I have been working on these myself this year. This is definitely the challenge to determine the spacing on the lights. I had used the spreadsheet to calculate out things, then once I had that I was able to determine the length of the helix. I used 70 count C5 LED strings and doubled them over which was perfect for the length of the helix I have. I was using 12 strings of lights (is plenty to start) then I built the tree structure and determined the length of the support wires. Once I had this I was able to figure out the spacing, I had 1 1/2 turns on each string so I had 16 connections on each guide wire, I took the length of each guide wire and divided it by 16 to figure out the spacing, then took a support wire and twisted loops at this distance to space the lights strings. I made 4 of these spaced 90 degrees apart and it worked great to get even spacing of the light strings. Be sure to tag the strings at the bottom of the tree, it is total confusion when wiring it up if you don't! I have similar budget constraints so starting with 2- 9' tree's with 4' base and 1 -18' tree with 8' base. Planning to just parallel all 3 tree's to a single controller and operate them all the same. Hoping next year to double it to 24 strings winding the tree's with a second colour in the opposite rotation of the helix.