Flite Test | Servos 101
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- เผยแพร่เมื่อ 6 พ.ค. 2024
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Get your pencil and notepad ready. Class is in session!
Here is an overview of everything you'd want to know about servos, and more!
New to R/C? - flitetest.com/articles/beginne...
Good job Peter! I learned more about servos in 20 mins than I have in 2 years.
Very cool episode. In 25 years I have only taken apart a servo 3 times and each time I frown and toss it in the garbage, this helps me make sense of these wonderful little devices. Thank you for this video!
Thank you for this awesome instructional video. The Q&A style presentation was great, basically asking the same questions I was interested in asking myself!
Peter did not go too deeply into any one topic and covered a great range of knowledge. I especially appreciated the testing jigs for torque, speed, and browning out.
one of the best episodes I've seen (I like breaking stuff down and figuring out how it works).
Little Bits are awesome, my 5 year old daughter received a set last year for Christmas and loves them.
So glad you guys keep putting out videos. You're such a help to people just starting to get into the hobby, keep up the good work, and get Peter to do more in-depth technical walkthroughs, it's awesome!
“Foot-pounds, inch-pounds, inch-ounces, newton-decameters, etc...”
Every question I had as a beginner to understanding what a servo is, was asked and answered in that episode!! Great work!!!!
All your vids are great and this type of video has its special place. From a techy perspective, one of the best - answers many many questions quickly. Reviews of multicopter controller boards and other components would be appreciated! Thanks, guys.
Thanks for the fantastic video! I've learned a lot from you two. I'm just getting into the hobby now and every little bit helps. You've inspired me put together a better power supply setup that will prevent the servos from browning out the receiver power in the event of low battery and/or overload. Cheers!
Excellent video Peter and Eric. Lots of information to absorb and basically love what you guys do!
Great overview - Thanks for taking so much time to put such a comprehensive tutorial together.
Wow, awesome video. Super informative. I honestly think this is one of the best educational videos you have ever done. Eric made it that much more engaging by being genuinely curious. Really well done. Thanks for that.
Thank you guys. This is the only useful servo explanatory video I've seen - and I've seen scores of them. You have answered all my questions. Thank you!
Make more videos! I am so impressed. Never have I ever come across a video that actually explained everything that I had questions about. Very thorough...just the way I like it.
Great stuff! Thanks for the knowledge Peter! I have been flying for a few years now and never knew this stuff.
Very good information on servos. I love how you bring the science out of these. Great visuals.
I see that the analog servos could possibly be the reason for aerolon wing "flutter" I'll switch to digital now.
Can you guys explain servo chatter. Ive seen intermittent times where even new servos would humm or chatter on their own while the transmitter control is completely still. What may be causing this to some of my analog new servos?
Enjoyed this video very much. Thank you for the information.
As someone JUST getting into this, THANK YOU for the tutorials!
Eric and Peter are getting really good, they work really well together.
At the moment, best presenter duo in the channel.
Actually the torque is the same, no matter the length of the servo arm. It's the FORCE applied that changes. The torque is a fixed number for the servo.
Tiago de Pádua Correct.
Torque = force * lever length.
Okay, technically the lever length is called "moment arm" or something like that, but I'm keeping it simple so non-nerds can understand it better.
44R0Ndin
Let's try working that formula with actual numbers.
force * lever length = torque
5 *10 = 50
5 * 20 = 100
Looks like torque changes when you change the lever length even though the force stayed consistent.
SuperLoopholes
Exactly as I expected.
Of course, if you hold torque constant in the equation, shorter lever arms apply more force.
torque = force * lever length
2 oz-in = 0.5 oz, 4 inch arm.
2 oz-in = 1 oz, 2 inch arm.
2 oz-in = 2 oz, 1 inch arm
Mechanical advantage. It's all about ratios.
This is reminding me of ohm's law. Which makes sense because it's a similar 3 variable formula.
SuperLoopholes That would be correct if You'd be turning a servo shaft by constant force applied to the lever. Torque would change.
In our case servo produces some torque on a shaft, regardless of how long the lever is. And the longer the lever the less force You have on a pushrod and more it travels.
Thank you FT Crew for the digital vs analog explanation...this very insightful as I am prepping to build my first foam board plane. Thanks again.
Excellent video and very informative. I've been flying for some time now and this video helped me understand more about servos and thier operation. I love Peters graphs and displays. I'm a visual learner and that helps me out tremendously. Great video fellas!
Great video, guys! I really liked it.
Could you do a similar video on motors? Maybe explain what the numbers mean, how the sizes are specified, brushed vs. brushless, efficiency, KV, and so on.
It would be really informative!
As always, keep up the good work!
Learnt from experience to always pay extra and get metal gear servos, that way they won't strip and when move up you can just take all your electronics with you.
Best servos for acro I've used so far are the Corona 929MG. Excellent upgrade just to replace the standard 9g servos most planes seem to use these days are dirt cheap ($5.50 per unit from Hobby King).
What about using a capacitor for avoiding brown-outs or at least to help?
When is the shinden being released?! Im so hyped to get one!
Good Job Peter!! you really are an asset to the flite test team!!
oh my god, i have been doing this for 15 years, and man, THIS is the video i have been waiting for!! seriously, what an amazing job you guys did on this! please do a servos 102, 201, 301, i will watch all of them :) love this!
Extremely educational and illustrative demos.
Many thanks.
Love these videos! You guys do a great job on informing us on even the smallest detail and sometime that's exactly what I'm looking for, other channels do a good job but not exactly like you guys! Thank you for you guys taking your time to inform us. I use rc buggies/truggies, but the electronics have the same principles as far as my knowledge 😂
Outstanding, glad you guys have done some more tech style videos like you used to do.
Very awesome video guys. You guys answered every question i've ever had about servos. Now i have some updating to do on all of my models. Thanks!
That was a fantastic tutorial - really clear and pitched just right. Thanks.
Not only informative but presented in a fun, entertaining manner
Fantastic video guys! Learned a lot of things I usually assumed. Some of my assumptions were correct but a lot of things you mentioned I never actually thought about. Thanks FliteTest!
Great video I learned a lot. What is the wire gauge (awg), I’ve herd anything from 20awg to 26awg? The 26 awg was on the hobby king website as extra wire for servo extension.
Wow, nice vid! I would love to see a video about motors where everything is explained. What mean 2206 etc?
Thank you, this clears lots of question up for me.
Peter seems like he was truly in his element in this episode. Awesome presentation!
Well done flitetest, very educational, entertaining and simple to understand. As a experienced pilot, i really enjoyed this video.
Keep on going guys !!!!
Man this video was amazing, thank you. Its always easy to pay the money to get the better SERVO's, but it is nice to know WHY it is worth spending the extra money. THANK YOU Flight Test Crew!
This Is One of The Most Informative Videos That Flite Test Has Produced & I Have Watched Nearly The Last 7 years Worth Totally! Soo Thanks & Keep Up The Great Jobs Guys!!!
Awesome:) At 13:30 with regards to servo speed. The rating is how long to move 60 degrees so LOWER is faster and usually better; not higher.
Rav Gupta lots of little bits of misinformation in this video. still really good for anyone with a cursory understanding of physics.
Great explaination of how servo's work. Thanks
Thank you so much for making this video I actually built a Tricopter and used a little 9 gram servo and it broke immediately and looked to the right midair did not end very well
Here's some basic Motors 101 for you:
There are many types of motors used in almost everything:
Brushed motors
Coreless motors
Induction motors
3-phase motors
Brushless motors
Synchronous motors
Permanent magnet motors
Stepper motors
Almost every motor has three parts: the stator, the rotor, and the commutator.
The stator is the magnet that does not rotate.
In a brushed motor, it is just a permanent magnet, as it is in a coreless or a permanent magnet motor.
In a brushless motor, an induction motor, a stepper motor, or a synchronous motor, it is a set of coils.
The rotor is the rotating element.
In coreless motors, the rotor is just a set of coils.
In an induction motor, it is the squirrel cage assembly.
In a brushed motor or a synchronous motor, it is a set of coils wound on laminated metal.
In a brushless motor, a stepper motor, or a permanent magnet motor, the rotor is a permanent magnet.
And finally, the commutator is responsible for the timing.
In a brushed motor and a coreless motor, the commutator is a brush.
In a brushless motor like that in a computer fan, the commutator uses hall effect sensors. In larger motors like those in drones and planes, the ESC relies on timing alone.
Induction motors have no commutator.
Synchronous motors use slip-rings to provide power to the rotor, but do not use a commutator for timing.
Stepper motors require a special controller and have no commutator.
You guys are awesome. I am ready to start playing with netduino, I will be doing servo projects. This episode helped so much...
The best show this year!
Outstanding. Accurate, clear, excellent interchange, please consider teaching as a future career.
11:30 Alright Torque is the Lever arm length times the Force of the thrust. T=LxF So for a lever arm 1" long and a Force of 100 oz you get T=1 in x 100 oz = 100 oz-in of torque.
Unlike what they say at 11:30 as the lever gets longer the torque doesn't change. The torque is the torque. However as the lever gets longer the force goes down. There is an inverse relationship between the lever length and the max force of the thrust. As one goes up the other goes down.
Fantastic. At the airfield I was asking some of the senior pilots some of these same questions. But they couldn't answer. Now I know. Great video.
Pete Always has awesome projects and knowledge👍🏻
New drinking game: take a shot every time they say “basically.”
This is precise tips and informations. Thank you for that!
Great video Guys. Well done Peter, very intuitive.
I liked this. It was more informative than most of the videos I've seen here.
ive been in the game for 3 years and learned a few things that have always bothered me from this video, thanks for your work guys =D
Great explanation - helped me a lot! And, I'm fairly sure one of the planes in the background is a JRC Models F-22 dual stunt quadcopter - are you in any hurry to have a look or feature those things? (I may have seen them in the flying aircraft carrier vid)
Danny Zhang Now I finally learned what these are. Thanks :). Yes, they had them in the helicarrier episode and a few others.
Great work guys I like to think I know my stuff but I learned a lot watching this.
ATB Malc
Excellent work guys. Please keep up the good work.
Great video guys. Very informative and really dig the props to help us understand.
Thanks guys.
So whats the deal with the Magnetic Induction Servo? You said that you'd get back to it but never did? I assume it works through halls affect?
Is it true that digital servos draw more power? If I'm using multiple servos (ailerons, rudder, elevator, pan, tilt, roll) for my fpv... Would I be better off using analog to try to prevent brown-outs? Or am I better off using digital with a stronger bec?
Eric & Peter A Really Nice Servo Test Video very Interesting & I learned about Servo's ! Thanks Dave !
Really liking this more technical style of video.
+flitetest the stator is the part that stays static (no movement) the rotor is the moving part
How would you go about upgrading an analog servo system to digital? I'm assuming that the controller board would need to be flashed to send the correct signal?
So basically you guys didn't get back to magentic induction servo?
My guess is that it uses a hall effect sensor to sense position rather than a potentiometer. This has the benefit of a longer lasting servo since hall effect sensors have no physical wear like potentiometers where there's a wiper arm skimming across a resistive surface. I also believe this to be true because Peter physical rotated the servo a few times in one direction where if it was a normal potentiometer it would only rotate to the endpoints of the pot.
Yet another great vid guys. Great failure-mode demonstrations. If somebody knows of an aerodynamics program that discusses forces on RC control surfaces, that would be great. That would solve that issue where you just look at "what the other guy is using." Better to actually calculate and know.
Not sure if this has been mentioned already, or if this is even correct, but i THINK the reason they move the servo 1 inch to measure the torque is because in the U.S. torque units are pounds per foot or 'foot pounds' etc so moving 1 inch is easy to convert to ft/lbs because it is 1/12 of a foot.... i'm just speculating haha i'm not totally sure.
-Colton
Amazing information, this was worth every single second.
i would have liked some info regarding the size of Servos. when choosing a servo based on physical size, are the dimenaions given on websites like hobbyking or banggood the hole to hole size, or the dimensions of the main casing?
tia
Very good information, Peter can explain it very good. thanks!
best informative video on servos Hands down!!!
Great info. Especially about the servo brownouts, I literally had no idea about this. I think I've experienced this on my fixed wing. What's the solution to stop that from happening?
***** You need to get a BEC that can handle more load. Peter was using a 1 A BEC in that ESC, if he had switched to something with 2.5 or 4 A it should have worked.
I read that a standard servo draws about 10 mA, stalled it draws about 200-250 mA and in normal flying 75-150 mA. Since he was moving them quite fast, it was probably more in the 200 mA area. This times 6 servos will result in 1200 mA - too much for the BEC, so it wasn't able to deliver enough power to the receiver.
The bad thing is that you won't notice it as long as it is in the "normal flying" zone with 100 mA, but if you do something crazy in the air, it will just shut down on you.
Balu Thanks, that's actually really helpful. Now I know what to look out for.
Great job guys, peter you are a clever dude, loved your flying drill LOL!
Hi guys. I was wondering if Josh Scott was coming back?
Will routing the power for the servo's from a separate BEC to bypass the receiver prevent risks of a brownout? I tried it once but I ended up frying my servos. Theoretically it should work right?
So how do you fix the cutoff of the receiver from too many servos? Better receiver BEC or something else?
Learned a lot and am away to check the sizing of my 6 servo speed controller :-)
This is great information. Very accurate and no bull.
I am learning. And your definitely HELPING. Thanks
2:00 Where can I get one of these? That would work great for a Sweep Wing system in an F-14 Tomcat or F-111 Aardvark.
f you were to use an old cheap two wire motor style servo for steering, could you use the two outside wires on the receiver to make this work? or am I deranged and polluted? Thanks
Can a servo use the electrical signal on a car's brake lights to flip up an airbrake ?
BTW, I mean a full size car.
I have seen some huge scale planes that require a lot of torque to move the flaps.
Thanks for any help.
Nice presentation! Thank you for the video.
Question
If I fly a plane that's 1-1.8lbs
What's the smallest servo that would work in a straight wing trainer.
It has 8 or 9 gram servos now.
I'm thinking of building a lighter scratch built Sailplane & wondered if 4,5 or 6 gram servos would be ok?
Man, I wish they made more informative videos like this nowadays
Thanks guys, this video really helped!
Fascinating introduction
What is the plane behind Peter, and is there a video about it? Almost looks like a Burt Rutan Long EZ. Except the verts. (It would awesome if you had a kit/plans for it).
Helo guys!
Can i saw your vtol guinea. It was beautiful! :D (I like the vtol planes) Can you make a ,,how to" video abaut this modification?
Can you do a video on the Dream-Flight Libbele dlg
That was a great vid! Thx
Little Bits are great to play with. We had a big box of them last year at Re:Publica in the Maker area and everyone was just creating stuff that made noise in some way or the other :). They are a bit pricey though.
you guys need to make the plane behind Peter available on the free build plans.
Fantastic and very helpful video. I watch all your videos but got so much info for me from this one... Thanks you..
Can you do a video on choosing the right motors? KV, Watts, etc.
What would be a formula you would use to find how much torque need at a certain airspeed?
very informative, peter if you see this please make a pun jet for the mico cargo, biplane?
Jack does anybody think its possible
Jack Scaling it down is going to be hard. I think foamboard might actually be too heavy of a material at that point, and the motor is also going to be a problem.
Of course, with enough money it's possible, but i don't think that they would work on it. The only material flite test has used is foamboard, and i do not think they will stray from it for the sake of consistency.
Jack The problem is, smaller the plane, higher the tolerances You have to meet for the plane to fly well. And for a foldable foamy the Pun Jet seems to be on the edge.The other point is, smaller the plane, the more agile it is. You would need a very good reflexes to control it. Or use an onboard stabilization. But the rule of thumb is, bigger plane flies better. Or is easier to fly, at least.
I have a plane that I am going to run flaps, that will make the plane have 6 servos 4 digital and 2 analog.
is there something I can do to keep from having my servos quite working?