First a WARNING: These hose clamps will only work with single-barb fittings. To make these for other tubing sizes you will need to adapt the measurements. I made these specifically for 1/2" ID 3/4" OD because there's a complete lack of variety when comes to fittings for that size of tubing.
Here's how they work.
1. You slip the compression cuff over the barb with the narrow end away from the tubing (if you get this wrong you won't be able to get the tubing on)
2. Slide the tubing onto the barb and into the wide end of the compression cuff
3. Twist and pull the compression cuff upwards until the centerline of it is as close to where you think the underside of the barb head is. With clear compression cuffs this location becomes fairly obvious by how tight the narrow end of the cuff gets over the tubing.
To remove reverse the process.
I've done a bit of testing with these and they've worked great so far and I've decided to allow everyone to try making them.
This are REALLY easy to make with a lathe if you simply order 3/4" ID 1" OD polycarbonate tubing and then cut sections of it to length. It might be possible to make these with a drillpress if you have the right drillbit but I wouldn't recommend it.
.81" ID is what worked best with my tubing but the widened end is really just there to act as a lip to help wedge the tubing onto the underside of the barb head. That means to widen one end you'll need either a 25/32" or 13/16" drill bit or a boring rod.
Some light sanding with 300grit sandpaper in the narrow end of the cuff will probably be required in order to allow it to slide on the tubing when dry.
And the best part of all:
These things are DIRT CHEAP TO MAKE. 8 feet of 3/4" ID 1" OD polycarbonate tube from mcmaster (part# 8585K35) costs a meager $3.78 and yields around 50 compression cuffs. The only noticable expense is time.
I'd like to see more people test this for themselves and this is pretty much the only community I know of that has enough capable machinists that my be willing to try.