One Step Forward Two Steps Back

After editing the PBasic code so the positioner moves the cars forward - stops at the end limit- moves back a little slowly - then moves forward again slowly to the limit: the cars seem to get positioned correctly : the brake catches the axle. Other than that all seems to work ok ... the Perlite coal works ok .. it gets caught on any available ledge, so i guess i need to remove any ledges, huh. It piles up at the back edge of the hole, but not enought to go over the back edge i made... but that is after only 3 cars... Time will tell if it piles too high... once i get it running i will leave the 'trash' a while to see if it collects too high.