knex weights?

Hey everyone! I made a knex bailsong (butterfly knife) to pratice tricks for when I get a real one, But I would like to figure out what mass it is so I can compare it to a real one. i dont have a ounce scale around here or dont know anybody that has one is there a place online where i can find the weights because i cant find any thing online

Does it say what each piece weighs somewhere? Because you could then count the pieces and multiply by their respective weights.
thats what i was thinking but i couldnt find anything on them
I would suggest getting a food scale (electronic is usually best) and measure the exact weight of many of the same type of rod (you never know if they changed the plastic composition overtime,) that would most likely be the best tactic, average it out with a mean, and your pretty much golden for getting weights, unless there is a HUGE variance (too much change) in the weight from rod to rod, then you'll have to seperate them into piles of similar weights...