In this page, instructions of the PTW motor modification to fit to PTW HK417 is explained.
■OVERVIEW■
Lower receivers of the PTW M4s have mechanical structure for fixing a PTW motor. However, of course, the VFC HK417 GBB dose not have one. Therefore, you have to design and make a motor mounter for the PTW motor fixing into the VFC HK417 GBB lower receiver.
■STEP1: VERIFYING PROBLEMS TO FITTING THE PTW MOTOR INTO THE VFC HK417 GBB■
Lower receivers of the PTW M4s have mechanical structure for fixing a PTW motor like as Fig.1. However, the lower receiver of the VFC HK417 GBB dose not have one. Real AR rifles and M4 GBB rifles have a grip mounter in this spot, so you think like that "Is solution additional machining of holes and a slot?". Unfortunately, it is not (; 'A`)
Fig.1 Mechanical structure of the PTW M4 for fixing the PTW motor
A critical problem is that the lower receiver of the VFC HK417 GBB has an detachable grip mounter as shown Fig. 2. This grip mounter has three screw holes. One hole is used for fixing a grip. Other two screw holes are used for fixing itself into the lower receiver of the VFC HK417 GBB. Latter two screw holes interfere in spring pin holes fixing the PTW motor. That means it is inappropriate for the lower receiver of the VFC HK417 GBB to additional machining.
A solution of this project is modifying the PTW motor base. That means developing a new motor base integrates the PTW motor base and the grip mounter of the VFC HK417 GBB.
■STEP2: DESIGNING THE MOTOR BASE■
As the solution of the problem, I had designed a new motor base as shown Fig.3
Fig.3 The new motor base for HK417 PTW