Actuator Question - Page 1
Forum section: electronics / general

author: bostonman
author_rank: Super Contributor
timestamp: April 02, 2024, 03:02:44 pm
content: I have a question regarding (I believe) actuators.Although I have little experience, mechanical actuators turn a gear (maybe a worm gear) to move the arm in and out whereas electrical uses a differential voltage (?) to move the arm.Does an actuator exist that remains neutral so it can be moved, and then applying a voltage locks it into place (then removing the voltage unlocks it again)?Searching online didn't seem to lead me to anything, so I'm curious if they exist and what they'd be called. Does anyone know and/or have experience using such an actuator?

author: RoGeorge
author_rank: Super Contributor
timestamp: April 02, 2024, 05:37:56 pm
content: Stepper motors move freely when unpowered, and stay at the last position when powered.

author: Benta
author_rank: Super Contributor
timestamp: April 02, 2024, 06:24:17 pm
content: It's called a linear motor.https://en.wikipedia.org/wiki/Linear_motor

author: thm_w
author_rank: Super Contributor
timestamp: April 02, 2024, 09:12:11 pm
content: It would help to draw a photo of what you are trying to achieve.Electric brakes exist,https://teknic.com/products/spring-applied-power-off-brakes/NEMA-23-brake/https://www.omc-stepperonline.com/dc-electromagnetic-brake-24v-2-0nm-283oz-in-for-nema-23-24-stepper-motor-swb-03But it sounds like you want the brake itself to move linearly, not axially? Search for linear brake.Probably not cheap.

author: bostonman
author_rank: Super Contributor
timestamp: April 03, 2024, 01:52:25 am
content: It's for a project I was thinking of.Ideally I'd like an actuator to pull in and out, but I might be able to use a stepper motor.

author: rteodor
author_rank: Frequent Contributor
timestamp: April 03, 2024, 02:17:56 am
content: Thermal actuators are linear but I can not say that they do exactly what you want or if they can be adapted to your needs.They are slow (some tens of seconds to minutes) but they have high force without mechanical complexity of reduction gear.You can find this type of actuators in automation of floor heating, bathroom ventilators or dishwashers. They work by heating wax but power consumption is (usually) small.For example: Eltek 100331.07.

author: thm_w
author_rank: Super Contributor
timestamp: April 03, 2024, 09:21:45 pm
content: Quote from: bostonman on April 03, 2024, 01:52:25 amYeah thats not enough info to go on.If its a light item use a solenoid, heavy item geared linear actuator.

author: bostonman
author_rank: Super Contributor
timestamp: April 07, 2024, 02:09:42 pm
content: It wouldn't be heavy at all.More on the idea of an arm (maybe 12" in length) made of light material to hold a meter lead on test points that contain high voltage; or are in an area that requires placing a hand too far down a unit while holding a meter probe.I'm not looking for alternative ideas, I wanted to tinker with such a setup and thought this would be a good opportunity to play around actuators/solenoids. The idea is to move the arm into place and apply a voltage to lock the actuators/solenoids so the arm doesn't move.