I'm glad you like it...it will save much of you time...thou I sometimes sit and draw on paper as well.
If you don't mind I go by your list here...
1. to build the new pulleys
2. to design/ build a reliable way to attach the pulleys to limbs (here, i'm still debating with myself if to use 2 limbs with holes at tops, or to cut the limbs in 2 and to use 4 narrower limbs)
3. to build the fire rail
4. to build the stock (here I think that i will go with a very simple idea - some aluminum tube with a shoulder rest attached
5. to build the rope (I think that dacron is the most recommended)
6. some solution to cover the 1000 screws in the trigger mechanism Smile
7. painting, etc, etc - most probably there are a lot of things that i didn't thought about yet Smile)
1.Speaking of bearings...I know a place where you can get some really nice tiny bearings in practically any size and variety...from regular ball bearings to ceramics used in engines...here is a section where I hang out(look at the price and you'll see why
2. You are right in this moment. I know from looking at some crossbows that have a split tip are usually reinforced by thickening that area. If limbs are pressed into a laminate - a wooden "wedge" is used...sort of how the man did here(scroll down a bit to the compound bow)>>>Link
...if you decide to make split limb made up of two narrower limbs...I can see that you will most likely have to make some big or complex mounting brackets to keep the limbs from twisting. Let me know if I'm not making any sense.
3. Well the arrow track or rail or whatever the world calls it today(some people don't like to use term "fire" with crossbows
) You have chosen a pretty good design...in this type of crossbow I don't see an extreme need for rail rigidity as it doesn't need to support the draw weight of the crossbow when it's loaded...so what ever you do just make sure it is strong enough to support a foot stirrup without bending. Also a good note might be to fill the hollow space in the rail to quite down the crossbow as shooting it will send vibrations down the crossbow body making it humm like a tuning fork.
4. Sounds good to me.
5. There are better ones out there, but Dacron is recommended simply because it stretches a bit compared to the more expensive string materials that have much less stretch. The stretch is good for a reason...those stronger and less stretchy strings are very hard on the crossbow as each shot is a very hard stop that sends more destructive vibrations down the crossbow limbs and and other components.
Then there are also a few different ways of making the string...there is the "endless loop" method and the "Flemish twist" method of making a string. Both are widely described by bow builders. Advantages of The Flemish string(even thou it takes longer to make) is that it has additional amortization and can be adjusted for length by twisting much better than the endless strings...thou Endless strings are not bad and the speed and simplicity of making them also makes them an excellent choice. Don't forget to Pre-stretch your strings.
6. Cast, machine, or layer(riveting one layer to another) a dedicated housing perhaps
Interesting trigger you've got there...to be honest I don't exactly understand the principal of it's operation other than what you've already mentioned with the bearing retaining the latch...thou it does looks very familiar.
7. Well painting is certainly an interesting topic...for example I'm currently getting ready to spray my brothers stock to a carbon fiber cloth effect
PS: 3rivers sells it a bit more expensive than where I get it...what do you think about this guy...I've bought black glass as well as fast flex bamboo laminations from him before with out any trouble >>>Link