I do have the Type C set with 30 cams. It may be a mechanical problem. The upper arm seems to work fine at the white arrow setting, but the lower arm is not coming out at the red dot setting. It stays where it is and does not come out and touch the cam. At the white arrow setting, both arms engage properly. This one may have to go to the shop. Or wait until I go to take the repair classes next spring. I'm supposed to take @ 5 non working machines. I just wanted this one to work now! (kinda impatient)