Braid to downrigger spool

How should I attach the braid to the laketroller spool?  I can't remember how the cable was attached via the two holes.  Or should I arbor knot some mono to fill the spool a bit then attach the 80# braid like I do on my reels?

I use mono backing as you describe, but I'm curious what others do...

I use electrical tape on the spool and use an arbor knot.

I left ~10 feet of cable on the spool and tied the braid straight to it with an Albright knot and a drop of super glue. There is plenty of braid on there, so I'll never really put that knot to the test (I pulled HARD and couldn't break it with my hands).

cable to braid, that would've never crossed my mind.

i ended up putting 40# mono first, then filled the v section of the spool.  i then tied on the 80# braid, with enough to spare in case i need to cut the line (~200ft).

ended up ditching my custom mount which raises the DR spool up 1/4" so i can mount it on my existing flush mount in the outback tray.  for now, i'll use an extender until i make a 1/4" spacer to place beneath the flush mount to raise it a bit.  i didn't want to use a deck mount because it protrudes above the trays.