Robert, the pen mandrel set up will work for making calls with the rubber thingys that hut sells to adapt them BUT, you will be much happier with one of Chad's mandrels. I make alot of calls, That woulod be ALOT and the rubber thingys do not hold up well. The big difference maybe the only difference between turning call and a pen is the size and shape. The guts of course are another story. They can be the mst frustrating of the whole process. Getting them in right and then getting the sound JUST the way you want it is a challenge. My advice....Go for it and have fun, make one up and run with it.