I was wondering if anyone knew how to connect surgical tubing to make a conveyor belt.
Just tie the ends together 
or feed a string thru the surgical tubing and tie those ends together with a square knot and then tie it to the end of the surgical tubing
get the smallest zip-ties you can find. take four of them and with the first two make a loop by feeding them through each other. take the looped zip-ties and feed it into the tubing to make your belt. to lock it in place take your remaining two zip ties and tighten them over the large lock ends of the looped zip-ties.
i think melt and stick will work
edit: glue?
Tiny zip ties work well. We slit both ends of the tubing, like a snake tongue, glued them with rubber cement, and put two tiny zip ties around the joint. It seems to be holding up.
I haven’t yet tried this method, but I have tested the fit and it seems like it should work.
Take the two ends of the surgical tubing piece you want to join and roll them back on themselves a short distance (turn them inside out). Take a small piece of KOP pneumatic tubing and coat it in adhesive (not really sure what would stick best). Roll the surgical tubing over the pneumatic tubing and let the adhesive set.
When prototyping you may want to just put a wrap of masking tape around the pneumatic tubing. That breaks up the smooth surface of the pneumatic tubing and gives the surgical tubing something to grab on to.
It is also possible to order urethane tubing specifically designed to work as conveyor belt material. Check out the McMaster-Carr catalog on page 1018, or search CD for “round tubing”. You’ll find there is lots of discussion on the topic.
Jason
Your idea worked amazingly without any adhesive i’m sure it will work perfectly! Thank you!