kudos to you! I like the rope, it is nylon correct? This is great material for people who have allergies too. It is easy to clean, and can be bought descreatly without everyone in the world knowing, "Hay I'm into BD/SM!" It is also something that is not very expensive, so adding a new peice to the toy box will not break the bank.
I see that you have bound the bottom of each tip. It looks like metal, what exactly did you use? If it is a close-er ring (sp?) I'm not sure how that would be against the skin with lots of force. Have you thought of sewing it closed? I applaud you in not burning the ends since this can cut the skin. Besides the rope, you could use duct tape since it comes in colors and is teeth frendly too. The coper tube sounds like it would be pretty. Maybe a carved wooden handle would be a future addition?
The rubber tube I believe will always go alittle wild. You could try tubbing that is a little stiffer, but I'm not sure how well that will flex.
For anyone thinking of trying flogging, please, for your safety and others. Read up on the topic, and talk with others who have done this before. If you do not know what you are doing, you can seriously injure the other person. This can be an enjoyable activity if you educate yourself.