Help with my robot

If you don’t want to read everything then the most important question i need to ask is
** What parts would i need to buy to build something pictured below (i cant post links yet ) and have it be able to be less than 30 cm but can extend over 30 cm in length?
**

First a little background information. I’m making a remote controlled robot that needs to fit in a 30x30x30cm box with no top or bottom. Box weighs 4~5 lbs. I need to pick the same box up and lift it then place it back down over objects.

To lift the box my idea is to make a gripper. It has to be less than 30cm in length but then extend over 30cm to grab the box. I’m thinking it would look kinda like this ( i cant post links yet)

Then to lift the box (only need to lift it about 3-4 inches from the ground) I’m thinking of putting the gripper on a little forklift or would it be easier to have the gripper be able to tilt.

Lastly, how would i go about making this gripper do i use 2 sets of rack and pinion gears one for each side?? I have no idea any input would be great.

Extra information about regulations:
Each robot circuit must be energized by one or more commercial batteries which do not exceed 9.6 volts. If multiple batteries are used, they may be connected in series or parallel as long as the voltage output does not exceed 9.6 volts. The voltage stated on commercial batteries will be accepted.
Each robot function (such as drive train, arm, etc.) may have its own independent circuit, source of electrical energy, and control mechanism.

So is 9.6 volts the max i can use?

Need to see a pix, but consider a scissor jack on each side to lift with? Use a small DC motor on 7.2v, which is a comfortable battery size. Limit switch on each end of travel.

Alan KM6VV

Sorry i forgot to mention some stuff like the box has no top or bottom and it wieghs around 5lbs let me edit it into the original post

Interseting project. The real-world vehicle that is similar to this is a front-end loader garbage truck like this:

ci.west-memphis.ar.us/pictur … Loader.jpg

Note the “linear actuator” that controls the arms. I would build exactly that on a smaller scale.

Of course you’re going to have to come up with a solution for gripping it if the sides are smooth… the loaders rely on channels in the dumpsters to slide its “arms” into. I’d consider having the “arms” slide under the edges of the box; otherwise, it’s going to slip unless you can come up with a way to apply a significant lateral force as well.

How high do you have to lift it?

I think you nailed it. “Lift the Box”. Better to use a front-end loader of some sort. A bucket-type front end-loader might work well. No clamping action needed.

The linear actuator could be a captive nut, with a continuous turn R/C or small DC motor turning a threaded rod. Acme threads would be best, but standard threaded stock (hardware store) should be fine. A limit switch at one end, and count the turns made.

Alan KM6VV