Our testing tonight showed a couple dozen removal cycles makes the panel almost fall off (when facing down) under its own weight. It appears that some of the loops break every detachment, because the damage is progressive. This is going to be a problem I think.
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Thanks for sharing! Hopefully FIRST will determine and share a method that they will use to determine when they replace disc’s. There’s probably going to be a lot of velcro mechanisms out there that deteriorate how well the panel sticks to the hatches
I was discussing this with my teammate and I think it may be less of a problem than we think, as panels will be rotated randomly and be on either side, at most, there will be 2 attach/detach of the velcro per cycle of the hatch panel (bot holding it and it being attached to the ports) as long as your bot only connects with a few inches of velcro on either side, I think it won’t be such a big deal for practice, maybe different for competitions though?
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Some math:
Circumference = 3.14 *19 * Two Side = 108 inch of velcro
Amount of loop velcro (loop) in contact with Vecro(hook) on wall, 8"
So Percent of Velcro used per attachment 8/108 or 6.7%
Assume 50% of Hatches will be used on average for a match during the season.
At least in Michigan 82 Qualification matches and max of 21 playoff matches for a total of 103 matches.
So a part of Vecro on a hatch usage per weekend 3.5 (6.7%*50%*103)
Do 6 weeks or tournaments a hatch would see 3.5 *6 attach/detaches = 21 uses
So if someone can test a patch of the hatch to see how it does in 21 uses and if it still functions properly that should let us know if it is likely to get through the season without issue.
On the extream assume 100% usage per match and through championships then the number of attaches/detaches would go to 7 usages per week for say 10 weeks (round up for State and worlds having potentially more matches), so it can survive 70 then will be a non-issue.
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Does your 8 inches account for both left and ride strop of hook and loop tape on the hatch? You also should add something like 15-20% for practice matches and referee demonstration/volunteers playing around.
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Hopefully FIRST realizes their error and switches to flex tape.
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Hopefully FIRST realizes their error and switches to flex tape.
“I CUT THIS HATCH IN HALF!!”
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Can you give more details on the hook tape used that caused the damage & whether it matches any information provided by FIRST about the field hook tape?
We’ve got a few different styles at our shop, and they all behave very differently from each other on the panel and on the carpet.
When we say “damaged” is that visual damage? Does it still function, or are we talking damage to the function of holding on?
The 8" is suppose to represent the contact on both side, just a guess from memory so if someone has a more accurate number please provide.
Updating for 10% on low end and 20% high end still the question in my mind the question is if a patch on the hatch Velcro can withstand about 23 uses not likely a problem if can survive 84 uses definitely not a problem.
(By the way, my expectation is the good people at FIRST HQ are smart and already did some test like this and it passed the expected season full of use, or they have a plan. I remember going to worlds for stronghold and we had all new balls)
The “hook tape” is nothing special. It’s the Velcro industrial style (not the velcro “extreme” style) here: https://www.homedepot.ca/en/home/p.velcro-industrial-strength-4-ft-x-2-in-tape.1000112416.html
It gets progressively less able to hold on to covers. After a couple dozen cycles, with the cover hanging horizontally downwards from the hook tape, a slight acceleration is enough to detach it. It’s stronger when the cover is vertical and the velcro is loaded in “shear”.
I think you all are underestimating cycles. There will be teams using hook tape on the robot to pick up covers, and they will be dropping, and picking up covers repeatedly. And heaven help the covers when they meet a team using a hook-tape covered powered roller for a floor pickup.
They addressed it this afternoon on the Q&A: FIRST FRC Q&A System
Q&A Entry 5
HATCH PANELS will be replaced when the loop tape is no longer suitable for gameplay (i.e. the HATCH PANEL will not remain attached to the HATCH when a reasonable amount of force is applied by a CARGO attempting to exit the BAY). Hook tape on the ROCKET and CARGO SHIP will be replaced if they become degraded to the point that HATCH PANELS can no longer meet similar criteria.
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Just need to find that reasonably astute observer!
Well, a non-complete answer is still an answer I guess. It’d be nice if hatch panels were replaced before they fail during a match - which is how I currently read the answer.
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I thought the hook Velcro on the cargo ship was 5 1/2 inches per side of opening.
They can always add a couple of pegs below the hatches to catch them if they slide down and they will still prevent the cargo from falling out
Here’s a model I put together on the hatch cover loop tape.