can someone post pics on how to serve a string knock on top and bottom?  thanks

Look in the How To section - there are several

what I do..sorry no pics..is this.

Lay the bow on it's side while braced.

Take some serving line...8"-12".. enough to hang on to and pull tight.

Tie an overhand knot around the string ( like the first knot of tying your shoes)

Make the knots the same way each time.
I use " left over right and under " This lets the knots "stack" evenly.

anyway..
Tie the 1st knot. left over right, under..pull tight
Flip the bow over.
Tie another knot on the opposite side of the string..left over right, under....pull tight

Repeat flipping and tying until you have a stack of 5 knots or so.

Once you tie the last overhand knot " left over right and under"
Tie another overhand knot right on top of it..don't flip the bow.
This time though use RIGHT OVER LEFT AND UNDER.
Pull tight.

This will complete the nock with a square knot.

Then trim the excess string so it has about a 1/4" tail.
melt that tail with a lighter and while hot press it smooth with your finger..DON'T HEAT THE ACTUAL STRING SERVING!

I like to work from the center out. So the final knot is away from the arrow.

So you make one of these knot stacks on top of the arrow nocking point and one below.

You don't have to use serving line.
You can use floss if you want.
But if the line is too thin you may have to tie a second stack on top of the first.

here's a vid.

This guy doesn't flip the bow..just ties upside down.
and does a double stack.
I just find flipping the bow easier..lol

Anyway, you'll get the idea.

 http://www.youtube.com/watch?v=wMqTmLmMPjg

There's a couple of other good video's  I'd recommend, with a little more detail. One's on this site; I forget the poster's name, he's from Hawaii and is a great resource.
Other one is by Rick ******, found it on another site, and it's the one I found most helpful.
One thing Rick points out is that you want the nock material to be at least as thick as the serving material, and after using thinner stuff I see why!

http://s152.photobucket.com/user/mcdavid1944/media/Stringnock.mp4.html

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=107748

http://www.youtube.com/watch?v=j8EghWvyUcA&feature=youtu.be

I use 80lb braded fishing line. It works great. The guy at the local tackle shop sells It off his bulk spool by the foot. It's cheep

Here is a easy to do whip_tie_adjustable_nocking_point on you tube.

http://www.youtube.com/watch?feature=player_embedded&v=1YlYqDiJN8U

+1 Rick ******.
He uses a nail knot.
Using a piece of a soda straw rather than a pencil or nail is even easier.
 http://www.animatedknots.com/nailknot/

I could not make Rick's knot work for me.
I even called him and complained about it.

He laughed at me, and asked if I paid attention to the part about pulling them tight. I had to answer no. 8(

They work better than anything I've ever done now.

LOL - "Read The Instructions"

I tied one on my new longbow, works great! I like it way better than a brass nock.

Hi

Just the thing I was wondering - the tribe were there again!

Thank you!!

Gotta say Rick's adjustable tie on nocks work - even for someone as challenged as me when it comes to tieing knots.

Ditto on Rick's serving knot have them on all my bows!