I just had to print at 1:1 scale using a standard printer and paste the parts of the rifle and ready I have all I need to do in sliced.
next step, calculate how many layers are needed for the rifle?, this was used to make 21 layers, each layer was 3mm thick.
next step is to copy the rifle figure equal to the number of layers to be used, it takes half of the 21 layers for only one side of the weapon, take 10 layers, one layer is always left untouched
next step take the rifle image printed and cut some parts to go drawing it in layers, one by one. I give you an example
the hardest part of making the rifle, was targeted was not really easy, it fetches many pictures but did not have a clear idea of how to do it.