Awhile ago I added a shuttle race extension onto my Macomber:
As I was using it, I kept thinking that it was about half of what I needed to make it into a fly shuttle. So I did that over the weekend. Here is an overview picture
You can't see the top, but it's attached to one of the top railings of the warping trapeeze that I make awhile ago. (http://weavolution.com/group/home-built-equipment/diy-warping-trapeze-19615)
The shuttle in it is a Schacht end feed shuttle. I've tried the Buster Bay in it also, but that doesn't work as well since the shuttle itself is not carved symetrically, but bends to one side. Here is the shuttlel box:
And here is a better picture of the "pusher." Notice that it's made to push the shuttle into the reed. This keeps it from flying off at the other side.
And, because I like to use a floating selvage, I added a chord behind the reed to do that, using the idea that BigWhiteSoftDog posted awhile ago.
You can see the chord raising the floating shuttle from behind the reed. It works amazing well! BTW, that piece of white behind the shuttle is a piece of cardboard I put in on each side of the reed because the reed that I'm currently using, while wide enough for this warp, is too narrow for the loom. I was afraid the shuttle might sail into the shaft! I haven't stained the wood to match yet - I wanted to first see if it worked.
There is a little brass "fin" that helps guide the shuttle into the box. Because of the railings that the pusher rides on, once the shuttle starts into the box, it's not coming out!
I'm still learning exactly how to jerk the chord to get it to work smoothly and to get my weaving rhythm down while using it, but that is my learning curve. The contraption seems to work very well.
That's pretty ingenious!
Something you may find even simpler Sally is a rectangular box, with a sliding wooden picker set in a grooved track of the front and back sides of the box (inside). Even better, would be to route a slot part way insto the sides and have the picker with SS rod mounted on the sides (2 per side) that run in the slot. Counter sink an eye bolt on the bottom side that the end of the shuttle passes under to reset the picker to the back of the box. Then that nut won't damage the shuttle. I'm thinking the way you have it rigged might cause ramming. Another method was to use a rod over head, but also grooved sides for the picker and the rod would help guide the picker better. Also, you might find your fenders too light. I had light SS when I started out with the first fender idea, and if that shuttle hits that fender with enough force it will bend it, over time it is weekened. I replaced it with 3/16" SS and that will never bend. Steel is stiffer than brass. If you have a router, a drill press and a chisel or two, you can make a nice flyshuttle and use SS inserts on the ends, and use rubber or leather backing at the back of the boxes in case the shuttle goes a little further back than expected, won't beat up the box. The inserts are pointed end caps for tube holders like this.
http://www.leevalley.com item#'s 12K34.07 and .08
Epoxy them, so there is a good smooth transition from the end cap and wood, to prevent snags of finer threads.
I would also recommend incorporating a little bit of a runner that runs the length of the box, past the fender and a little under your warp. Use a longer taper on the end under the warp like a small ramp, but not one to cause it to lift into orbit, gradual and subtle. :) Some warps because of the draft are not always flush with the race, if you have more than 4 shafts, unless your race is slanted at an angle. An angled race may not work well if it causes the uprights to be in the way of the fly shuttle and can be damaged. Just easier to make a little runner that adjusts with your shuttle boxes to elevate the shuttle some to prevent skips.
Anyway, just some things to think about if your design here gives you troubles.
I would be pleased if I Could see the pictures. Is something wrong with my account?