Duplo compatible cart with couplers and wheels

I couldnt find a duplo cart that had any couplers. My kids like to play with Duplo trains. Added couplers and adjusted the wheels to a decent fit. The original model didnt have couplers nor did the wheels fit properly. 

You might want to add a small support to the female coupler. Mine printed fine without it, but not every printer might like it. 

The original duplo cart didnt have any couplers and the wheels were too wide. Adjusted the wheels to a correct size an added the couplers to make this compatible for train like playing.