Dear @Karthik , Whether we experienced it ourselves, or had been conversing with other teams that did so, we feel as though PTC checks at Worlds drastically affected the performance of some middle school, high school, and college robots that competed in eliminations this year. According to the PTC A…

I think they should give us the option of running the stall test or showing them the PTC. In our bots, the motors are zip-tied to the mount for easy change and replacement. We could pop it off quickly and show the PTC and the lack of shorting. They could even apply the current right there at the PTC…

[image] TriDragon: We had a range of 0.25 seconds up to 6.2 seconds. With one never tripping. That’s a nightmare scenario. I wonder how the officials would handle that. Would you be DQed for something that is clearly not your fault?

[image] TriDragon: BTW, we applied a constant 3A to all of our motors, 60 of them, and then sorted by length of time to trip and an oscilloscope trace for good down to bad. We had a range of 0.25 seconds up to 6.2 seconds. With one never tripping. We took that one apart and found a short to the …

[image] Aponthis: That’s a nightmare scenario. I wonder how the officials would handle that. Would you be DQed for something that is clearly not your fault? No, I think the 6.2 would still be legitimate for them. They just want to see a trip in a reasonable amount of time. [image] _7682: …

[image] TriDragon: No, I think the 6.2 would still be legitimate for them. They just want to see a trip in a reasonable amount of time. I’m concerned with the PTC that never tripped at all.

I like the idea that was stated in the original post saying that tamper resistant methods could be put on motors after they pass. If a colored zip tie was used, it could be placed between the attachment points of the motor and around the top. I do not believe this would allow a motor to be tampere…

Please add us to this list, we were given this test 30 seconds before preforming our quarter final match and lost due to our robot preforming sluggisghly there after. I wouldn’t mind this so much if they tested the opposing alliance but they only tested ours putting us at a drastic disadvantage.

PTC checking needs to be done to prevent cheating, but the current system is flawed (obviously). We’ve all seen how badly motors run when the PTC trips, so what they are doing isn’t really good. I see a few possible solutions: PTC check right after a match. Have the fields set up so that they can…

One bit of good news is with the new smart motors coming out, theoretically PTC checks should soon be a thing of the past (although probably not for several years yet). Who knows if there will be some easy way to modify those motors to gain an advantage though

A Petition for Better Regulations on PTC Checks at Worlds

VEX V5 Robotics Competition VRC

jpearman April 30, 2017, 4:26pm 39

I’ve never seen as low as 0.25 seconds, sounds like the wrong part was installed.

For new forum members, a link to an old thread discussing the 4A PTC in the cortex.