I'd want to build a scale which can be "locked" in order to prevent weight from being pressed in it.

The scale and the weight are permanently fixed on a vehicle and I want to make sure it doesn't break under excessive force during travel.

What I have in mind is something like the schema below. Does it have a name?

Or are there other, more common ways to achieve this? I am looking.at something that can be done quickly (a screw would take too long and I'd need 4 of them.

If it matters, I need about a 5mm displacement, and a supported weight of 200kg

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  • 1
    $\begingroup$ probably cam . $\endgroup$
    – jsotola
    Commented Jan 1, 2022 at 6:01

1 Answer 1


Maybe I'm not understanding what you have in mind but your drawing looks really complicated with sliding rollers in captive grooves and such. I also imagine the lateral movement when weighing something is undesired. I would just try to shove something underneath.

Simple methods are vertical guide rails that can be pinned. Or a swinging beam with a radiused top or eccentric cam that can be flipped up and locked/pinned into place.

But in my opinion, your thought about screws is the best. By far the most secure and with the greatest leverage. Use one in the form of a screw jack and use a multi-start thread to make it faster. That will solve the speed issue. You'll need to find someone with a lathe to single-point thread you some, which means instead of screws you might as well get them to just make two big screw jacks with hand crank wheels, instead of four smaller, regular screws.

Or if you can't find someone with a lathe, then perhaps find multi-start/fast travel threaded rod or lead screws. Typically used for linear motion.

If your plate was being guided on vertical tight rails then you only need one screw jack if it is big and strong enough since the rails would eliminate tilting.


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