The motors are actually terminated in wye, I took one apart to check this.
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Thank you very much for the suggestion, I think you are right, so far I was concentrating on finding hub motors much smaller than the inner diameter of my tires. I did some measuring, I could get away with a hub motor with an outer diameter of max 83 mm, this will still be small enough to have a few millimetres to spare for a 3D printed rim which fits my tires. Hover board motors are unfortunately of such a large diameter that they will probably not fit. I used all my paint skills to make a drawing to illustrate:
This is a side view of my current 3D printed rims with the two measurements indicating the max size of a possible hub motor. The red lines are the rubber of the tires.
I could fit a hub motor reaching trough on both sides (green rectangle) which must not be larger than 83 mm in diameter or I could fit a hub motor completely inside of the tire which must be quite narrow (not more than 44 mm) and be less than 150 mm I outer diameter. Marked with the pink rectangle.
I think I will try to find something within those limits, 5" scooter hub motors look quite promising, though it is not so easy to find drawings or measurements on the various vendor pages.
The rover will be not very heavy say 15 - 20 kg as a maximum. Its just for cruising and crawling about a bit and maybe using as a snow plough or pulling sledges in winter. So I completely agree, 6 motors with letâs say 3-5 Nm torque each should work nicely.
Using VESC and hall sensors should give me slowest speed control for crawling, at least this was my impression.
Also why not just replace the wheels entirely with these⌠theyâre 8 inch escooter wheels so they have the same outer tire diameter as the wheels you want to useâŚ
To be honest, the shape was more or less accidental. I started with the diameter of the motor and the 3 holes for the screws. Then I added a lever with lots of hollow open space below to avoid accidental pressing on the scales nearer to the motor than the necessary 103 mm. I wanted a round contact point and some strength against bending. Working with curves I arrived at this shape, which I only realize now looks a bit like a finger or a claw 
The tires I want to use are proper RC crawling rock crusher tires with very good grip. I already have 6 of them and I love the look. Of course it would be much more convenient to use 6 of the shelf hubs with reasonable suitable tire profiles.
Another point is, that 8 inch hub motors are quite heavy. I would prefer having less motor volume in my wheels. I will see what can be found and if I canât find something suitable, I will most likely follow your advise.
You can do a lot more current than 11 amps. If thatâs what u were thinking. Thatâs just a made-up continuous current number. U could likely do maybe 4x-5x that before saturating the stator and even then u could keep adding more current and get more torque.
The blue line ⌠surely thatâs not the torque output and u wonât produce less, just not the same linear increase
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Interesting, I was quite sure that I had had already reached a point where I got even less torque out of an increased current during my test, that is why I stopped at 11 A. Maybe the problem is with my setup measuring stall torque. The lever can only travel a few cm before being stopped by the surface of the scale. Then I am waiting for the VESC data to reach a somewhat stable level before writing down the data point.
I will certainly set up my test rig again and have another go. I know that the specs I got from the seller of the motors are not reliable, however I was a bit worried of burning the motor windings with an increased current. I am wondering whether the stated 12 A nominal current are the motor current or the current from the battery. Anyhow, running the motor @ 44 A to 55 A seems very hot to my mind.
I would recommend two hoverboard motors. ($50 from a broken hoverboard locally). And use a gear/pulley system to drive the other 4 wheels.
They have more torque than needed, and can go fairly fast for a crawler robot.
The hub motors spin too fast and require lowering the ratio to maximize power at slower speeds
Check out this similar robot with 4 hoverboard motors: 4troller - First test - YouTube
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The phase wires coming out of your hub motors look tiny.
Another consideration with vesc is it doesnât have âboosted board style duty cycle controlâ⌠and by that I mean 50% throttle wonât give you 50% maximum speed like it does on a boosted board⌠50% throttle on a vesc will you bring you right up to the motorâs no load speed.
Well, the three phase wires are AWG 20 = 0,518 mm^2 of copper which is not much by a long shot. However the actual windings consist of 7 strands of 0,25 mm wire (outer diameter) with a cross sectional area of 0,05 mm^2 each, a total of 0,35 mm^2. I am quite fearful of driving 12 A or even more through this tiny cross section.
Thank you, thats a nice setup, however, I wold like very much to use my high quality crawling tires. The usual rubber on hover board wheels is of quite a low quality.
I just redid my measurements and sure enough, I found a mistake at 10,5 A. I had a wattage limit of 100 W in my settings and I did not notice, that my max current was limited to about 10,7 A. So starting with 11 A my set motor current never reached my settings. After setting the limit to 200 W, I went up to 12 A motor current for real this time, with mixed result in torque, as my test bench is quite elastic and flexes under load which affect my readings. I will need to build a sturdier test bench and lever.
However, the motor got quite hot even at 12 A and me only applying power for each measurement step for 10 - 20 seconds. After 3 passes with 12 A the outer metal parts of the motor reached about 65 °C and I guess the core temperature was at least 70-80 °C. It smells of hot metal and oil. After all, the windings have a cross section of only 0,35 mm^2. I think I should not go above 12 A in my experiments.
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Getting hot isnât good of course but the magnet wires likely are rated to 180c or 200c meaning they can sustain that high temp for 20,000 hours. Maybe the motor specs say 12 amps and supposedly the motor could continuously sustain that current and not burn up, but for sure you can do bursts of much higher.
Whatâs the goal? How much torque you need and for how long?
Well, I do not have an exact number. I want to be able to do some crawling therefore the motors must be strong enough to lift the front of the rover (maybe 10 kg) up a curb. For this I will need about 4-5 Nm from each front wheel motor.
I think I might give those motors a try:
They fit the available space inside of my tires quite nicely and I should think with their larger diameter they will have more torque than my small skate hub motors.
The 5.5 inch hub motor is marked green in the drawing, the rims are red and purple.
Technical data is available a plenty as usual: 
I already asked the shop for a datasheet, hopefully I will get at least some informationâŚ
Combien de contrĂ´leur utilisez-vous et comment ils sont branchĂŠs pour faire fonctionner 6 moteurs merci