Hi all, just dropping a line here to say hello and thank you all for the help so far. I've spent more than 50 hours in the past 3 weeks reading through the forums here ironing out my idea. I've finally decided to register so I can see higher res pictures and of course post looking for input!
Like the title says a fresh new guy with a radio control problem. I've never built a go kart, and may have ridden in them all of twice.
I'm working on a project kart that won't have a seat or steering wheel at all! I picked up a nice Futaba 4PLS transmitter and have been sorting out some of the problems associated with trying to control go kart level forces with those dinky little RC servos. I've got the plan sorted out, next up is the execution. The first shipment of parts arrived this week, and now I'm working on simple assemblies while I iron out the details of my frame. I promise pictures as I go along, for now all I have are rough sketches and ideas. Please chime in with ideas on anything and everything here, I'm always open to ideas.
The whole thing is started by picking up a Predator 6.5hp that was $98 from Harbor Freight on sale, and MUCH cheaper than a large RC engine. So far I've got 145/70-6 knobby tires for the rear on a 1" live 32" axle mounted to a subframe that will have 2" of travel in the 12" shocks. The hinge point will be the same center of rotation as the jackshaft in the torque converter thereby eliminating chain length problems while not bouncing the engine all around either. I'm using a 12:45 ratio on #40 chain aiming for 40mph top end. I picked up a GM power window motor to handle the steering since I'd just break an RC servo. I'll be tying it to a Pololu JRK12v12 controller, and power the whole setup with a deep cycle RV or marine type battery. I figure heavy duty RC servos should be enough to handle the throttle and a mechanical disc brake. I'll use a voltage regulator to drop it down to 6v for the RC receiver and other servos.
The current running debates are as follows:
Front Suspension:
I'm torn between double A-arm or J/trailing arm (yes for a front suspension). I'm pretty certain the double A is more sturdy/beefy, but is also more complex and likely heavier. The J/trailing arm is simpler, keeps the rotation within the vertical plane without the camber concerns of A-arm. Of course with only 2" of travel on the 12" shocks and 4.10x3.50-4 knobby tires I'm not sure camber is even a concern? Right now I'm favoring simplicity even though I just found a great post for an A-arm steering setup.
Tubing size:
Square tube, considering 14ga 1" or 1.5". Since there's no person riding on the cart, I figure we get to lose 250lbs from the stress. But stress will be added driving rougher via radio control and off road. The added weight of the 1.5 tube should help increase weight and traction, and since I'm dumping my large rear off the kart I can afford the heavier studier frame. Of course smaller is cheaper and easier to figure into design. Leaning towards 1.5" anyway, it's only money, and a little extra math to build something that will end up being indestructible!
So that's my first post, let's hear the laughter and complaints!
Like the title says a fresh new guy with a radio control problem. I've never built a go kart, and may have ridden in them all of twice.
I'm working on a project kart that won't have a seat or steering wheel at all! I picked up a nice Futaba 4PLS transmitter and have been sorting out some of the problems associated with trying to control go kart level forces with those dinky little RC servos. I've got the plan sorted out, next up is the execution. The first shipment of parts arrived this week, and now I'm working on simple assemblies while I iron out the details of my frame. I promise pictures as I go along, for now all I have are rough sketches and ideas. Please chime in with ideas on anything and everything here, I'm always open to ideas.
The whole thing is started by picking up a Predator 6.5hp that was $98 from Harbor Freight on sale, and MUCH cheaper than a large RC engine. So far I've got 145/70-6 knobby tires for the rear on a 1" live 32" axle mounted to a subframe that will have 2" of travel in the 12" shocks. The hinge point will be the same center of rotation as the jackshaft in the torque converter thereby eliminating chain length problems while not bouncing the engine all around either. I'm using a 12:45 ratio on #40 chain aiming for 40mph top end. I picked up a GM power window motor to handle the steering since I'd just break an RC servo. I'll be tying it to a Pololu JRK12v12 controller, and power the whole setup with a deep cycle RV or marine type battery. I figure heavy duty RC servos should be enough to handle the throttle and a mechanical disc brake. I'll use a voltage regulator to drop it down to 6v for the RC receiver and other servos.
The current running debates are as follows:
Front Suspension:
I'm torn between double A-arm or J/trailing arm (yes for a front suspension). I'm pretty certain the double A is more sturdy/beefy, but is also more complex and likely heavier. The J/trailing arm is simpler, keeps the rotation within the vertical plane without the camber concerns of A-arm. Of course with only 2" of travel on the 12" shocks and 4.10x3.50-4 knobby tires I'm not sure camber is even a concern? Right now I'm favoring simplicity even though I just found a great post for an A-arm steering setup.
Tubing size:
Square tube, considering 14ga 1" or 1.5". Since there's no person riding on the cart, I figure we get to lose 250lbs from the stress. But stress will be added driving rougher via radio control and off road. The added weight of the 1.5 tube should help increase weight and traction, and since I'm dumping my large rear off the kart I can afford the heavier studier frame. Of course smaller is cheaper and easier to figure into design. Leaning towards 1.5" anyway, it's only money, and a little extra math to build something that will end up being indestructible!
So that's my first post, let's hear the laughter and complaints!
to the forum......