Week 9 - Attachment Feature Creation - Challenge 2

DOOR TRIM LOWER

Aim: To Create the Door trim lower component through the given Class-A surface.

Objectives:

• Creation of Tooling axis with appropriate draft angle.

• Creation of other surfaces (eg, B and C surfaces) for creating a solid component.

• Perform Draft analysis on Class A surface and Solid model hence created.

• create doghouse feature as the given design guidelines and perform draft anayslis on th feature

DRAFT:

• the draft is the amount of taper for the moulded or cast parts perpendicular to the parting line.
• Draft angle are in design consideration to make parts easly eject from the mold cleanly
• A draft angle are calculated degree measurement fron the vertical axis of mould
• without draft eject of the parts component compicated and wear and tear will occur in the mold which leads to shorten life time of the tool
• draft is important to overcome the vaccum force by letting the air between the metal and plastic components for parts release properly from the mold
• Draft angles are generally a requirement of injection moulding design (though there are a select few soft materials, like nylon, that can get away with draft angles of zero).
• By accounting for thermoplastic shrinkage during the cooling process, draft angles significantly reduce friction between the finished, cooled part and the side of the mould, Not only does this create a much easier release process
• Most, if not all, of these benefits, offer either direct or indirect overall production cost reductions.

tooling axis creation

it is the direction in which mould core / cavity opens

selection of the direction of the tooling axis depends on which components easily eject from th tool. by analysing the component the most easily direction of the component is z dierction

creation of the tooling axis using the A Surface of the component, extract from the a surface and introduce point on the surface using point option and draw line in z direction in which the compnent will and eject

CLASS A SURFACE

TOOLING AXIS

DRAFT ANALYSIS ON A SURFACE

Same steps are followed to get the draft analysis of the solid part as in Class A Surface

The nomial draft angle for the plastic component is 3 degree and for the b-side feature is 0.5 degree. so the 3 degrees is provided in the draft degree in the window colour scale and inside green bar show draft of the component above 3 degree and blue colour below the 3 degrees and orange represent below o degree and negative draft angle.below all the top faces and side faces of the component are green, while the bottom faces are orange . The line of demarcation between the green and orange faces is the parting line which divides the core and cavity halves. The solid model has cleared the draft analysis successfully as shown in the image below.

CLASS B SURFACE

CLASS C SURAFCE

SOLID SURAFCE

DRAFT ANALYSIS ON SOLID MODEL

B-SIDE FEATURE

DOG HOUSE CREATION

The dog house is an engineering feature used in the plastic trim design. Dog houses are used as a supporting feature. Sometimes other engineering features like snaps; locators, etc. are mounded on them to increase their strength.

The doghouse is created by following the design rules.

The nominal wall thickness guide range is from 0.75 mm to 3 mm for reinforced materials and 0.5 mm to 5 mm for unreinforced materials.

Related Courses

WALL THICKNESS (W) = 0.70 (NOMINAL THICKNESS OF PLASTIC MATERIAL)

This process is usually done by Thicken surface command.

The fillets and the draft are given as per the design rules.

An important thing while designing a doghouse is to maintain 40% less thickness than the wall thickness (T) at the area of the intersection to avoid sink marks. So, a C shape is formed at the intersection.

the height of intersection point is inbetween 3 to 6mm

This can be made using the split command to remove the solid at the intersection

Draft anaylsis on dog house

creation of tooling axis for the dog house , the line is drawn on the four side of the surface by using the bisecting method the the one tooling axis of the doghouse is created, which clears the all surafce of doghouse and the nomial draft angle for the doghous is 0.5 degree