Hey guys! Not sure if this forum is the correct place to post this as there are several that seem to have elements of the project I'm working on, from go-karts to mopeds to golf carts to robotics. Pleased to meet you all!
My friends and I just started out own cosplay workshop and we wanted to create something that would be fun and recognizable that we can take with us to different events and things.
We're making a 2/3rds scale Metal Slug tank from the game from the game of the same name. It will be about the size of a golf cart and hold a single person.
Designing it in CAD and various other programs, we've put about three or four months into designing various aspects and how we're going to do the body, the chassis, etc. We've also settled on how it's going to move.
If you don't remember pumping a ludicrous amount of money into one of these games at a laundromat or arcade, here's a pic:
One of the key features of the Metal Slug is the way the tank treads on the vehicle look. They don't lie flat on the ground where the idler wheels on the bottom work but instead draw back up into the body. We want to go for the same look, and figured out how. Instead of two treads, we want to use four to give the illusion of two treads being "pinched" back up into the body.
Here's a rudimentary CAD drawing of the drive system that actually shows what I mean. One drive wheel and a tensioner/idler wheel per track, with the smaller wheel hidden inside the chassis. It should work.
The problem we're running into is to figure out the powerplant itself. We have several different ideas, but can't seem to decide on one.
The larger wheels are 16 inches in diameter and the smaller are 10, for reference.
Idea one: 4 wheelchair motors or electric scooter motors
This would involve using four direct-drive wheelchair motors to the "big" wheels, with two on each side. Each side would be wired together. With the right motor controller apparently I can wire up two motors per channel in series as long as the total amp draw doesn't exceed the specs of the controller.
I'm just not sure if four wheelchair motors would be able to move something the size and weight of a golf cart and have enough torque. It's also going to take a lot of power to turn the tank since there's lateral motion applied to the wheels, or finding four identical motors with the same RPMs/speed/gearboxes etc. We started looking at electric bike motors, but are having the same issues trying to figure out if they'd be powerful enough.
Idea two: Golf cart rear end
The reason we thought of this idea was because where I live, it's extremely easy to get ahold of a wrecked golf cart or one where the batteries have gone dead for around $150. This would have all the electronics already needed, the controller, the switches, etc.
The idea would be to mount the rear end in the back of the tank to the two "big" rear wheels and run a chain drive up to the front two wheels so all would be powered. The vehicle would be "turned" by applying the brake on one side slowing the track down and letting the differential make the turn. You wouldn't be able to neutral turn in this, and to be honest I have no idea how strong the brakes on each hub of a golf cart would be or if they would burn up after using it like this. It's a very inefficient way to steer a tracked vehicle, but it's the only way to do it with a single engine and a single differential.
Idea three: Two golf cart motors
This may be the most expensive out of the three but I've seen a ton of IQ Precedent motors on sale recently for around $200. This would be a hybrid of the two different designs, with the motors in the back and a chain drive linked to the front.
The issues I see would be finding two identical motors that run at identical speeds, and finding gearboxes that would work. Most golf cart motors have splined shafts as well and an adapter output shaft needs to be made from scratch.
Since you all have so much more experience than I do in this community, I guess I would just be looking for advice on what motors to use before we move forward with designing this project.
Thanks!
My friends and I just started out own cosplay workshop and we wanted to create something that would be fun and recognizable that we can take with us to different events and things.
We're making a 2/3rds scale Metal Slug tank from the game from the game of the same name. It will be about the size of a golf cart and hold a single person.
Designing it in CAD and various other programs, we've put about three or four months into designing various aspects and how we're going to do the body, the chassis, etc. We've also settled on how it's going to move.
If you don't remember pumping a ludicrous amount of money into one of these games at a laundromat or arcade, here's a pic:
One of the key features of the Metal Slug is the way the tank treads on the vehicle look. They don't lie flat on the ground where the idler wheels on the bottom work but instead draw back up into the body. We want to go for the same look, and figured out how. Instead of two treads, we want to use four to give the illusion of two treads being "pinched" back up into the body.
Here's a rudimentary CAD drawing of the drive system that actually shows what I mean. One drive wheel and a tensioner/idler wheel per track, with the smaller wheel hidden inside the chassis. It should work.
The problem we're running into is to figure out the powerplant itself. We have several different ideas, but can't seem to decide on one.
The larger wheels are 16 inches in diameter and the smaller are 10, for reference.
Idea one: 4 wheelchair motors or electric scooter motors
This would involve using four direct-drive wheelchair motors to the "big" wheels, with two on each side. Each side would be wired together. With the right motor controller apparently I can wire up two motors per channel in series as long as the total amp draw doesn't exceed the specs of the controller.
I'm just not sure if four wheelchair motors would be able to move something the size and weight of a golf cart and have enough torque. It's also going to take a lot of power to turn the tank since there's lateral motion applied to the wheels, or finding four identical motors with the same RPMs/speed/gearboxes etc. We started looking at electric bike motors, but are having the same issues trying to figure out if they'd be powerful enough.
Idea two: Golf cart rear end
The reason we thought of this idea was because where I live, it's extremely easy to get ahold of a wrecked golf cart or one where the batteries have gone dead for around $150. This would have all the electronics already needed, the controller, the switches, etc.
The idea would be to mount the rear end in the back of the tank to the two "big" rear wheels and run a chain drive up to the front two wheels so all would be powered. The vehicle would be "turned" by applying the brake on one side slowing the track down and letting the differential make the turn. You wouldn't be able to neutral turn in this, and to be honest I have no idea how strong the brakes on each hub of a golf cart would be or if they would burn up after using it like this. It's a very inefficient way to steer a tracked vehicle, but it's the only way to do it with a single engine and a single differential.
Idea three: Two golf cart motors
This may be the most expensive out of the three but I've seen a ton of IQ Precedent motors on sale recently for around $200. This would be a hybrid of the two different designs, with the motors in the back and a chain drive linked to the front.
The issues I see would be finding two identical motors that run at identical speeds, and finding gearboxes that would work. Most golf cart motors have splined shafts as well and an adapter output shaft needs to be made from scratch.
Since you all have so much more experience than I do in this community, I guess I would just be looking for advice on what motors to use before we move forward with designing this project.
Thanks!
