. Having the slot a tight fit would make no difference other than making it harder to fit.!!
If I have read this correct, the top edge "registers" with the carriage (i.e. points it in the right direction?) but does not actually have a close/touch fit with the carriage?

Another question regarding clearances... I am in the process of adding milled out sections in the end plates to locate the extrusions. Should I allow an additional margin (say 0.5mm??) for the extrusion? Or should I design an 80x80 slot with 4mm radius corners as per the extrusion?

Thanks,

Dave