The gear is going to be fairly fragile on most 3D planes.

That is why I suggested that you look at a foamy, or something without landing gear.

While you can attempt to re-inforce the undercarriage, the problem is that the surrounding frame will also be lightly built.

You may want to also look at potentially hand launching your planes, and landing on the grass w/o gear.

This will require preping the fuse to take the abuse.