# How to design 3:1 pulley/belt system for a UGV **URL:** \ **Category:** Motors, Mechanics, Power and CNC\ **Created:** [September 19, 2026, 11:00am UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219 "2026-09-19T11:00:07Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 11:00am UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/1 "2026-09-19T11:00:07Z")
Hi, I want to build the exact robot like this one: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/8/8/0/8802ae8deec3776dec11e5f8809e0d988b2cbccc.jpeg) I bought most of the electronics: 1. Motor: 12V 960rpm motors 2. Wheels: 100mm wheels 3. ESCs: 2x 5A Dual Way Bidirectional Brushed ESC 4. Controller: Arduino nano 5. Battery: 6s2p li-ion custom pack 6. Remote: Radiomaster Pocket ELRS with ELRS receiver 7. Chassis: Haven't done the chassis yet, in planning stage. But the issue now is that I need to design the drivetrain system to buy the mechnical parts; like, pulleys, belt, bearings and the carden. My first thought of the drivetrain was to use direct motor to wheel, but with some chatting with ChatGPT, it convinced me to use 2 motors and pulley/belt system. ChatGPT idea is to use 3 pulleys, one 16t in the middle which is connected to the motor and two 48t connected to the wheels, but the problem now is how to do that ? I aksed different AIs about this but they provided me with something that can't be done in real life, this one was done by Gemini: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/f/3/3/f3335ed3763ed8b2edb6f766baa5300db6296e66.jpeg) How that should work ? ---
**Author:** ![PerryBebbington](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/perrybebbington/32/238766_2.png) [@PerryBebbington](https://forum.arduino.cc/u/PerryBebbington)\ **Post date:** [September 19, 2026, 12:09pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/2 "2026-09-19T12:09:00Z")
@wolfrose , I moved your topic to an appropriate forum category . In the future, when creating a topic please take some time to pick the [forum category](https://forum.arduino.cc/categories) that best suits the subject of your topic. There is an " **About the \_\_\_\_\_ category**" topic at the top of each category that explains its purpose. This is an important part of responsible forum usage, as explained in [the " **How to get the best out of this forum**" guide](https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum/679966). The guide contains a lot of other useful information. Please read it. Thanks in advance for your cooperation. ---
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 12:32pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/3 "2026-09-19T12:32:41Z")
> [@PerryBebbington](#): > > category I think I picked the right category, it said "Motor, Mechanics, Power and CNC" which fit right into my topic. My topic about motors and mechanics. ---
**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\ **Post date:** [September 19, 2026, 12:33pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/4 "2026-09-19T12:33:02Z")
> [@wolfrose](#): > > How that should work ? No how. But if you name _left and right_ as _front and rear_ it makes more sense. Quite much work compared to direct motor to wheel . ---
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 12:45pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/5 "2026-09-19T12:45:29Z")
It shouldn't be that hard after I figure out the right pulley/belt system to install. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [September 19, 2026, 1:05pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/6 "2026-09-19T13:05:57Z")
Take a look at this place [https://sdp-si.com/products/](https://sdp-si.com/products/) ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [September 19, 2026, 1:16pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/7 "2026-09-19T13:16:17Z")
> [@wolfrose](#): > > How that should work ? Ask AI? Do you know, "AI" will churn out infinite answers, without a microsecond of original thought? It finds all the projects according to your input, statistically analyzes them, then cobbles together a guess. > [@wolfrose](#): > > provided me with something that can't be done in real life We know. It doesn't. Use what you know. Evaluate. Test. Stop asking AI. It will never help unless you tell it what to do. ---
**Author:** ![tigger](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tigger/32/1104210_2.png) [@tigger](https://forum.arduino.cc/u/tigger)\ **Post date:** [September 19, 2026, 2:36pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/8 "2026-09-19T14:36:35Z")
As shown, it's going to operate like tank tracks. Quite good for straight lines, steer by slewing. Independent motors, one per wheel, give you a lot more control. ---
**Author:** ![PerryBebbington](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/perrybebbington/32/238766_2.png) [@PerryBebbington](https://forum.arduino.cc/u/PerryBebbington)\ **Post date:** [September 19, 2026, 2:40pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/9 "2026-09-19T14:40:54Z")
Hello @wolfrose , That's where it is now, this is where I moved it to. I moved it from [Suggestions for the Arduino Project - Arduino Forum](https://forum.arduino.cc/c/community/suggestions-for-the-arduino-project/37) ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 19, 2026, 2:50pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/10 "2026-09-19T14:50:05Z")
> [@wolfrose](#): > > But the issue now is that I need to design the drivetrain system to buy the mechnical parts; like, pulleys, belt, bearings and the carden. AI does not seem to know what a "carden" is. Can you help with a description? ---
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 3:02pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/11 "2026-09-19T15:02:38Z")
> [@xfpd](#): > > Do you know, "AI" will churn out infinite answers, without a microsecond of original thought? It finds all the projects according to your input, statistically analyzes them, then cobbles together a guess. > > wolfrose: I know that, I've been discussing this topic with different AIs for weeks. I asked ChatGPT to generate me with blueprints or drawings but it provided me with things that aren't practical. Like these ones: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/c/9/a/c9a21e7b3b439b897e9a8e6fabfa8260fb4a7e38.jpeg) And many other, this one is the final question today, I asked ChatGPT to design me a basic sketch for this model of pulleys + belt system: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/7/6/f/76f6215e9a23cb4550c002f175adea504ab129e4.jpeg) And it's obvious that can't be done in L25cm x W25cm x H10cm robot chassis. > [@xfpd](#): > > Use what you know. Evaluate. Test. Stop asking AI. It will never help unless you tell it what to do. The problem is that I don't want to order that parts ChatGPT recommeded me to get, and then discover that I should have paid more attention and focus before purchasing. ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 19, 2026, 3:07pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/12 "2026-09-19T15:07:24Z")
Let's back up a bit and talk about what you know and have done. Have you EVER built any thing mechanical at home or in school? ---
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 3:07pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/13 "2026-09-19T15:07:25Z")
Like this one: ![image](https://europe1.discourse-cdn.com/arduino/original/4X/2/1/1/211751cb946c3117fa983e99d6c2599aa34fa69a.jpeg) Here I asked ChatGPT to provide me only with the mechanical system from the motor to the main pulley along with the front/rear pulleys. And this is what I got 🙂 I'm trying to follow this guy's design: [https://www.youtube.com/watch?v=63go-gQNn5o&t=2s](https://www.youtube.com/watch?v=63go-gQNn5o&t=2s) Not the exact mechanical system, because I haven't and not planning to buy like those gearboxes. But I want to follow the basic concept which is using only 2 motors. ---
**Author:** ![wolfrose](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wolfrose/32/223333_2.png) [@wolfrose](https://forum.arduino.cc/u/wolfrose)\ **Post date:** [September 19, 2026, 3:09pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/14 "2026-09-19T15:09:47Z")
I've worked on this robot arm for months: ![robot_arm](https://europe1.discourse-cdn.com/arduino/original/4X/7/e/1/7e1870f6e1f0e4ce73339d73a61f662736b5bb60.jpeg) ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 19, 2026, 3:15pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/15 "2026-09-19T15:15:39Z")
> [@wolfrose](#): > > But I want to follow the basic concept which is using only 2 motors. Please describe what you believe is the basic concept! What part of the U-TUBE machine is the basic design? Begin be making a drawing of that basic design. ---
**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\ **Post date:** [September 19, 2026, 5:09pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/16 "2026-09-19T17:09:07Z")
Your images are awesome. Ask chatgpt to build penrose triangle step by step.. 😄 ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 19, 2026, 5:46pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/17 "2026-09-19T17:46:22Z")
> [@wolfrose](#): > > I've worked on this robot arm for months: Then you are very familiar with torque and speed of movement. What are the torque and speed of movement for your vehicle? ---
**Author:** ![xfpd](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/xfpd/32/1120236_2.png) [@xfpd](https://forum.arduino.cc/u/xfpd)\ **Post date:** [September 19, 2026, 7:02pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/18 "2026-09-19T19:02:27Z")
@wolfrose - Stop asking AI for anything. Those AI images are a terrible... especially the Penrose/Mobius belts that flip over and exit pulleys sideways... stop asking AI. It knows nothing and creates nothing but chaos. In your own hand, draw the thing you want to make. The image in your Post #1 looks like a great start. Start with drawing a box. Add some wheels. Describe the purpose of the box (the image has a camera, a distance sensor, maybe some IR detector, et c.). Describe how you expect the wheels to move (four independent motors? two drive wheels and two non-drive, steering wheels, slow like a Mars Rover or rapid like an RC car? Will it be RC or autonomous?) Something like this is on the market... so adding the microcontroller, power supply and code to drive it would be the next step. Then add the peripherals ![image](https://europe1.discourse-cdn.com/arduino/original/4X/c/b/f/cbfc97d6ab47e25798674f8d8ab365ee45c249be.jpeg) By the way, this is a "pillow block" for axle rotation... "AI" did not know its use and has a belt running through it... stop using AI. ![image](https://europe1.discourse-cdn.com/arduino/original/4X/a/5/7/a5774840e173a17ef9210655829bda142b2d0585.jpeg) ---
**Author:** ![Wawa](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wawa/32/1211303_2.png) [@Wawa](https://forum.arduino.cc/u/Wawa)\ **Post date:** [September 19, 2026, 7:07pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/19 "2026-09-19T19:07:14Z")
> [@Paul\_KD7HB](#): > > AI does not seem to know what a "carden" is. Try "cardan". ---
**Author:** ![Paul\_KD7HB](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/paul_kd7hb/32/1127958_2.png) [@Paul\_KD7HB](https://forum.arduino.cc/u/Paul_KD7HB)\ **Post date:** [September 19, 2026, 7:20pm UTC](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219/20 "2026-09-19T19:20:04Z")
Ah! Thank you. A universal joint to couple two shafts meeting at a slight angle. For the OP purpose a rubber u-joint would be best for slight angles. Best if built with no angular difference. A rubber coupling eliminates the speed changes/jerking as the simple u-joint rotates. [Next page](https://forum.arduino.cc/t/how-to-design-3-1-pulley-belt-system-for-a-ugv/1460219.md?page=2)