You'll need some lead solder wire - thickness to suit your requirements. Take a length and bend it in half. Then wrap the wire around a suitably sized tube/rod, ensuring the wire lays flat side by side....
Then take one end of the wire and carefully unwrap it, leaving the other wire in place. This will leave you with perfectly spaced coils....
If you want the spaces between the coils to be smaller, use a second piece of smaller diameter wire and the opposite obviously for larger spaces.
Gary
