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Pololu Tic T834 USB Multi-Interface Stepper Motor Controller (Connectors Soldered) (POLOLU-3132)

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The Tic T834 USB Multi-Interface Stepper Motor Controller makes basic control of a stepper motor easy, with quick configuration over USB using our free software. The controller supports six control interfaces: USB, TTL serial, I²C, analog voltage (potentiometer), quadrature encoder, and hobby radio control (RC)

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Hi can the Tic T834 control 4xDC motors?

I’m building an all terrain 4wd robot and not sure if i need 1 or 2 of these stepper motors.

Thanks for your time!

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Hi Garth,

From what I read the driver is just for stepper motors (without breaking into the chip it might be a bit hard to use DC motors as you can set the speed, steps, direction etc).

If you are using an Arduino I would recommend something like this for smaller motors (up to around 12V @1.2A) https://core-electronics.com.au/quad-dc-motor-driver-shield-for-arduino.html
or something bigger by Pololu again that can do more current and voltage: https://core-electronics.com.au/dual-mc33926-motor-driver-carrier.html

Liam.

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Hi Liam thanks for your reply and appreciate the links.

I just asked another question on your site regarding DC motors-

Hi again, i need 4xDC motors for a 5kg 4wd all terrain robot. I’m confused with the gear ratios. I need a motor with high torque for climbing steep inclines and rough terrain, but also needs to have a burst of good power/speed if i need it. Looking at all the gear ratios has me a little confused so would appreciate any help again thank you! : )

I’m new to DC motors, and all the different gear ratios has me a little confused.

Done a bit of searching but cant find a straight answer, like this motor will give good torque but also good top end speed, etc. That would help me out a lot instead of paying a heap of money on trial and error. :stuck_out_tongue:

Thanks again for your help!

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i Garth
Any use of a gear box to increase torque or any other reason will reduce the maximum end result speed (RPM). After all that is what gear boxes do as with a car or anything else.

In other words, for a given motor you cannot increase torque with a gear box and retain maximum speed. Having a cake and eating it as well comes to mind.

I think you have to do this in a rational manner:
Establish what maximum speed you want. Establish what torque you need to climb expected inclines. You will then have to sort out motor RPM, Gearbox ratio, motor power (torque) to give you the required results. THEN search for a component list to do this. Remember if you are driving all 4 wheels the energy to move the all up weight of your vehicle is shared by all 4 motors. May be wrong but I think most geared motors (motors with gearbox attached) have the max RPM and torque obtained at the gearbox output shaft published.

Once this is done then worry about driving and controlling speed of the motors. If you attempt to guess what may be required here you will be working backwards and possibly find yourself in no end of strife and finish up with some expensive gear that is not up to the job and has no hope of working.
Cheers Bob

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Hi and thanks so much for that reply.

I think being new to DC motors, the RPM, etc figures don’t really help out.

Now if it was a car then this would be very different.

Anyway thanks for your help appreciate it.

Time to do more searching…

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What is the difference. Speed: RPM * wheel circumference (cm) = speed (cm per min). Torque example 10kG/cm wheel 6cm diameter =10/3 = 3.3kG at wheel rim. So I would think 4 wheels at these specs should be able to shift about 12kG on a level surface. I am not far up on these types of maths and could be quite wrong but I think this approach would not be far out. This is not considering any losses such as rolling resistance etc.
If you wanted to be exact no doubt there is enough material on line to be able to do that but you can see that it is not so different to a car. Easier in fact as the car has to consider the wheel diameter at speed which is different from the stationary diameter.
Cheers Bob

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Hey Garth,

Interesting question, @Robert93820 is exactly right, gearing changes the ratio between RPM and torque so the higher you go in ratio the less RPM you’ll get at the same power and you can use the kg/cm to determine roughly what the force provided from each wheel would be (discounting losses and such).

You’ll want to check the ratings on your board/s to ensure that you don’t accidentally go past the max peak current, but if you don’t need the motors to go too quick, and to ensure that you have enough torque to drive the bot you can go with something in the ballpark of 100:1 at 60W. Also note that you can use lower voltages to get less power out to control your speed, PWM for most microcontrollers will also work for this application.

Personally, this is the kind of motor I’d go for if I was putting this project together. Last time I was putting together a project with a DC motor I was driving a prop underwater so high torque low RPM under load was more suitable, but depending on the speed you want to drive your robot at, and how much space you’ve got to mount the motors this would be the sort of gearmotor I imagine you’d be after.

Also, the Tic T834 is actually a stepper motor controller and only rated for 1.5A per phase, for driving a DC Gearmotor like this, you’d probably be better off with a H-Bridge or similar board to control each motor or pair of motors which essentially just acts like an electronically controlled switch to avoid frying your microcontroller, but they do tend to get quite hot (the board I’ve linked below is rated for up to 25A continous which would be massive overkill in this situation, but there should be some other options available which you could use for controlling the motors such as the other boards Liam linked earlier)

All the best with the project! Make sure to let us know if you’ve got any questions :grin:

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Ah i never looked at it like that, so if a DC motor has a torque figure of say 12kg, does that mean i can add up the ratings for each wheel and say it would have a torque figure of 48kg?

I never thought to add them up. :stuck_out_tongue:

So those motors pulling a 6kg chassis would be no problem at all, those motors wouldn’t even feel that weight i think.

Ok i know what to do now thanks again for your help!

Kind regards,
Garth

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Just read the rest of the email that i missed, thanks so much!! :smiley:

I mean i really appreciate this, DC motors are VERY new to me, I’ve only used servos before, so an awesome learning curve and something i can’t wait to get stuck into.

Oh i just ordered a Sabertooth Dual 2x12 Dual Motor Driver for it, i can power 4xDC motors with it.

Thanks very much, the project is going great, now i know which motors to install it’s getting a little exciting. :stuck_out_tongue:

Added a couple of pics of my project, it’s mocked up for the photos.
It will soon be a 4wd all terrain robot.
Will eventually be autonomous with gps and stuff.

IMG20210530162002.jpg

Regards,
Garth

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Hi Garth.
Yes that is right. BUT this figure is related to a point 1cm from the shaft centre so if you have a wheel diameter of say 6cm that figure has to be divided by 3. That is the load is 3cm out from the shaft centre.

I have had a little (I mean little) think about my previous statement about moving 12kG horizontally. It may mean that mass can be supported vertically. You will have to do some research to find out exactly what is meant by this figure and how it is measured.

Take note of Bryce’s reply above. I think that is definitely the TYPE of motor to go for. Which particular one you choose will depend on your research and requirements.

As for the driver, don’t be put off from going too big. Too big will at least work where too small will only be a disappointment and an undue expence.
Cheers Bob

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Well, that should just about drive anything you can fit on the frame.
Those wheels look pretty big and great. Don’t forget the wheel radius has to be considered to establish how much power is available at the outer radius of the wheel.
Cheers Bob

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Thanks very much Bob, Bryce’s reply was fantastic so i will be buying a set of the 100:1 Metal Gear Motors.

Was great to see that so i think those motors will work a treat.

Regards,
Garth

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Yes the wheels are really big but their exactly what i need for the terrain it will be eventually travelling on.

Yep will do, I’ll let you know how it goes once it’s up and running but I’m sure with the size and weight of it and the motors I’ll be getting should move it along nicely…if not I’ll just get something with a little more power or simply change the wheels.

Thanks again Bob much appreciated.

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They would ‘feel’ it, at least initially while the car is accelerating because of Newton 1. Essentially stall torque is exactly how many Nm (I much prefer using Nm instead as kgcm or oz-in is a unit of weight per unit distance i.e. force per unit distance the conversion rate is 1kgcm:0.0980665Nm or 1oz-in:0.0070615518333333Nm)

The motor I linked earlier stalls at 220 oz-in which is approx 1.55Nm, dividing this by the radius of 3cm (0.03m) we get 51.66…N, assuming no losses and all wheels contact the ground, the total force with which the wheel pushes the ground back is ~207N (due to Newton 3 this is also the reaction force driving the car forward) so assuming no losses, given Newton 2 (F = ma) your car should be accelerating at about 29.6ms^-2 i.e. 107kmh^-1s^-1 or about 3g

Clearly, this is a little unrealistic as there’s going to be losses on losses, and this assumes that all motors provide full power constantly, although it should be way more than enough to move the vehicle around, below I’ve attached a little scratch math I used to work this out. Hope it helps :sweat_smile:

And the potential for burning out or dramatically catching fire depending on just how much it’s overloaded and that’s not always disappointing :joy:

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Thanks so much, that information is fantastic and again thank you for going to the trouble to help select the right motors for my build.

Buying the motors today so will be a fun weekend…and also i think they are locking us down for another week, so plenty of time to learn and build.

Thanks again, will place the order today for i have the day off and today was pay day. :stuck_out_tongue:

Kindest regards,
Garth

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Does any one know of a 2 speed gearbox that would be suitable?
My RC car has an auto 2 speed gearbox, that clicks into second speed when it’s rotational speed reaches an adjustable value.

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Hi,
This being a skidsteer autonomous robot with what appears to be a relatively large wheel base - I would recommend increasing your torque requirements by a factor of at least 1.5 -2.0 to avoid disappointment.

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Hey Roland,

Welcome to the forum! Excellent point, here’s where experience will help out a ton!

Liam.

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