Asked — Edited
Resolved Resolved by CardboardHacker!

Ideas For My New Ez-Robot Developer'S Kit

I got a Developers kit for my birthday, and I'm still debate what I'm going to do with. I originally wanted a humanoid-style robot, but the servos most likely won't stand up to the weight. My final design is in the picture below. I went for the rover style robot with an added arm/claw. I however am still open to ideas. Here is what i would like to have ideas for:

Materials: I need something low cost and easy to work with.

Size: How big could the base be? I know I already have the dimensions, but the only DIY building experience I had was with LEGO Mindstorms. I would like the claw to be able to reach over the edge of the robot.

What could I use for a caster?

And just anything that might help.

Thanks and happy building,


User-inserted image


Upgrade to ARC Pro

Your robot can be more than a simple automated machine with the power of ARC Pro!


Wood, would make a cheap base... However, for an arm that size you going to need some serious servos in the base (shoulder) like a Hitec HS-805BB giant Scale servo and for the elbow something like a Hitec 755HB giant Scale Servo... I would also recommend some DC motors instead of the CR servos that came with your kit... This means you will need a motor controller too.... To keep things within the contents of your kit you are going to have to shrink down your design and lighten it quite a bit... Also you can buy cheap furniture castors of various sizes from pretty much any hardware store...


Servo city gearboxes allow you to easily get 3 to 5 times the torque from a standard servo. They are worth it for shoulder s and elbows for a robot.


You can also use ebay and to search for robot kits. Some even come with two motors and wheels as well as a small metal ball bearing castor.


I can give a few insights on your design.

  1. Depending on the arms weight and weight-lifting abilities, you're going to need some weight in the back of the bot to keep it from tipping.

2.If your using the basic robot drive style, the closer the drive motors are to the center the better, so depending on the scale of your bot, it might not be able to turn properly.

3.The pan/tilt servos would need to be supported to avoid I.Breaking the servo drives, and II.Keeping the mount from breaking under stress.

  1. The large boom for the ping I don't think is really needed.

User-inserted image

Size of 2ft long by 1-1.5ft tall would be ok in my opinion.

In my drawing, the sides could be painted cardboard, with a skeleton of light wood, and a wooden sheet as the bottom of the bot. Cardboard for the turret and light wood for the arm.

Enjoy your new adventure! Tech


First of all, thanks for all the help! I would proably break my kit if I had not asked. Second, any videos/ web pages that could help me with stuff outside of the kit, like the DC motors? Like I said I am only 13 and don't have many resources/ people that I could go to. where could I get a gearbox? I think I will try to use some of those.

@technopro: thanks for the diagram and the weight distribution thing. I didn't think of that.


I'm 14. You'll learn. Motors and battery go hand in hand, so you have to know the motors, and then get an ok battery.

Motors, you have to know how heavy the bot will be. My guess is under 10lb. These are motors I used. Not strength tested but touched them to a battery and the shook the bot with the torque.

To use the motors, you need to get the L298n hbridge(2.5A motor controller) from the ez-robot shop or somewhere else. Here you go, but ad looks a little sketchy for the price.

United Kingdom


any videos/ web pages that could help me with stuff outside of the kit

There is plenty of info in the forums for things outside of the kit.

I've written a very detailed tutorial on the L298n H-Bridge which is used to drive DC motors. There are also tutorials from EZ-Robots on this if you click the ? on the H-Bridge control in ARC. Plus there are example projects in ARC for using a H-Bridge.

I've also written a few other tutorials, as have EZ-Robots and a few others in the community. Just have a browse through the site and forums.

If there's something you can't find just ask, the community here is awesome and will help you every step of the way. Don't be afraid to ask no matter how stupid you may think the question is.

Depending on the size of the robot and where the drive wheels are etc. you may not need any counterweights, adding them may give additional weight that would reduce the lifetime of the batteries or require stronger motors. While it is always a good idea to check out a design properly and a lot of the time counterweights may be needed it isn't always the case.


Thanks to everyone for helping! I will be using the information I got to build my new robot. Name coming soon!

It will be awhile before I can actually build the robot, we are moving to Florida in three weeks and I probably won't get my kit until then. We won't get into our house until two or three weeks afterwords, then we have to move all the boxes, ect, so it i probably won't be on the forum for a while.


Sad times dude , we enjoy napkin sketches. Keeping it small as you can is a good general room and that keeps the cost as low as possible. So anyways the gearboxes were . They have some nice equipment for the hobby area of robotics. Also stepper motors and pulleys can be used in your arm if you don't want to use the rc servo gearbox


Sad news? He's moving to Florida:).... That's awesome news... I am totally jealous... If it wasn't for giving up my health care here in Canada, I would buy up some of your cheap property in Arizona and enjoy 300+ days of sunshine a year... :)

Let us know when you get your kit...


I will! I am going to post it here and on YouTube. Thanks for the support on my robot!