Latch Legality

Is this latch legal for FRC? Link to it:

R501 has the rules for solenoid legality

From the datasheet, I see that the solenoid can be run at 12V. It has a nominal output current of <500mA @ 12V, so less than 6W. You’ll need to show that the stroke of the actuator in the latch is less than 1", which I didn’t see from a quick look at the datasheet.

It actually looks more like a servo than an electrical solenoid? “Internal microprocessor control”

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I’m actually not sure about the rated power on that actuator. It claims a ‘typical’ value of <0.5A, but a ‘peak/stall’ current of 1A, both at 12V. R501 specifies rated input power of <=10W continuous duty: Does that mean that the solenoid must draw <= 0.833A when continuously powered, or that the device is only intended to withstand 10W of input power over a long period of time?

Regardless of the rated power question, you would also need to demonstrate that the solenoid inside has no more than an inch of travel. Since there is nothing like that on the datasheet, the only way I can see to prove that is to have an additional disassembled unit as demonstration.

This is all assuming that it does actually contain a solenoid actuator. It may actually not, if the “Electronic access with internal motor control” blurb is to be believed, in which case it is definitely not allowed.

As personal advice, I would not recommend you use this latch on your robot, even if it is determined to be a legal device. I’m not sure if you’ve gotten this for free or something, but you can get 12V drawer/cabinet locks for <$20, and nothing about this product screams that it is so much more useful to be worth its list price. Additionally, there may be many other ways to actually solve the design problem this was intended to. I, and I believe many others, would be happy to help with that if you want to explain more about what you are trying to do.

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I can’t tell from the description if it is legal or not. I did, however, find the manufacturer’s page for it: R4-EM-12-161 | Electronic Rotary Push-to-Close Latch, Auto Relock, Without Latch Status Microswitch, No Connector, M6 X 1.0, Steel Housing, Zinc Plate, Bright chromate | Southco

The “auto relock ” feature on it has me concerned. If it has internal logic controls that would allow it to move (relocking) after the robot has been disabled, then that would be a problem. Additionally, just looking at it I can’t tell how it would get wired up to be controlled by an approved device. There are a lot of wires shown in the picture!


Of the top of my head. It is not a “solenoid” (I would actually review the rule if I was inspecting) “servo” are descibed as such and powered of the 5 V bus with PWM control. Anything powered of 12V are motors and need to meet the motor rules.

Many servos move to a home position when disabled. By itself, that is not an dis qualifying feature.

My initial judgement is that it is not legal.

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Most (or all) of the people commenting in this thread are very experienced in FRC. Many have worked as Inspectors and even Lead Inspectors. They are all having difficulty saying this latch is definitely legal so it become very risky to use this in your design.

If you feel you must use this part, you should submit a question to the Q&A system and hope that it gives you a favourable answer or, even better, that the rules are amended to include this part. I am not optimistic that this happens though.

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