I've been using two
Gibraltar GRS-350C for the past 4 years. My son plays Industrial, and I play Free Style everything for the past 50 years. Even got the wheels and replaced the rubber feet. The wheels have locks. The clamps need to be really tight. Never had any problems with this double rack
Gibraltar system as of yet. It takes quite a beating. Needed the wheels for cleaning the stage every so often.
The square rack type sounds quite interesting. Think I'll go to the store and check them out.
If it's a permanent fix that you guys are looking for, ever think of tack welding the clamps in place?
Sometimes DIY racks can become more costly and time consuming than just buying one.
If you've got the time and the dime, go for it and let me know how it turns out.
Please send me some pics of it and if your successful, don't forget to get a patent, some one may steal your ideas.