Threads - Product Design Mold Design

Molded-in threads can be designed into parts made of engineering thermoplastic resins. Threads always should have radiused roots and should not have feather edges – to avoid stress concentrations. Figure 35 shows examples of good design for molded-in external and internal threads. For additional information on molded-in threads, see page 105. Threads also form undercuts and should be treated as such when the part is being removed from the mold i.e., by provision of unscrewing mechanisms, collapsible cores, etc. Every effort should be made to locate external threads on the parting line of the mold where economics and mold reliability are most favorable. 

Product Design Mold Design

Gears

Gear teeth are a repetitive feature similar to screw threads or splines. It is not necessary to show their full form. In non-sectional views, gears are represented by a solid outline without teeth and with the addition of the pitch diameter surface of a type G line. In a transverse section, the gear teeth are unsectioned whereas the body of the gear is. The limit of the section hatching is the base line of the teeth as shown in the drawing in Figure 3.17. In an axial section, it is normal to show two individual gear teeth unsectioned but at diametrically opposed positions in the plane of the section. All details of the gear type shape and form need to be given via a note. In a gear assembly drawing which shows at least two gears, the same principle as for individual teeth (above) is used but at the point of mesh, neither of the two gears is assumed to be hidden by the other in a side view. Both of the gears' outer diameters are shown as solid lines. The standard ISO 2203:1973 gives details of the conventions for gears. 

Engineering Drawing for Manufacture
by Brian Griffiths
Publisher: Elsevier Science & Technology Books
 

Tail stock or loose head stock

Tailstock is located at the inner ways at the right hand end of the bed. This has two main uses: 1) It supports the other end of the work when it is being machined between centers, and 2) It holds a tool for performing operations such as drilling, reaming, taping, e.t.c. To accommodate different length of work, the body of the tailstock can be adjusted along the ways chiefly by sliding it to the desired position where it can be clamped by bolts and plates. The upper casting of the body can be moved toward or away from the operator by means of the adjusting screws to offset the tail stock for taper turning and to realign the tailstock centered for straight turning. The body is bored to act as barrel which carries the tail stock spindle that moves in and out of the barrel by means of the screw when the tail stock handle is turned. The front of the spindle has taper hole into which the dead center or other tool fits. After the adjustment is made, the spindle is clamped in the position by tightening the locking bolt on spilt lug.

Container Design Extrusion Blow Molding

Performance Objective: Use design details that improve drop impact performance Radii: Long and Generous, especially around the base, to allow flash pinch terminations to be located up on container sidewall chime or within the base pushup Base Engravings: Shallow, with Smooth, Rounded Edges Base Shape and Pushup: Rounded and Shallow Footprint: Wide and Rounded with smooth transitions to base and sidewall Panels: wide sidewall panels with long radii Radii: long and generous everywhere, especially at the base to allow flash pinch terminations to be located up on container sidewall chime or within the base pushup Base Engravings: shallow with smooth rounded edges Base Shape and Pushup: Rounded and shallow Footprint: Wide and rounded with smooth transitions to base and sidewall Panels: Wide sidewall panels with long transition radii 

EASTMAN
Extrusion Blow Molding Presentation