Crib

Not sure if I'm in right forum for this. If I'm not I apologize.

I'm designing a crib. The internal mattress support is seperated from the external frame and will be raised and lowered like a sit-stand desk. I can't just use a sit-stand desk because I need it to be as low as 10" from the ground.

I've learned that I can use feedback linear actuators and an Arduino control board in order to avoid having to code (I'm a physio, not a tech guy). However I'm not sure which control board to use. Also I want it to be raised and lowered by a foot pedal/pad/button...

Any thoughts?

Kyle

What you describe isn't going to avoid coding, sorry.

But physiotherapy is a technical subject, isn't it? You need deep understanding of the mechanics of the human body, the ability to analyse and diagnose problems and develop solutions to fix them. So maybe you are a tech guy too?

Given enough time I can probably figure it out. So far all I know is the people at Firgelli's stated with an arduino control board and the feedback actuators I could avoid it. I don't need pre-defined heights. Just a simple raise and lower.

Thank you though.

For the choice of Arduino board, it sounds like any basic one will be fine. I would recommend a Nano.

What we really need is a link to the model or models of linear actuators you are considering.

What is "Firgelli's" ?

Gotcha.

Here it is.

the 12 stroke, 200lb one.

Firgelli's is just the name of a company that sell's actuators near where I live.

This is how you post a link on the forum: Feedback Rod Linear Actuator - Firgelli Automations. Read the forum guide in the sticky post for other useful tips.

The Arduino can control these actuators, no problem. The easiest way will be to use a pair of relays per actuator. An Arduino pin will be required for each relay.

What I don't see any need for is the feedback feature. From your description, a less expensive equivalent of the actuator without the feedback feature is all you need. Most actuators have built-in limit switches, so they automatically switch off their motors at either limit of movement, and no feedback is needed to prevent exceeding those limits, and you don't need feedback for positioning.

Now the biggest news: I don't see the need for an Arduino, relays or coding. The actuator can be controlled by a couple of dp-dt (single-pole, double-throw) pushbuttons or a dp-dt (double-pole, double-throw) switch. We can show you how to wire them to the actuator.

Wow Thank you very much.

Hi,
Most actuator manufacturers, and Firgelli is one I think, have purpose built controllers to do this job.

You might be best to contact/email them and ask if they have a solution to your problem.
They have controllers that control two or more actuators at once and have various interface methods.

If you want to use an Arduino, then you need to specify actuators with position feedback and force output to to cope with the load of the crib and payload.
Also power drive units needed to interface the actuator with the digital Arduino output.

There are power supply considerations as well.
If I was you I would be consulting the experts to see what is available and what you need.

Tom... :slight_smile:

Agree with TomGeorge. This doesn't require an Arduino, just a switching mechanism. I have used the Firgelli (rotary) actuators and they are good quality for the money.

However, there are safety concerns that you should think of. There are also regulations regarding any mechanism that lifts/lowers a human that I'm sure you're already aware of. At a minimum I would have an Emergency-Stop switch.

It was firgelli's that told me I would need the arduino board, they stated they don't supply control boards and so suggested Arduino. If I don't that would be great. Mind you it was the sales guy that told me.

So just a pair of actuators with a switch with an emergency stop?

So if feedback actuators aren't needed. I guess I would just use these ones

the 18" 200lb ones

I was going to suggest you use Firgelli's -R versions which act like RC servos and afaik can be controlled in Arduinos using the servo library.

(Side note: I thought Firgelli was taken over a few years ago and changed their name?)

Hmm I can't seem to find the R versions

kjdstanton:
Hmm I can't seem to find the R versions

Nor can I now, perhaps their model designations have changed. I'll see if I can find an old link somewhere.

The -R ones are/were just 3-wire ones like a hobby servo and with the servo library the idea was just to use servo.write().

Ah here's a link to Acutronix -R version.

I thought Acutronix was Firgelli's new name. Anyhoo, have a look at that one...