Hi Forum,
I need to move a device across 2 dimensions (up/down and forward/backward) so I thought using 2 linear actuators for this by connecting one actuator perpendicular to the end of the other one.
Is this possible?
I see that most of actuators have some holes on the end but not sure if this is for screwing stuff you want your actuator to interact with.
Also I want to control these from raspberry pi.
Is this possible also?
Guessing yes, but just to check.
Thanks in advance.
Hi!
Here are answers to your questions/comments:
In theory, this is possible. Of course, you will need to design a mechanical setup that makes this viable for your project. If you have the know-how (or like to learn), you may want to design it in CAD first to experiment with different ideas first.
Yes, that is what they are used for. You can use those mounting holes to use the force and motion produced by the linear actuator. Typically both holes are used to attach the linear actuator: one to a fixed position and the other to a moving object. In some (more complex) cases, both end points could be attached to moving objects!
This is certainly possible, but how you will achieve it depends on the actuator used and the control method you need. If the actuators are simple 2-wires (V+ & V-) with internal limit switches (stops at fully extended/fully retracted), then you can simply connect an H-Bridge to your linear actuator and power source and send a proper digital signal to control it from your RPi. There are plenty of hats to do this, such as RB-Cyt-218 which can control two motors (such as two linear actuators).
If you have a more advanced linear actuator with a internal controller interface, it may be possible to directly control it with I2C, PWM, UART, raw digital signals, etc. and even receive feedback, such as the current position of the actuator. In that case, you’ll need to read up on that specific actuator (datasheets/user manuals on the product page, under Useful Links) and see how to achieve the proper control signal with your RPi.
We hope this information helps you get started!
Sincerely,
Hi,
Thank you for quick response!
Also, since I am complete newbie with linear actuators, have a question that is maybe stupid.
My use case actually requires that for the most of the time actuators would be still and not moving, and then at certain moments I would activate them and extend/contract them.
I read somewhere that it is not good that linear actuators are still and not moving for a long time.
Is this true?
Can I use linear actuators in case where they would be not moving for the most of the time?
Hey,
Actually, most electric linear actuators use a setup with a lead screw. This means that the linear actuator is only using power actively when moving, not when at rest (at any position).
Therefore, they typically are perfect for applications where they move a bit and then do not move at all for a long time (ex: standing desks that can change height, LCD screen that moves in/out of a storage space/usable space, etc.). In practice, most lower cost linear actuators have strict duty cycles (the ratio of how long it can be moved versus rest). Usually this is around 20-30% (i.e.: move 20-30% of the time, rest for 80-70%!).
We also recommend that you look into using a track actuator for your project, as it may be easier to work with.
Sincerely,
