Newbie looking for help with motor/servo selection
05-09-2019, 05:19 PM
#1
Junior Member
Thread Starter
Join Date: May 2019
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Newbie looking for help with motor/servo selection
Greetings!
I am likely going to purchase the following chassis;
(JLB Racing Cheetah 21101 1/10 scale)
I am purchasing a chassis insted of a finished car because I will be adding a lot of custom features. I intend to create my own transmitter that will allow me to control the car remotely, from a laptop, as well as a custom battery using 2170 3.6v cells (~12000mAh) and a boost transformer to get 11.1V. I am a programmer, not an electrical engineer, so I would greatly appreciate some guidance in picking things like servos and motors, since I am so out of my element here. If you visit the website selling the chassis in the link above, they recommend some parts, however I believe the community here will offer better suggestions.
The power system recommended is a 3670 sensorless brushless motor and 120A ESC, 2650 KV
(I am sorry if this is confusing to any experts reading this, I am not quite sure what any of that means.)
As for the servo, I think this is mostly for steering? Therefore it does not matter nearly as much as the motor, and I would be open to pretty much anything cheap yet effective. I likely won't be too rough with it, i can't see myself needing a waterproof motor in fact, so if there is money to be saved, i am all ears.
I appreciate any and all suggestions
Will
I am likely going to purchase the following chassis;
(JLB Racing Cheetah 21101 1/10 scale)
I am purchasing a chassis insted of a finished car because I will be adding a lot of custom features. I intend to create my own transmitter that will allow me to control the car remotely, from a laptop, as well as a custom battery using 2170 3.6v cells (~12000mAh) and a boost transformer to get 11.1V. I am a programmer, not an electrical engineer, so I would greatly appreciate some guidance in picking things like servos and motors, since I am so out of my element here. If you visit the website selling the chassis in the link above, they recommend some parts, however I believe the community here will offer better suggestions.
The power system recommended is a 3670 sensorless brushless motor and 120A ESC, 2650 KV
(I am sorry if this is confusing to any experts reading this, I am not quite sure what any of that means.)
As for the servo, I think this is mostly for steering? Therefore it does not matter nearly as much as the motor, and I would be open to pretty much anything cheap yet effective. I likely won't be too rough with it, i can't see myself needing a waterproof motor in fact, so if there is money to be saved, i am all ears.
I appreciate any and all suggestions
Will
05-12-2019, 05:19 AM
#2
Welcome to RCU.
I'd be buying something like a GoolRC 3670, or simular blue/red smooth canned motor for $25. If the Cheetah was going to be my only RC, I'd want a reliable ESC...something like a Hobbywing EZRun Max10 SCT, or EZRun WP-SC8 speed control that is rated for 120 amps would be a great choice. Buying a super low budget ESC is very "hit or miss" on quality IMO. I'm not sure on the Kv you would want, but a 2650Kv, combined with a 3S LiPo, sounds about right. I know I wouldn't need more motor than a 2650Kv running off a 3S pack. That's currently what I'm running in my 1/8 scale buggy. YMMV on the Cheetah.
There are tons of choices when it comes to servos at various price points. For a RC platform with larger tires to turn, you will want a good strong servo with metal gears. I would recommend a servo with at least 200 oz-in (15 kg-cm) of torque. A moderately priced Power HD WP-23KG should be plenty of muscle with titanium and steel gears (not like some metal gear servos that use aluminum/brass). I only mentioned that Power HD servo because it has replacement gears available for it, should you need them.
Good luck.
Some good JLB Cheetah threads on RC Groups...https://www.rcgroups.com/off-road-cars-48/
I'd be buying something like a GoolRC 3670, or simular blue/red smooth canned motor for $25. If the Cheetah was going to be my only RC, I'd want a reliable ESC...something like a Hobbywing EZRun Max10 SCT, or EZRun WP-SC8 speed control that is rated for 120 amps would be a great choice. Buying a super low budget ESC is very "hit or miss" on quality IMO. I'm not sure on the Kv you would want, but a 2650Kv, combined with a 3S LiPo, sounds about right. I know I wouldn't need more motor than a 2650Kv running off a 3S pack. That's currently what I'm running in my 1/8 scale buggy. YMMV on the Cheetah.
There are tons of choices when it comes to servos at various price points. For a RC platform with larger tires to turn, you will want a good strong servo with metal gears. I would recommend a servo with at least 200 oz-in (15 kg-cm) of torque. A moderately priced Power HD WP-23KG should be plenty of muscle with titanium and steel gears (not like some metal gear servos that use aluminum/brass). I only mentioned that Power HD servo because it has replacement gears available for it, should you need them.
Good luck.
Some good JLB Cheetah threads on RC Groups...https://www.rcgroups.com/off-road-cars-48/
05-24-2020, 02:18 PM
#4
Kind of a funny thought, but maybe you want to consider something with very strong torque in your build. The reason being is that if you're controlling with your laptop (which is both very odd but totally cool), you're most likely operating it from a further distance than a normal transmitter. If that's the case, you won't be able to retrieve it easily which means you'll want some way to right itself if it ever goes upside down.
How is that possible you say? Well, the power your generating that would need a 120amp ESC may be able to right itself. Basically throttle forward and backward and time it correctly and it just might be able to flip itself back over. That's actually a feature on some of the Traxxas models. If yours ends up being able to pull that off, that'd be pretty cool. Looking forward to your build. Don't be a stranger. Keep us informed. Curious minds are watching.
How is that possible you say? Well, the power your generating that would need a 120amp ESC may be able to right itself. Basically throttle forward and backward and time it correctly and it just might be able to flip itself back over. That's actually a feature on some of the Traxxas models. If yours ends up being able to pull that off, that'd be pretty cool. Looking forward to your build. Don't be a stranger. Keep us informed. Curious minds are watching.
