Nice! Its always nice to hear about interesting projects on here. After a while, its a lot of the same. I know you said you already ordered the servos but, i strongly encourage you to try steppers for your next project. I will say though, the options online for mounting brackets are far better for servos and little to none for steppers so keep that in mind if you dont have a 3d printer.
If you dont mind, do you have any photos of your projects your willing to post?
I have several servos and steppers laying around and struggling to find things to do with them. I did give some of my cameras the ability to pan left/right which is great but, my ideas hit a brick wall after that.
I use steppers, but not for this kind of setup. When power goes off, I donât know stepper position and I should âhomeâ it with some switch or add encoder to setup. Also you need driver circuit⌠Often that noisy cheap servo with 3wires is just so easyâŚ
I donât have photos of my setup and itâs located under by enclosed bathtub, the main reason I didnât replace it yet.
The SG90 is the servo I would use. It has plenty of torque and your idea of a flexible coupling is a good one. If there are any model airplane shops near you, the SG90 is the Volkswagen of RC servos. Any place that has RC models will have the SG90. (If you see a model airplane or car, there is likely a couple of SG90âs in them. Buy ten. They are cheap online, and you wonât have to worry about damaging one. And they are fun to experiment with.
Controlling the servo through ESPHome is pretty straightforward.
then:
- servo.write:
id: servo_signal
level: 0%
I can send anything from 0% to 100% as fast or as slow as I want. You can have a Rotary Encoder on the ESP to control the volume.
Howâs this for an idea- put a sound level detector on the ESP (basically a microphone on the Analog input) and turn the volume up or down depending on the ambient sound level. Or adjust the volume from the engine RPM. (Wonât work on a sailboat).
The possibilities are limited strictly by your imagination.
Doesnât matter. The potentiometer will keep itâs position. When the servo powers up, its position depends on the PWM data. If the PWM is unchanged, the position will be the same.
Stepper motors generally donât have position feedback. You donât know where it is unless you start from a known position. Yes, they are more precise, but do you really need half of one-degree precision?
Well you can save and restore the position just like with a servo. As long as its not moving at the moment power goes out, the position can be saved.
Also true about a driver but with the exception of the little bity sg90 servo, you would need a larger PSU for any other servo because 6-7v is the next size up. Not trying to argue, just saying. Its your deal, do it how you see fit.
I got these for a project a while back. Your project made me think of using a tensioned belt around the knob and then offsetting the stepper out of the way⌠idk thats where my mind goes sometimesâŚ
@stevemann I have ordered 6 SG 90 9G with 180 and 6 with 360 (180+180) movement, so then I will try the Volkswagen, thanks! And thanks for the tips on usage too!
Mandal, in the extreme south of Norway. Or rather on Norwayâs southern tip. Ten minutes in my boat, and the closest country ahead of it will be Denmark.
In my specific case itâs almost always moving and I also have blackouts frequentlyâŚ
The next step up from sg90 is still still ok with 5V psu (MG996, Stall torque: 9.4kg/cm (4.8v), Stall current draw 1400mA)).
Nice belt pulleys you have, plenty of times needed those (small size) and never had on handsâŚ
Oh ya, i forgot about those. For what its worth, ive had horrible experiences with those. Theyd be defective, not operational, stripped gears, some were supposed to be 180 deg and the internal pot wouldnt stop them so theyd strip gears and become continuous rotation servos on the first use⌠Maybe it was the vendor selling junk, idk but my experience was a nightmare.
Sorry for your experiences. There are so many variants, plastic geared, metal geared, MG995, MG996, MG996R, different turn degrees etc. Hit and miss to have good ones.
The one in your link is really nice, strong and silent, I used it once. But you need 6-8V 3A supply, so itâs not so âpracticalâ for prototypingâŚ
Ya, it sucked. You can get mg995 4 packs for pretty cheap. I get where your coming from with the <5v power requirements but, IMO its just a matter of the project and your willingness to improvise. Dev boards have 12/24v regulators now, there are very small buck converters available and many projects ive done, its not unusual to need 5v, 12v, and 110vAC so, it all depends on what someone is making.
Of course, but I try my best not to accumulate components in my drawers, so 7V3A bucks are not always on hands while 5V2A supplies I cand find in every corner of my house. I have one 1200W programmable supply for âwhateverâ situations, but often itâs not the most practical choice. Call me lazy!
I need to get on your âno clutterâ program. I was just going through some of it today and i have organzers of esp boards, sensors, buttons, through hole components, transformers, multiple raspberry piâs⌠thats several years worth but, its getting ridiculous. I just know as soon as i get rid of a bunch of it, ill be back online within a month buying this or that in a 5 pack and only need 1!
Or like me: When I downzised from a big house when the last of our kids moved out, I threw out a bunch of old stuff that I would ânever everâ use again. I have bought a bit too many of those again now, six years later.
Nobody knows what I have inside my 3 meters wide closet in my work room. If I die, they think Iâm some fucking freak. And I do my best every day to not accumulate stuff. But 1 board cost $5, 5 boards cost $7⌠What can you doâŚ
I use some of the 20-25kg metal gear servos in my props, but the SG90s should be good for the volume control that @Mastiff is using. In fact, he may prefer theplastic gears in an ocean environment.
I didnât even know solid state potentiometers excisted. But finding one that works well with audio may be a hit and miss thing, not to mention that the price for three of those probably will be rather high.
I stand corrected. Maybe I should try those next time, if they are suitable for audio. Do you know that? But they might still be a problem because I fought like heck to get all sources of noise away from the signal path (and that was a fight in an aluminium boat full of electronics!), and thatâs why I wanted to use passive volume controls driven by a separate motor. That way thereâs nothing that can come in and create noise. I actually had to use an USB sound card to get the audio out signal from the Pi in optical SPDIF and then use a headset amp to convert that back to line level. That took care of the noise on the line both on the boat and in the car (elecrtical car, so not much less that can make noise there).
And thanks for the tips on usage too!