RCCrawler Forums - Motor T Figure

In EeePee's CR-01 Thread he posted a chart that showed the RPM/Volt
Revs Per Minute per Volt of Various Turn Motors

As Such.

Originally Posted by EeePee http://www.rccrawler.com/forum/image...s/viewpost.gif
Holmes Hobbies has a great little chart I can refer to:

Motor speeds (taken from random and averaged sample @ zero timing & 3100rpm):

10t = 6526 rpm/volt
15t = 4317 rpm/volt
17t = 3753 rpm/volt
20t = 3216 rpm/volt
21t = 3082 rpm/volt
23t = 2790 rpm/volt
25t = 2588 rpm/volt
35t = 1565 rpm/volt
45t = 1210 rpm/volt
55t = 987 rpm/volt
65t = 837 rpm/volt

That's Per VOLT so if you use 7.2 Volt then multiply those Figures by 7.2 to get your Motors Total RPM.

I sat and calculated these figures to Actual land speed via the Gearbox Ratio and how many times the wheels actually turn per minute, and then the wheel circumference to get how far that many turns will take you.
Multiplied by 60 to get a figure in speed/hr

This is also assuming that the Diffs don't then provide a different Ratio again.

Bear with me I am Aussie so I use Metric figures

10t = 6526 rpm/volt x 7.2v = 46980rpm
Multiply that by 60 (Minutes) = 2818800 Revs per Hour
Divide the R.P.H by Standard Gearbox Ratio of 40.5 = 69600 Revs per Hour for the actual Wheels.
Wheel Radius including tyres is approx 6 centimeters (cm)
This gives a Wheel Circumference of 37.7cm approx
So Multiply 37.7cm by 69600RPH = 2623920cm/hr
Divide 2623920cm by 100 (100 cm per Meter) = 26239.2 meters/hr
Divide that by 1000 (1000 Meters per Kilometer Km) = 26.2km/hr approx. or 16.3mph for you Imperial guys.

I will do Each of the Motors listed with Kmh and Mph figures.

All are approx. rounded to nearest percentage figure

10t = 6526 rpm/volt = 26.2Kmh - 16.3Mph
15t = 4317 rpm/volt = 17.3Kmh - 10.7Mph
17t = 3753 rpm/volt = 15.1Kmh - 9.4Mph
20t = 3216 rpm/volt = 12.9Kmh - 8Mph
21t = 3082 rpm/volt = 12.4Kmh - 7.7Mph
23t = 2790 rpm/volt = 11.2Kmh - 6.9Mph
25t = 2588 rpm/volt = 10.4Kmh - 6.5Mph
35t = 1565 rpm/volt = 6.3Kmh - 3.9Mph
45t = 1210 rpm/volt = 4.9Kmh - 3Mph
55t = 987 rpm/volt = 3.9Kmh - 2.4Mph
65t = 837 rpm/volt = 3.4Kmh - 2.1Mph

Now if you want a Trail Rig like I do and wish to walk along with it then you'd best look at a 55T motor maybe a 45T depending on your walking speed as Average walking speed is apparently approx 5kmh - 3.1Mph

I think I need a Lie down now after that