Good job. Nice to see some DIY equipment.
If you back to back two rake heads and cable tie them with the metal ties you get a big rake, maybe too effective as you may need a whole army to pull it out depending on how weedy the place is!!
I use them, only had 2 outings since they were purchased but so far they are fantastic. So much better build quality than Delkims and definitely on a par with the equivalent fox alarms