In what ways is your system different from a typical melting point rig, (and can you find an example in your text book -- online sources I've found aren't clear.) Your write up should explain how your rig will compare to known methods.
Are you using proper melting point technique? You seem to be using a capillary tube, that's correct. Do you know how much sample to use and how to pack it?
Whatever happens, you won't be putting the instrument manufacturers out of business with your high school project. What you want to do is explain how good of a job you're going to do with what you have, and that you understand your systems limitations. That's what the instructor expects.