Modern crossbow project

[Tom]

After I had seen JSR's thread about his 6mm crossbow project I wanted to build my own. This time it's non pneumatic, but maybe when I have success I will make one with a piston.
The plan to use 40MM white PVC, some 16MM and 18MM OD PVC pipe, for the rubber band I chosen a very powerful muscle band(for image see below). The trigger mechanism is still a problem because allod of pressure will be put on the sear, I think a laundry washer trigger wont work, any Idea's ?.
G's from the Dutch, Tom

[f.c]

i made a crossbow not long ago. the problem with the pvc is that it soon becomes brittle . try using wood (what i did).

[TurboSuper]

If you use a rubber band, or any sort of elastic material, then it ain't a crossbow.

[STHORNE]

If you use a rubber band, or any sort of elastic material, then it ain't a crossbow.

depends if the limbs are flexible and how elastic the rubber band is, but in this case you're right.

[Tom]

If i cut the half of the 18 MM OD PVC pipe then it will be flexible is that an solution?
G's drom the dutch, Tom

[Jared Haehnel]

Yes it probably would be but it also isn't very rugged and probably wouldn't store all that much energy before breaking.
Try spring steel a good example would be a leaf spring from a truck but you probalby want something smaller then that. Leaf spring from a utility trialer perhaps? You could also use wood or i your really good fiberglass.

If you use and elastic band you've created a fancy sling shot not nessarily a cross bow....

[STHORNE]

or you could try welding a stack of sheet aluminum together. I did that once and it held a lotta power! I measured its draw back and it was about 45-50 lbs.
Just like 3-4 sheets (1/16th) should do the trick for this project. I used 7 sheets for mine but that's because i was launching soup/soda cans.