Summary

A (very) old vacuum cleaner had a broken attachment that joins the main unit to the hose.

Measured and designed the profile of the part in sketchup, did a 'Follow Me' to make it a cylinder, then exported to STL, printed on a Replicator and voila... problem solved.

PS: This video helped with using the Follow Me tool in Sketchup: http://www.youtube.com/watch?v=OL7jvE9So6c

Instructions

When using ReplicatorG with the .STL file downloaded from this page, I'd suggest ensuring the model has the hose attachment on the platform, and the end that locks into the cleaner is at the top.

I printed with 50% fill (for it to be strong) and with full support & a raft. Some external diameters are larger than the original part (where it made no difference to function), also for added strength.

On finish, remove support material and check the part in the 'socket' of the vacuum cleaner. If it doesn't turn and lock, sand slightly behind locking tabs as well as the main face that meets the cleaner until it does.

Suggest using soap and water to assist refitting hose over barb tail on other end of the part.

Suggest improvements:

The protruding hose barb fitting could meet the main cylinder in a smooth chamfer - would add strength and make fitting the hose a bit easier.
4 x supporting ribs on the remaining exposed section (when assembled) would help the part resist breakage given the hose will apply fairly strong and regular lateral forces when in use.

PS: My second designed and printed object using Makerbot Replicator.

Hoover Vacuum Cleaner Hose Attachment