Precision Robot Wheels

[geekguy]

Hi,

I have purchased two robot kits from Adafruit. The issue I have is the wheels. They just are not very good at all. They do not roll straight, and wobble quite a lot. Please look into getting some better wheels for robots - precision wheels that roll true.

8-Dale

[Franklin97355]

There are many places to get different types of wheels.
https://www.robotshop.com/en/robot-wheel.html
https://www.servocity.com/motion-compon ... ion/wheels
https://www.pololu.com/category/24/whee ... ll-casters

[geekguy]

Hi,

While there are many sources of wheels through other companies, and I have ordered stuff from each of them in the past, I would not order from them just to get a set of wheels for a robot. Wheels are add on items that should be carried by the same company that sells the motors and servos so that compatibility can be assured. I prefer to order when I can make an order large enough to get things such as free shipping or free items. Adafruit really should get a few sets of better wheels.

8-Dale

[adafruit_support_bill]

Which kit and wheels in particular are you having a problem with?

[geekguy]

Hi,

These wheels in the little red robot kit.

8-Dale

[adafruit_support_bill]

In this case, the issue is as much with the tolerances of the motors as it is with the wheels. These motors have plastic geartrains with simple plastic sleeve bearings that have substantial play. Even a precision machined wheel would exhibit some wobble when attached to these motors.

We currently do not carry as extensive a selection of precision gearmotors and wheels as you can find at the links posted above. But we thank you for the feedback and I will forward your suggestion to our products group.

[adafruit2]

yah while we are getting more robotics parts in the shop, those motors are plastic gear motors. the wheels themselves are actually really good, better than many of the other samples we've gotten for the TT plastic gear motors.

for precision motor'in check out the metal gear motors at pololu. they're 3 or 4x more expensive, but they're definitely higher quality. we don't stock metal gear motors at this time.

these servos are also good quality (but, likewise, about 4x more expensive)
https://www.adafruit.com/product/154

[geekguy]

Hi,

Would any wheel that calls itself a servo wheel work for these little motors? While I would love to switch out the motors for micro metal gear motors, I would have to have some sort of bracket that would mount them to a chassis. I do not own a 3D Printer, which would make this an easy problem to solve.

8-Dale

[adafruit_support_bill]

Servos come with different spline patterns. Those particular motors have a 21 tooth spline.

[adafruit2]

the servo wheels we stock tell you what servo they go with, its not a universal mounting system

[geekguy]

the servo wheels we stock tell you what servo they go with, its not a universal mounting system

I see that now.

I am just a little bummed because I have broken one of my DC Motor Controller FeatherWings and need to replace it. I am considering whether to go with a different robot platform, although I really want to see how much stuff I can get onto this one. I figured out how to add two VL53L0X with a TCA9548A I2C Mux, Bluetooth, and an IMU to it.

8-Dale

[adafruit_support_bill]

That is definitely a great chassis for experimentation. It has lots of flexibility for sensor mounting and expansion. One nice part about a differential drive (a.k.a."Tank Steering) chassis is that it is relatively easy to port your sensors and navigation code to another differential drive system when you outgrow that one.

Personally, I prefer the mini-round chassis to the rectangular one. The stock motors are a little more robust, and the flat chassis plates have more mounting holes, so it is a little more easily adapted to higher-end drive motors like the Pololu Micro-metal gearmotors.

The Boe Bot is another nice expandable platform. The chassis and drive system is pretty much designed around the Parallax CR servos. But as CR servos go, they are pretty rugged and smooth running.

[geekguy]

Hi,

I have this one, which is what my Little Red Rover is based on, and this round one, which I have not assembled yet. If the red one was just big enough to use at least micro metal gear motors (encoders or no encoders) with good wheels, it would be super awesome, and it is a good size. I just want a fairly inexpensive platform I can base my robotics experimentation on. I have ideas for a small robot that uses a Raspberry Pi 3 with a Circuit Python board like a Feather M4. I have already had a Raspberry Pi using ROS to communicate with an Arduino, so I do not think it would be difficult to have it talk to a Circuit Python board.

If there were a solid platform that came in at around $50.00 including motors and wheels, I would jump on it. It should have a nice metal chassis. I would like a two wheel platform that is easily expandable to four wheels like my Little Red Rover. I think Adafruit is in a perfect position to design and bring such a small robot platform to market. You will need to design a custom chassis that is expandable to multiple decks though. I do not think there is currently anything out there that fills these specifications, and I have been looking everywhere.

I love you guys and what you do with and for education! You build breakout boards that use components I would never have access to otherwise. I am anxiously awaiting a small order that has my SPI Bluetooth module, so I can start working with it in Circuit Python. I want to see Circuit Python advance and grow!

8-Dale

[adafruit_support_bill]

I don't know what tools you have at your disposal, but it should be possible to adapt micro-metal gearmotors to your red rover chassis with a bit of work. Pololu does sell mounting brackets for these motors. You would need to drill some holes in the platform - and possibly add a shim to ensure that the shaft sits low enough to clear the servo cutout.

[geekguy]

I don't know what tools you have at your disposal, but it should be possible to adapt micro-metal gearmotors to your red rover chassis with a bit of work. Pololu does sell mounting brackets for these motors.

Unfortunately, I do not have the tools I would need to do the necessary customization of the chassis. I wish I did!