So this weekend I did.
Actually I made two.
My dogs are bigger than Koira from So Fly, so I went with a much heavier duty spring as I not only foresaw my 40-50 pound dogs going to town on this thing, but I also wanted to eliminate anything breaking from more than one dog tugging on the same tug.
Koda (on the pink tug above) loved it and spent the most time on it. I thought for sure Demo would love it as well, but we had to hide his jollyballs and encourage him to play, although you can see that he did get into it for a bit.
The tugs are on carabiners so I can easily unclip them from the spring and bring them inside so the dogs are never unsupervised with the spring poles.
In all I spent $45 on the two, not including the tugs since I had them on hand.