Sorry for so many questions but....

[yebon]

I started to measure out my board last night but i came to one part where i was unsure of the dimensions.  It is the knocks i do not understand where the 1/2 inch point is considered.  The drawing i am adding shows what i am talking about.  I know this is silly but this is how new i am at it.  The bow is a D- bow(slightly bend in the handle) 68" looking to get 40-50# at 27" Read oak board (home depot board) with a hickory backing.  Georges' board bow build along is a guide of what i am looking to do. Thank you for your help. 

[Ed Brooks]

Yebon, I believe you are looking for the 1/2" on the bow. your left marker. Ed

[PatM]

You want the nocks about half an inch down from the tip of the bow on the back side but the angle you file them at will mean that they are closer to an inch down the belly side.
 A lot of the location on an early bow will depend on your ability to form the nock groove with finesse. Give yourself some leeway to tidy them up and make them even. You may find that their position has shifted somewhat by the time you're done.
 There is little need to go much deeper than your actual string thickness as far as depth goes.

[yebon]

I am sorry maybe i am completely misunderstanding what it means.  I believe that i am now way over thinking it and i am making it much harder than needs to be.   here is another pic that may clear it up for me.  I apologize for this and i feel so dumb not being able to figure it out but if i don't ask then i will not know.  Again thanks

[Onebowonder]

The width of the TIPS should be around 1/2 an inch (give or take)  [I like 3/8 better myself, but let's be safe for a first bow and chase performance on the next one.]

The width at the nocks should be whatever the width of the tips are minus two times the thickness of your bow string. 

The THICKNESS of your tips depends upon your materials and your design, but in all probability it should be just enough to keep the last 4 - 6 inches of the tips from bending much at all when the bow is drawn.

EDIT to add - Length of the nocks is only as long as is necessary to keep the string from slipping over the end of the bow when it is drawn.  Less is better.  Excess weight out on the tips leads to hand shock and a slower bow.

I hope this helps...


OneBow

[Fred Arnold]

1/2" before you file the string grooves, as already stated by Ed.