Are you saying that you have two sticks that are too short? Do these parts get reinforced in any way?

I suggest you replace them with full length pieces if that's the case. I would not use CA for the splice. Carpenter's glue or epoxy should work.

If you use carpenter's glue be sure to double-glue the joint. What that means is you put glue on both parts, give it some time to soak in (a couple minutes), then apply more glue and put the parts together.

I'm not really clear on what you need to splice though and it makes a difference how the component is built.