Creating a powerful Tracked Robot from 2x $50 Starter motors

[gbaddeley]

I asked OP about forward & reverse, as to make both the tracks go forward, together, the way the motors are currently mounted, the shafts will need to turn in opposite directions.

[TERRA Operative]

What about traction motors from a hybrid vehicle? Although you'll still need the motor controller...

Even statrer motors from a car that does the auto start/stop thing are made for higher duty cycle, but they still have the other problems inherant with starter motors...

My vote is on two winch motors or similar controlled from a pair of cheap Chinese DC motor drives.
You can control them in many ways, including literal potentiometers on foot pedals or joysticks.

Better to click the 'modules' together and have a nicely speed controllable system than 'save money' burning through your money trying things that aren't particularly fit for purpose?

[puppyprogrammer]

I asked OP about forward & reverse, as to make both the tracks go forward, together, the way the motors are currently mounted, the shafts will need to turn in opposite directions.

I'm switching to winch motors as you all have advised I'll let you know how they work once the first test winch arrives.

Btw I just want to state for the record that it would have been pretty interesting to use liquid nitrogen to keep the starter motor cool but that's an experiment for another day 

[Haenk]

Honestly, that winch motor is probably shit, it certainly is not made to last over a longer period of time (minutes). Torque comes from the gearing, of course.
Maybe your best bet is an old (really old) EV from the recycler, something that ran on lead acid batteries.
Other good motors would be industrial, likely 3 phase 400V. Which is not great for creating a fun project. There is a physical reasons, why those 12V are weak...

Enjoy:

[Psi]

Starters are the very worst choice for this kind of application.
They're series wound, and (unless you install some kind of tacho feedback) impossible to speed control.
Also, the're wound for one direction only and if you reverse one of the coils to solve that, they'll have extremely poor torque.

They have amazing torque, its just at 0 rpm. Once they're up to speed it's terrible.
But you can always rip open the starters and run some extra wires out to a few contactors to switch between series and shunt modes on the fly.

That's how the old trolley buses worked, they had a huge leaver you moved to switch between series and shunt.
Series for accelerating from stationary and shunt once you got moving

[Gyro]

They have amazing torque, its just at 0 rpm. Once they're up to speed it's terrible.
But you can always rip open the starters and run some extra wires out to a few contactors to switch between series and shunt modes on the fly.

That's how the old trolley buses worked, they had a huge leaver you moved to switch between series and shunt.
Series for accelerating from stationary and shunt once you got moving

They were actually compound wound, not fully series. This gave excellent controlability of the field flux and so, independently the speed and torque.

If you run some extra wires into the motor in an attempt run it in shunt mode, you will end up with a fire. The field winding (being designed to run in series with the armature) has an incredibly low resistance and will form an effective direct short across the battery. Unlike the armature, [a shunt] field winding doesn't benefit from any back EMF.

[Psi]

Good to know!

[NiHaoMike]

I have seen a starter motor being used for a Frisbee launcher. It spins up a small bicycle wheel, which sat in a cut piece of plywood to guide the Frisbee around as it was being accelerated. Controlling the power was quite crude by adjusting how long the solenoid was activated.

A big problem I see with using it for a robot is that the motor is likely designed to only work well in one direction and will work really poorly if you tried to reverse it.

[Stray Electron]

The white residue surrounding the welded joints looks like you are welding galvanised steel. Be aware of safety concerns. https://en.wikipedia.org/wiki/Metal_fume_fever

  When I took a welding class many moons ago, the instructor warned us about the effects of breathing the fumes from welding galvanized metal and told us that the old time welders drank butter milk to counter act the effects.  I don't know if there's any truth to that but it couldn't hurt.  Personally I can't stand drinking butter milk so I don't weld galvanized metal. 

[puppyprogrammer]

The Winch I ordered arrived, but I'm not sure how I'll attach the sprocket since the winch body is aluminum. 





The sprocket arrives tomorrow. Attaching it will be challenging. I hope I can make it work.

[puppyprogrammer]

Okay, so I still have not figured out a simple way to mount a sprocket onto this winch, so I've set the winch aside for later use and resumed on my plan to use the starter motors.

I created an auto-booting app on the Rasberri Pi v4 which activates the 5v relay shield for 3 seconds every 30 seconds. The relay shield should activate the solenoid, which sends 12v to the solenoid on the start to activate that... but that starter solenoid isn't making any noise.



I suspect I have the starter motor connected wrong. Perhaps the ground isn't working. I'll have to break out the multimeter when the sun goes down a little. I am at 7000 feet elevation so it's like a laser up here. You can see how bright it is in the photos even



On a completely seperate topic though, I've edited my https://commslink.net/chat project so that the AI now has the ability to surf the web on the user's behalf. Kind of cool. You guys should check that out if you like AI chat bots you can talk to with your voice.

I do think I will be able to integrate AI into this robot and talk to it. That will be really cool.

[puppyprogrammer]

I ended up just fully simulated the entire system in 3d to ensure I got it wired correctly. Now I can wire this a little more confidently. My next step is to add a multimeter to the 3d sim so I know what voltages should be where. I think this simulator will revolutionize how I design future robots. The AI assistant is also educated to assist or even make new novel designs I request.

[booscrawl]

AI psychosis? How is 3D relevant?

[abeyer]

AI psychosis? How is 3D relevant?

It's a UNIX system! I know this!

[puppyprogrammer]

3d modeling and testing is relevant. Stop being a boomer

[MariuszD]

Boomers come up with electrical schematics to simplify the drawing as much as possible and focus on what matters.

A 3D render gives the impression that something has been done, but in reality, very little has been done:


Your project should include some kind of speed controller. 100 years ago, a series of resistors switched by contactors were used. Nowadays, electronic controllers are used.

The AI assistant is also educated to assist or even make new novel designs I request.

Use AI for what it's good for - to assist in learning. Don't ask for a ready-made project, ask about the properties of motors, methods of speed regulation, and direction change. Ask about how to measure the motor's characteristics, how to select the gearbox. Ask about what you can verify in other sources. Ask how to find information that might be useful to you but of which you are not yet aware. Ask what difficulties you might encounter when designing the propulsion system of such a vehicle.

Don't be a mindless robot executing the commands of a stochastic machine.
We will verify the quality of your thinking when AI provides you with incorrect data.