im trying to create some involute splines using the gear c hook. i use mastercam in metric mode, im assuming the gear dll is imperial only as when i measure the drawing after creating  a 20 dp 15t 30 pa gear,(thats what my local gear cutting toolmaker measured the tooth form to be on a shadow projector even though the actual shaft splines are 25 tooth and 27.4mm od),  its under 1mm od ? is there a way to correct this without converting all the parameters to mm ? 

ive just broached internal splines on my haas tm1 with 4th axis sitting upright with the help of mastercam tech help. worked great,all done in mastercam 2020, made my own broach tool using a square milling tip,0.05mm depths of cut to 1.9mm deep.  27 splines 28mm od.

yam broach.mcam

hi, im trying to use gear add in,mc2020, input 14 teeth, all,  i input od of 25.80mm , root diameter 19.4, then either 15.8 as the diametrical pitch, or 1.61 as the module.then the diameter drops back to 1.012 it looks right in the preview ,but when i insert into mastercam the diameter is 1.012.what am i doing wrong,or  do i have to scale it back to the correct size, thanks neil