Okay, so my tech graph teacher gave me a question from "Understanding technical graphics". If any of you have the book, the question I am stuck on is pg 92 Q. 3. Help?
I presume you are okay with the elevation and plan, and just stuck on the Development.
1. First off all you have to draw the "plan" of the object, followed up by a 15mm line above it.
2. Mark in the parts you already know, such as the 50mm line.
3. To get the development of the two semi-circles, divide into 6, joining each point where it meets the circumference.
4. Then get your compass and find the distance of the points you marked off, mine was 9/10mm. Mark off each of the 6 divisions to the right and left of the line above the "plan". You will then get the distance of the ring of 15mm height.
5. Copy out the "Plan" again, and follow up with a 50mm line directly above it.
I will include a link to a rough working out of what it should look like. https://gyazo.com/3c8d115d03fa36741435559774f508bb
Hope this helps atleast a little bit.