It would be nice to have the ability to build tool holder assemblies as this is very common in the manufacturing industry. Currently you can only add a holder to a cutting tool, but it would be nice to add a holder to holder or add a second holder to the tool. such as an ER16 or shrink-fit extension to another holder. currently I am modeling the holders up, but I have to create a new holder or modify the existing holder if I want to extend it farther out or move it in. below is an example of a modeled tool. in the case I have an ER11 extension holder in an ER32 Holder. I have more complex examples to with the boring heads and arbors.