Hello,
Is there a micro servo that travels 180 degrees out of the box. I purchased a RB-Ada-200 a while back and it worked fine for that particular application swinging 120 degrees. Now I have a new project and would like to expand its travel from 120 to 180 degrees or find a 180 degree micro servo.
I noticed that while no power is applied I can move the horn 180 degrees but I cannot drive it to those limits. Is it possible to do it in software. I am using a romeo BLE controller.
Thanks
Most, though not all micro servos rotate ~180 degrees. A full 180 degree range would be a pulse from 500 to 2500.
That servo is limited to 120 degrees, and it’s one of only a few servos which have analog feedback. You cannot modify it in the software.
If you don’t need analog feedback, we offer many ~180 degree micro servos here:
robotshop.com/en/servo-motors.html
Many inexpensive ones here:
robotshop.com/en/misc-servo-en.html
Hello Mr Benson,
Thanks for the prompt reply. I did a search for micro servos just to narrow down the list. I the checked what specs there are for each one. I did not see any that say 180 degrees. I saw quite a few that listed the speed over a distance of 60 degrees which I took to mean 60 degrees in each direction or 120 degrees of travel. Probably a bad assumption on my part but lacking any other info I don’t know what else to think. How does one tell from the specs listed what the travel is. For example from the products page:
**
HS-82MG Metal Gear Micro Servo**
]Motor type: 3 Pole/:m]
]Bearing type: None/:m]
]Speed (4.8V/6.0V): 0.12sec / 0.10sec @ 60 deg./:m]
]Torque (4.8V/6.0V): 39 oz.-in. / 47 oz.-in./:m]
]Torque (4.8V/6.0V): 2.8 kg.-cm. / 3.4 kg.-cm./:m]
Is it just a give that 180 degrees is the norm and anything else will be indicated.
Thanks again for your help.
Art Smith
Unfortunately very few RC servo manufacturers provide the angle of travel, the only provide the fastest time it takes to travel 60 degrees. This does not mean the servo only rotates 120 degrees however.
The Hitec 82MG does travel ~180 degrees provided you can send a full 500-2500 pulse range.
Thanks you once again Mr. Benson,
Hi - is there any way of knowing which ones will have a full 180 degree rotation just by looking at the specs? If not (that’s annoying), could you recommend an inexpensive servo that can be controlled to rotate the full 180 degrees (not 170).
If not (that’s annoying)
Yes. Yes it is. Most don’t indicate the maximum rotation angle. However, the vast majority do seem to rotate 180 degrees provided they can get the full 500 to 2500us range, though I recall some traveling up to ~170ish degrees (so just less). I seem to recall most standard Hitec servos can do full range given the full signal. If you have a specific servo in mind, we can reach out to the manufacturer to confirm.
I’m very new to this tinkering thing so I really don’t know exactly the model I would need. Maybe you could point me in the right direction. In fact, I don’t know if I may even need a stepper instead. Happy to be pointed in the best direction.
All I’m looking to do is spin a motor a full 180 degrees when a button is pushed. And then when the button is pushed again, to spin the motor another full 180 degrees. I don’t care if it’s clockwise or counterclockwise, or if the first spin is CW and the second is CCW.
Also, I would just be spinning a circular 6" diameter piece of 3/4" plywood. So I think the torque would be pretty minimal.
Thank you for the help!!
Greg
There’s a lot to consider when choosing a type of actuator, then the specs. This might be useful:
Currently not aware of any wired RC servo or stepper options with a button input and specific 180 degree output for a button press. There are handheld and rotary options for RC servos, and the switch on a handheld remote control would have that effect, provided the min/max signal was set correctly.
Motor controllers:
https://www.robotshop.com/en/motor-controllers.html
RC servo motor controllers:
https://www.robotshop.com/en/servo-controllers.html
Thank you for the article. I will read it.
I am using a programmable Arduino control and standalone button. The Arduino will control the rotation of the servo. I just need a servo that can be controlled to rotate the full 180 degrees.
Perfect, then yes, you can program the functionality you seek and don’t need a separate RC servo controller. Just ensure the entire weight / load is not on the output of the servo’s spline.
Great. Thank you for all of your help so far.
So which Hitec servo(s) might you recommend?
Not sure about how fast you’ll rotate the part to know if inertia will be a problem (servos really don’t love to stop suddenly and whatever they rotate wants to keep rotating). Metal gears will last longer. If you’re really worried about rotation angle, and can program the actual pulse which the servo will receive, consider a quarter scale winch servo (plastic gears but can rotate up to 3.5 turns):
Another potentially better option with metal gears:
If you really think a standard sized servo is fine but want some torque and metal gears:
If you really think the wood is lightweight and won’t add any additional load this is “the standard” RC servo:
Wow thank you for all the suggestions. I am going to review this week and let you know if I have any questions.
Thanks!!
GR
@cbenson - thanks for all the help. I think the last HITEC HS-422 is probably the answer. BTW, do you work for robotshop.com?
Indeed. Happy to help.
@cbenson I’m wondering if you could give me any tips on the next part of my project. I got this servo with the intent of spinning a wooden dowel (1/2" diameter). I’m not entirely sure the best way to connect the servo to the dowel tho. The dowel is too small to just connect to the servo horns directly. Any recommendations?
Thanks in advance!!
GR
Can you provide a few clear photos of the parts and an idea (even holding by hand) of how / where you want it mounted?
Check out this link: Wooden beer bottle opener and candy dispenser V3 updated - YouTube
I am building the candy dispenser currently. I don’t have any clear photos of anything because I haven’t built that part yet. My thought was that behind the rotating wheel (inside the unit) would be a servo that simply rotates a dowel (that acts as the axis) that connects to that wheel. I attached a picture below from google.
So if you look at that image. Imagine the axis goes through a plywood sheet (with a hole), and connects to a servo.
You can drill a hole through the center to be able to access the screw which holds the horn in place (same diameter as the screw head to be as small as possible). You’d screw the horn into the wood from the rear (you can file down the small plastic “lip” around the horn so it’s flat).
