i just got a porter cable 18 inch scrollsaw and seem too have two issues. first i use spiral blades, unpinned and i cant seem to get the blade tightened without it twisting and breaking.second thing is the blade doesnt lift enough to feed the blade thru th holes.i normally don,t go thicker than 3/4 inch wood and the arm doesnt lift high enough to insert the blade from underneath.am i missing something or should i go back to using my old delta.