Why won't the pins for the cantilever grips extrude?

gerald_comeau

I am still in Fundamentals 4, Mulit- Part Part Studios - Using Multi-Part Part Studios/Exercise: Creating Multiple Parts in a Part Studio and I am at Slide 14 and have completed all the sides from 1 to 13. 
The OnShape message that comes up after making several efforts to extrude is:  "Boolean resulted in no geometry change. The parts do not intersect or are totally contained."  I've gone over my grip sketches and everything looks OK. Where else can the problem be?
Once I get past the pins on the grips I believe I can go on to finish the exercise which also finishes this course.  I'm eager to go on to the next course which is Fundamentals 5, OnShape Assemblies. 
.....grateful for your help 

gerald_comeau

I believe I may have found my problem in Extrude 5 for the grips.  There were holes in the extruded grips and that was because I had not selected the the circle in the sketch profile. I edited extrude 5 and once I selected the circle the grips became solid.  I was then able to do Extrudes 6 and 7.  

gerald_comeau

I believe I may have found my problem in Extrude 5 for the grips.  There were holes in the extruded grips and that was because I had not selected the the circle in the sketch profile. I edited extrude 5 and once I selected the circle the grips became solid.  I was then able to do Extrudes 6 and 7.