Slot Car Motors - Useful Information
Slot Car Motors - Useful Information
Lately, I've received some emails asking about the different motors that are available on the website. The questions are about torque, braking, size, compatibility, etc. Here's a (not so) quick rundown of the important things to know about slot car motors we use on a regular basis for home and club 1/32 scale racing.
SIZE AND FORMAT
First of all, there are three main formats we use (of course, there are more but I'm going to keep this simple for now): FC130 (short can), FK180 (long can) and FF050 (slim can). Of course, if you want to replace a motor in a car, you have to use a motor of the same size, unless you change the motor mount (when possible). For Slot.it and compatible cars, there are many motor mounts you can choose from.
FC130 motors are the most popular ones and they come standard in most Scalextric and Carrera cars (picture above shows a MR Slotcar FC130 motor). Because of their relatively small size, they can be used in a sidewinder configuration, in addition to the more typical inline configuration.
FC130 Motors: Piranha, M/T Racing M/T-1, MR Slotcar FC130, Slot.it V12/3
FK180 motors are becoming more and more popular in out-of-the-box cars, mostly for modern GT or LMP cars, also for all Sideways Group 5 cars. They are longer so they can't be used as a sidewinder motor but are mostly used in anglewinder configurations (can also be used as inline motors).
Variations of the FK180 motor are the Flat Long Can motors from Slot.it. They share the same format except they're not as thick so the center of gravity is lower and they offer more flexibility for the design of the car body (see picture above).
FK180 Motors: M/T Racing M/T-5, MR Slotcar FK180, Slot.it Boxer, Slot.it Flat6
FF050 motors looks like long can motors that have been shrunk to fit in smaller cars. They are mostly found in F1 cars and other very small and/or narrow cars that couldn't fit a bigger-sized motor. Most of them will have a 1.5mm motor shaft instead of the more standard 2.0mm motor shaft found on other motors (there are pinions for 1.5mm motor shafts and also 2.0mm sleeves). The typical orientation for this motor is the inline configuration.
FF050 Motor: M/T Racing M/T-SL1
ENDBELL OR CAN
You will sometimes see those terms used when shopping for a motor, usually when a pinion is included with the motor. The endbell end is the side of the motor where you see the plastic piece (black, orange, yellow, red, etc.) and where the connectors for the lead wire are located.
The can end of the motor is the other (metallic) end. Depending on the car or the motor mount used, the pinion has to be on either side. When choosing a motor mount for a sidewinder configuration, this is an important thing to remember.
OPEN CAN OR CLOSED CAN
Most slot car motors come with some holes in them, on both sides or only on one side. Since there are magnets in a slot car motor to make them run, an open can motor with the holes on the bottom will generate more downforce for those who run on plastic tracks (or Magnabraid wood tracks). Of course, with an open can motor, dust and other «things» can end up inside the motor and create some problems. A closed can motor will generate far less magnetic downforce. On a wood track, it makes virtually no difference and you're far less likely to have problems because a foreign object or dust messed with the internal motor parts.
This is why most Boxer and Flat6 motors from Slot.it are available in both versions, so you can choose the best option for you. And this is also why anglewinder FK180 open can motors have been so popular in the last few years, mostly in Europe where plastic track club racing is the norm. With bigger magnets inside and a longer motor, the magnetic downforce generated by the motor can really help the car to stay on the track, even if magnets are not allowed in the car itself.
SPEED AND TORQUE
The two main technical specifications for any slot car motor is the speed and the torque.
Speed is expressed in revolutions per minute (rpm) at a given voltage. 12 volts is the most used voltage for motor speed so it's easier to compare motors when looking at their speed rating. The stock motor in Scalextric and Carrera cars is often rated at around 18 or 19krpm. Slot.it usually puts 21.5krpm FC130 motors and 20krpm FK180 motors in their cars. NSR cars usually have faster motors in their cars so they're sometimes difficult to control on smaller tracks. RPM's usually are a good indication of the top speed of the motor. Despite this, motors with the same speed rating can deliver this speed in many different ways so you'll have to experiment to find a motor that suits your driving style and the tracks you visit.
Torque is usually expressed in g*cm and is very similar in concept to the torque we get on our real life cars. A motor with more torque will usually have faster acceleration out of the corners and also a lot of braking when you let the trigger go. Depending on the track and your driving style, it can be a good thing but can also be a bad thing. A standard Mabuchi motor in a Scalextric car will have around 110g*cm, our own Piranha motor has around 170g*cm, most Flat6 motors from Slot.it have a little more than 200g*cm of torque and their Boxer motors have more than 300g*cm ! As you can see, bigger motors usually have more torque for the same speed rating.
Now, you're probably thinking that you always want to use fast and punchy motors that have a lot of torque. Not so fast ! (pun intended) Always remember that we're talking about auto racing here so everything is a compromise.
If you run on smaller tracks, top speed is not as big a concern so you should choose a lower speed rating with more torque. It looks like a wise choice but with more torque, you will have less control in the first part of the power curve, control which could be very useful on a smaller track. Also remember that a motor with more torque usually has more braking also so if your driving style is more flowing and less «stop-and-go», you should reconsider your options.
On longer tracks, top speed is important and depending on the type of turns the tracks has (fast sweeping corners or tighter turns), you might want to choose a motor with less or more torque. Always try to find the good compromise between the track type, your driving style, the cars you're driving... and what the rules say!
When choosing a motor, you also have to make sure it will fit in the car it's destined to. When using a non-podded car (no independent motor mount), you'll have no choice at all. Just pick a motor that has the same format, easy.
In a podded car, you'll have some decisions to make and here's some information to help you with this choice. First of all, look at the choices you have for motor mounts in your car. Slot.it offers inline and sidewinder pods for FC130 motors, inline and anglewinder pods for FK180 motors. MR Slotcar makes it easier with only one choice of motor for each configuration. FK180 for anglewinder, FC130 for inline and FF050 for sidewinder. Avant Slot uses FK180 motors only and does not offer a sidewinder option for its cars. An interesting option is the aluminium motor pod from Avant Slot, offering rigidity for maximum performance.
You also have to check if the body of the car will be compatible with the configuration you want to use. For example, the latest LMP cars from Slot.it can only use Flat6 motors in an anglewinder configuration because the rear of the body is so low no other configuration will fit. But other cars, like the Porsche 956/962 can be configured any way you like because there is enough room under the body for any motor configuration you might want. This is also something to consider when making your choice.
Now, if you want to know which advantages each motor configuration has, please see our Newsletter Archive on the subject called «The Anglewinder Hop». You will get good information on the different motor configurations there.
Now that you've chosen a motor and a motor configuration for your car, remember you can still adjust its characteristics by changing the gear ratio. By modifying the number of teeth on the pinion and/or the crown/spur gear, you will be able to get more or less top speed and more or less acceleration and braking. The «standard» gear ratio (if such a thing exists) is around 3.00, which means the crown/spur gear has 3 times more teeth than the pinion so the wheel will make a full rotation every time the motor shaft makes three full rotations.
Changing this ratio is a very important way to change the way your car behaves on the track. Experimenting is the only way to know what you prefer and what's better for your driving style and the tracks you run on. This is just one of the many challenges of tuning a car for a proxy race.
For a complete Gear Ratio chart for Slot.it gears (and any other brand), go to our Reference section on the website.
Now, I think you know everything you need to know to better choose your slot car motor and to find the best combination of speed and control you need to win the next race. Good luck!