I’ve seen the zip tie that supports the hanging tube snap during a tournament when a robot went to hang, and I know in our own practices we’ve had the zip ties snap on the hanging tubes multiple times, too. It seems that there is a lot of stress put on the zip ties because of the angle that the zip ties must go through the hole, plus the hole itself creates a stress concentration even if you debur it, etc.
Has anyone else noticed their zip ties snapping on a regular basis? I’m wondering if we should use something stronger, like a piece of steel cable and beg Vex to allow that at the tournaments.
I may be misunderstanding you but we have the plastic PVC pipe going through the corner bracket and it’s held by a screw going through the hole. The zip ties merely to hold the bottom of the pipe to the corner at the floor so all of the pressure should be on the corner plate.
Interesting. We haven’t seen that at the school practice fields, and hanging happens a lot on some of them. I haven’t noticed it at competitions, or heard any of the VEXers complain about it. They have complained about the hanging poles not being set up correctly at some tournaments, with the zip ties not being tightened. I’ve seen that twice personally, but no breaking.
Yes, that’s the correct way to set it up, but if the zip tie breaks, then the corner bracket acts as a pivot and, with any force applied to the top of the hanging tube, the tube will tilt over.
It might just be a bad local source of zip ties, too. I just want to be sure this doesn’t happen at our State tournaments.
As long as I have been reading your posts you don’t seem like someone that would have an improperly installed field.
I will say that we have put enormous amounts of stress on our tubes without issue. As long as the posts are secured in the corner the field walls should absorb most of the stress and weight.
One thought may be to use two sets of zip ties in a high and low hole set of the field
I think that’s true so long as the robots are pulling on the top of post toward the direction of the field. The breaking seems to happen when the kids drive up to the post and their hook system bangs against the top of the post, pushing the top of the post away from the field. That’s when the post acts like a lever and stresses the zip tie. I think the zip ties have been breaking where they pass through the hole in the field’s metal frame, whose edge acts like a cutter.
The zip ties that came with this years game kit were garbage, they snapped first time we tried to hang. Higher quality zip ties have held up well though. Another idea is to use the corner bracket on the bottom and put 2 bolts/nylocks on it that the pipe will hit when pivoted instead of stressing the zip tie. I couldn’t find instructions on actually mounting the pipe, so I did that to one of ours, since otherwise the pipe will dig into the foam tiles.
I want to emphasize, poor field kit instructions. There were foam squares that came too, I didn’t know what they were for either, or what screw to use on that hole in the pipe. Unless someone can direct me to that page in the manual where those parts are used.
That was the only page that referenced anything when we were building our field. I just felt like I had a lot of spare parts left over, so I just used the only spare screw that fit the hole in the pipe, which was a countersunk screw even though it looks like a Pan head in the manual. That manual still doesn’t reference the 8 adhesive foam squares that came with the kit.
TL;DR, I can understand why almost all the competitions we went to before Christmas had delays because the fields were built wrong. And don’t use the zip ties that came with the poles.
My best guess would be that they’re meant to go on the bottoms of the towers if the towers get mounted to the floor. But I’m honestly not sure; I don’t remember getting any of those in our kit.
