View attachment 138443
Here’s confirmation of the weight at 253g with a standard strobe configuration of one light. I use a 3D printed mount for even better visibility which adds even more to the TO weight.
My scale is a bit more accurate, and I check it against one that is accurate down to the thousandths. One thing I think you may be missing in your image is the SD card. I checked, most of mine weigh right at .248 to .268 g not that a 1/4 g would even register on your scale.
And the argument about a couple grams. Yes, an officer can pull you over and give you a ticket for 1MPH over, but they don't. There is discretion, and likely nothing will happen if you have a 253g drone and no incidents. However it is NOT LEGAL. doing 46 in a 45 is not legal, even if you do not know what the speed limit is. So, that's my point, and the OP coming back and saying that that he/she will be legally flying their sub-250g drone when they know for a fact it is greater than 250g and is not legal. You may never get in trouble for it, but it isn't legal.
So say, you decided that it was close enough and you are going to roll the dice, that's fine, but don't LIE and say it is LEGAL to fly a 253g drone under sub250g rules. It isn't. If you don't believe me, email the FAA helpdesk and ask them if you have a drone that says <250g on it, and you add modification that makes it more than 250g, can you still fly it unregistered. I would bet $1000 they say you have to register it.
And good to know you are an aviation engineer to know exactly how 3 grams on a 238 gram drone will effect it in all circumstances. Actually how much a 5% change in weight would be, since it is 14g on a 238g drone as designed.
I concur that no one is running around with a scale checking every drone before take off. Of course thinking like the OP here will make that a law too, but it isn't for now and no one is checking, but when something does happen, and the FAA finds you were flying illegally and overweight in the first place, your lawyer is going to have a heck of a time trying to convince the judge that you were not negligent and that even though you KNEW that drone was 250+ and that the law based on your 107 cert, you know that was take off weight, that you weren't trying to circumvent the law. I doubt a judge will buy it. So when something happens, you are screwed.
Now, if you are 100% compliant, sub 250g, registered if not, and a Medivac heli hits your drone and there was nothing you could do, you will likely have no fault and no legal issues. But when your 253g unregistered drone hits a medivac heli, you will get fined. If they find enough pieces of it that is...
Final thing, you said you have a 107 Cert as well. It is a lot more likely that a strictly hobby flier gets that wrong, that the base unit is the weight they check, instead of a part 107 (and in court the FAA will bring it up) that you should know because you are fully certified and it was on the test. That it is TAKE OFF weight, not how much it weighs in your basement with no battery in it.