Hello I am Josh, I am a forum member. I saw your question and took a look. The motors are 75 to 1 and EZ Robot gets great deals buying in bulk and brings the savings to its members. Here is general information...

Size: 280 × 300 × 130 mm (11" × 12" × 5")Weight: 1.9 kg (4.1 lb)Ground clearance: 60 mm (2.5") when lightly loadedRecommended motor voltage: 2 - 7.5 VStall current at 7.2 V: 6.6 A per motorNo-load current at 7.2 V: 420 mA per motorNo-load output shaft speed at 7.2 V:350 RPM for the version with 34:1 gearboxes160 RPM for the version with 75:1 gearboxesStall torque at 7.2 V:5 kg-cm (70 oz-in) per motor for the version with 34:1 gearboxes11 kg-cm (160 oz-in) per motor for the version with 75:1 gearboxes

Welcome to EZ Robot we look forward to seeing your creativity.

Says nothing about how much load it will take.

I need to make a prototype of a line following robit that can carry parts in a warehouse.

This will be a proof of concept vehicle for now.

Based on the oz in rating of the motors you can expect 30 pounds at 70 percent of the no load max speed and around 45 pounds at half max speed with zero incline. For the "heavier" loads you may want to consider the 6wd version with high ratio gearing since the 6wd version has 2 more motors and tires to share a load. Also for smoother movement I recommend a solid rubber tire swap for the thumpers soft off road tires. Don't worry swap kits are available for both thumpers. The solid tires prevent your robot from squatting under a heavy load and is ideal for smooth floors and warehouse situations. You will need a l298n h bridge for each axle. Best torque comes from running the motors on 12v. It makes a large difference over 7.4 volts that many rc car battery packs are.

Thanks for the information.. I will be posting how thsi works out.

Hi,

Just purchased Thumper 4WD Chassis With Gripper. Hooked up using video for 2.5 Amp Motor Controller. Seems to be connected but I guess using the power pack that came with kit is too small to move it at all. I hear the connection to moter and it moves back and forth a little.

What size battery is everyone using?

Also can you separate the power from the controller ?

I would like to use 2 different power sources if possible, one for controller and one for motors.

Thanks for the help.

Running it on 12v will not kill the motors?

I run thumper on 2 (in parallel) 7.5v. 1600 mah battery with no issue and it runs great.

but can you run it on 12v sealed lead acid battery or it will be too much?