I have been struggling with this for a while…
I have an old ~7Kg robot that’s max speed is ~27mph. I want to make a new robot ~10Kg that goes around 30mph and I know I need around 1000 RPM to achieve this.
I tried in vain for a while to effectively choose a motor that will give me the most torque at a certain RPM but I only know how to do this via Torque/Speed curves. Since BLDCs do not provide Stall Torque values ever, how can I do this?
The ODrive Motor Guide creates a set of benchmarks of an example load torque, but I do not know what torque my robot will require. I just want to know what motor will give the most torque safely at 1000 RPM to the wheels.
(Question 1) I know I need the max speed around 1000 RPM, acceleration can be slow like 5 seconds maybe? ideally transmission ratio less than 3:1 using different teeth sprockets only. How do I know which motor is the most powerful for around $100?
(guess 1) Easy way out? Pick a low Kv like 130, and choose the one with the highest rated power.
(guess 2) Or I can chose based on MaxCurrent * Torque Constant for highest Torque.
Motors I am looking at, with some math I may have messed up.
(Question 2) Let’s say I go with Turnigy D5035-125KV (Side Note: What does the D stand for and why is 5035 incorrect with its dimensions?). How do I know how to properly gear this motor? My only guess is to choose a No-Load speed after gearing that is 20% higher than my desired speed.
(Question 3) I’d like to know how much more power I am getting than my old setup
Last Note: My robot is weird… I use Whegs not wheels which will probably strain the encoder and BLDC. So the torque graphs will be very bumpy. That is why I want a high torque motor. I’ll be getting AMT103 for encoding. Any tips here?
To anyone who actually read my full post, Thanks so much! and any help will be greatly appreciated.
A very desperate student.