Effective Training Inc. Message Board

On page 283 of the Self-Study Workbook (2nd) edition, question 3 asks what controls the parallelism of the specified surfaces, and what they are limited to. The answers for both surface B and C in the back of the book puzzle me. Well, first of all, I guess my initial question would be...parallelism with respect to what??? Regardless, the answer for surface b is that it is controlled by the flatness, and is limited to .1. I don't understand how flatness is an indirect parallelism control. Similarly, for surface d the answer is that it is controlled by the perpendicularity control, and is limited to .2. Again, how is perpendicularity an indirect parallelism control?

I am using this book to teach a class, and my students asked me about this. I hope someone responds so I can explain it to my students.

Thanks,

Keith

Hi Karl,

A very good question. You discovered a typo in the self study book on page 283. The question should read "The flatness of surface ...". You will notice that the answer in the back of the book states flatness. The question and the answers will make sense with this change. Parallelism and perpendicularity are indirect controls for flatness.

Keep posting your questions and checking back for the answers. We will be posting our replies regularly.

_________________
Best Regards,
Roy Cross
ASME GDTP Senior Level S-0488
Dimensional Engineering Mentor
Effective Training, Inc.
2118 S. Wayne Rd.
Westland, MI. 48186
royc@etinews.com
http://www.etinews.com

Roy,

Thanks! I thought I was crazy!

Keith