My way is probably not what you want to do BUT I thought I'd mention it. I actually build a permanent platform & don't mess with those arm things & metal brackets.... I get 16' treated 4x6's - they are not actually that expensive. I dig 4' holes and line things up PERFECTLY. Put those rascals down & cement in with around 3 bags of 60 lbs quick-crete. Build a solid as heck bracing system all around. Then, I build a perfectly level platform on top with 2x8's (everything treated of course) bigger than blind so I have a couple feet of standing room to get in blind. Everything I need strong is bolted with lag bolts after securing with T25 hex screws that are for outdoors. Then, I lag bolt the blind to the platform like crazy. If I'm worried about wind- I'll get some earth anchors on ground (in ANY case you will want to do this no matter what you do!) & tied them to above. Bullet proof!!!! Solid as anything, no worries, not expensive and doesn't take a ton of time, really doesn't. OH- and getting blind up, some might disagree but I use a 7000 series john deere with loader, secure on loader (not hard, I promise) - raise it up carefully, push in on, line up, fasten down. That part literally takes me 10 minutes???? ALL this is not that hard and I won't do it any different. Dbltree took some pics of my set up, maybe he'll check this and post those pics?? I've done this about 12 times now, done the other ways, had tipped over blinds, non-sturdy stuff, trust me- don't mess around!
*ONLY DOWNSIDE to the way I do it - if you wanted to move the blind. BUT- I actually have moved them- either take blind off, cut platform off, re-cement at 4' shorter height now (because of cut off) OR just say, hey, I'll pull the blind down and spend another couple hundred on building new platform. Me and 2 bros made 2 platforms in 7 hours start to finish.
