Can I use parts of an existing invention for something else?

You can file it as an improvement patent. Provided that you do not have all of the elements in any claim of the patented device/sport you wont infringe. If I can be of further help please call.

What you have could be patentable, even if it uses something that exists are ready. Improvements can be patentable if they are new. The first step is to find out whether it is new. You can try searching yourself. You have nothing to lose. Go to USPTO.gov, the official United States Patent Office website, and look under e-business. Try keyword searching on the advanced search feature. If what you have looks new, you should consult a patent attorney. You may be recommended to a professional search which can cost around $1500, depending upon how much work is done looking. I prefer a small lawyers office specializing in patent law. So-called invention companies seem to offer all sorts of services, but you need to speak with a lawyer who can guide you as toward what you should be doing and who is familiar with this business to avoid wasting resources on things that you may not need.