AFX Mega G+ Testing
Recently I received a couple of the new AFX Mega G+ cars, a generic Gen 6 Chevy SS NASCAR and a generic modern open wheel F1 type. The Chevy body is very well done, I wonder if people would be willing to pay extra for an actual livery. The tampo printing on both cars was very sharp and clean. The F1 body is the same as the previous Mega G types except that the front wings are not as wide. The complete Chevy weighed in at 17.7 grams, the body is 5.4 grams and the chassis is 12.3 grams. The complete F1 is 15.5 grams, the body is 3.3 grams and the chassis is 12.2 grams. The slight difference in chassis weights is probably due to rounding off. A complete example of the original Mega G F1 car weighs 16.2 grams.
The front axle has a great deal of side play, spacers would have to be added to make these legal for most organized racing. I also noticed that the rear wheels on both cars appear to have a bit of runout.
The width of the chassis is 0.700 inches in the middle, the wheelbase is 1.7 inches. The front tires are 0.390 inches in diameter, the rear tires are 0.462 inches in diameter and the rear wheels are 0.275 inches in diameter and 0.250 inches wide. There is enough space for wider rear wheels and tires.
The traction magnets are neodymium and are not quite flush with the bottom of the chassis. The chassis has a bit more ground clearance at the front than at the back. I did not attempt to remove the can style motor. There is a wire that goes from the circuit board for the RFI suppression components to the top of the motor. The solder connection for the wire is the highest point on the chassis. I did find that one of the pickup shoes on the F1 car would hang up if it was pushed all the way up. I filed the shoe a little to prevent that. The guide pin touched the bottom of the slot on some old Aurora lock and joiner track, my MaxTrax also has a rather shallow slot.
I checked the strength of the traction magnets, they read 2600 gauss, about the same as the ones in my original Mega G car. I also checked the motor and measured 60 gauss on the bottom. The motor would probably be too far away from on the track rails to add much downforce.
Before I put the cars on the track I oiled the motor bearings and rear axles, shortened the guide pins and adjusted the pickup shoes to ride flat on the rails. The track was set at 18.5 volts.
First I took the original Mega G F1 car for a spin, it has Wizzard slip on silicone tires and it turned my track at 3.320 seconds. The Mega G+ F1 car was a bit loose and it did a 3.861 second best lap. With the silicone tires the car did 3.556 seconds, it was still sliding just a little. The Chevy SS wanted to de-slot before it would slide, limiting the pickup shoe travel fixed that and the best time on the stock tires was 4.100 seconds, switching to the silicone tires only lowered the lap time a little to 4.097 seconds. With the F1 car I could hear a little drumming sound from the wheel run-out.
I decided to try using some aftermarket wheels, when I pulled off a wheel I discovered that the end of the axle was knurled and that the axle might not have been straight. The rear axle assembly from the Mega G did not appear to fit. I may dig up a 0.059 inch diameter axle and do a new rear axle assembly with the original gear and boss plus the aftermarket wheels.
I used an old Cidex Omni diode controller and that worked perfectly with the new cars. I used just a touch of brakes. A 90 ohm Parma controller with the brake wire disconnected also worked very well. I also tried a 60 ohm Parma and that would do in a pinch, a 45 ohm Parma was just a bit too sensitive. If you run your track at a higher voltage than I do you would certainly want to use a higher ohm resistor.
It looks like these cars will be good runners right out of the box, they are not quite as fast as the earlier version, but should be very close with a tire change. It is too early to tell how the cars will hold up, but at least the pickup shoes seem to hold up well. I don't think it will be practical to rebuild the motors, but can type motors tend to last quite a while.