Replacement for a broken Echo PPS265T shaft coupling connector

I designed it a bit fragile and it didnt hold well under bigger loads, but the printing was right to the specs. The curved part to help guide the square shaft into the connector was too pronounced and ended up thinning too much the joint between the base and the main column, and that turned it into a really weak point. Exterior fits like a glove inside the main shaft. I didnt need to contact customer service (this is always great) as everything, from uploading, validation, payment, shipment and respect of the design was right according to what was advertised. The only mistake was mine, in my design, which I modified since. I will reorder accordingly !