Possible drivetrain for a crazy remote control car.
Chris Cristini, Mon Mar 30 2009, 02:51AMI have a bunch of gears and most of them are planetary sets. I want to build a case some how to hold all of them along with a small 1/2HP electric motor if doubling voltage doubles HP and torque other wise it is 1/4HP at 18V this is the closest motor I could find that is like mine but it is 12V and not 18V
I want to buy this one and I still have to build a motor controller for my 36V battery pack and a charger lol.
Re: Possible drivetrain for a crazy remote control car.
Electroholic, Mon Mar 30 2009, 03:27AM
brushless is the way to go man.
Electroholic, Mon Mar 30 2009, 03:27AM
brushless is the way to go man.
Re: Possible drivetrain for a crazy remote control car.
Zenador, Mon Mar 30 2009, 01:56PM
So the first question is what scale is your planned car? I raced 1/10 scale electric and nitro competitively years ago.
The gears in the pics could be used as a differential, but a driveshaft/transmission would be almost out of the question. All kit-based RC cars and trucks can be tuned for speed or torque by changing the pinion on the motor and sprocket on the drive shaft. For a stock class race, it was 13T/42T. The planetary gears would be next to impossible to tune.
32V battery pack is way too much for an RC car. 7.2V 3000mAh is the norm. At 32V on a brushed motor (as pictured) you will melt the brushes and the commutator. Torque would be so high for a light chassis that you would just spin the tires.
My "hot" electric cars (fewer turns on the motor, small pinion, @7.2V) would top out at 80km/h (50mph), and my nitro cars - with a 2 speed automatic transmission - topped out at 120km/h (75mph).
Brushless is a great option, but the motors are a little more $$, as are the controllers. My father runs brushless in his electric RC planes. For stupid fast brushless motor setups, google "RC pylon racer"... Some of these setups fly at over 200mph, and a few use planetary gear setups on the pilot shaft.
Z
Zenador, Mon Mar 30 2009, 01:56PM
So the first question is what scale is your planned car? I raced 1/10 scale electric and nitro competitively years ago.
The gears in the pics could be used as a differential, but a driveshaft/transmission would be almost out of the question. All kit-based RC cars and trucks can be tuned for speed or torque by changing the pinion on the motor and sprocket on the drive shaft. For a stock class race, it was 13T/42T. The planetary gears would be next to impossible to tune.
32V battery pack is way too much for an RC car. 7.2V 3000mAh is the norm. At 32V on a brushed motor (as pictured) you will melt the brushes and the commutator. Torque would be so high for a light chassis that you would just spin the tires.
My "hot" electric cars (fewer turns on the motor, small pinion, @7.2V) would top out at 80km/h (50mph), and my nitro cars - with a 2 speed automatic transmission - topped out at 120km/h (75mph).
Brushless is a great option, but the motors are a little more $$, as are the controllers. My father runs brushless in his electric RC planes. For stupid fast brushless motor setups, google "RC pylon racer"... Some of these setups fly at over 200mph, and a few use planetary gear setups on the pilot shaft.
Z
Re: Possible drivetrain for a crazy remote control car.
aonomus, Mon Mar 30 2009, 02:16PM
Planetary gear reduction is the best way to make brushless practical for lower speeds, but unfortunately brushless requires a ESC, but it has the advantage of not wearing out brushes and its being used more and more for high performance/long lifetime applications.
If you didn't know already the term 'kv' in reference to brushless motor means RPM per volt, so you can pick a motor to suit your target RPM range with your gear reduction and voltage.
Oh, also, brushed motors can be driven by voltage or using PWM off a fullbridge or halfbridge, but a ESC requires a control signal identical to how servo motors is controlled.
aonomus, Mon Mar 30 2009, 02:16PM
Planetary gear reduction is the best way to make brushless practical for lower speeds, but unfortunately brushless requires a ESC, but it has the advantage of not wearing out brushes and its being used more and more for high performance/long lifetime applications.
If you didn't know already the term 'kv' in reference to brushless motor means RPM per volt, so you can pick a motor to suit your target RPM range with your gear reduction and voltage.
Oh, also, brushed motors can be driven by voltage or using PWM off a fullbridge or halfbridge, but a ESC requires a control signal identical to how servo motors is controlled.
Re: Possible drivetrain for a crazy remote control car.
Chris Cristini, Mon Mar 30 2009, 02:42PM
My plan was to throw something simple and powerful together without spending crazy amounts on parts just a project to keep me busy. And it will teach me a little more about gear ratios and motor controllers if I build all of it just doing it for the experiance and the fun.
My motor rotates somewhere around 22.000RPM my gear set is 10 to 1 ratio so I should get 2200RPM with alot of torque.
Chris Cristini, Mon Mar 30 2009, 02:42PM
My plan was to throw something simple and powerful together without spending crazy amounts on parts just a project to keep me busy. And it will teach me a little more about gear ratios and motor controllers if I build all of it just doing it for the experiance and the fun.
My motor rotates somewhere around 22.000RPM my gear set is 10 to 1 ratio so I should get 2200RPM with alot of torque.Print this page