select
navigate
switch tabs
Esc close

Draft angles for master model?

0
P
3

hi, I’m designing the master model for a silicone mold (for vacuum casting) and wondering about the necessity of incorporating draft angles. Is it always required to include draft angles in the design, or are there specific cases where the material properties, mold complexity, or part geometry allow for skipping them? These holes in a cutaway detail are a good example, should I draft or not draft? thank you

Solved by Rafael Angulo
They’re only important if the next stage is a plan to go to more rigid, higher production capacity methods. Injection molding demands thorough care with draft angles to enable smooth ejection. Building them saves time for knock-on design changes later. Your model would closely match the final part. For a prototype or one-off design, they’re basically of no value. Silicone molds are so flexible they allow you to focus on part function without worrying about extraction. However, where a part’s geometry has deep or sharp features, adding draft angles might extend the mold's service life by reducing stress.
    • P

      hi, I’m designing the master model for a silicone mold (for vacuum casting) and wondering about the necessity of incorporating draft angles. Is it always required to include draft angles in the design, or are there specific cases where the material properties, mold complexity, or part geometry allow for skipping them? These holes in a cutaway detail are a good example, should I draft or not draft? thank you

      0
    • R

      No, draft angles aren’t strictly necessary when vacuum casting in silicone molds, but they might help in these long draws if you drill to parallel after casting. The flexibility of silicone means it can handle undercuts and intricate geometries without the need for any consideration of draft angles. This makes it easy to create complex shapes that would otherwise need much more complexity/processing in rigid molds.

      0
      Reply
      • P
        Rafael Angulo

        thanks. In what situations would you recommend adding draft angles?

        0
        Reply
      • R
        Pete Read

        They’re only important if the next stage is a plan to go to more rigid, higher production capacity methods. Injection molding demands thorough care with draft angles to enable smooth ejection. Building them saves time for knock-on design changes later. Your model would closely match the final part. For a prototype or one-off design, they’re basically of no value. Silicone molds are so flexible they allow you to focus on part function without worrying about extraction. However, where a part’s geometry has deep or sharp features, adding draft angles might extend the mold’s service life by reducing stress.

        0
        Reply
Draft angles for master model?
Your information:




Suggested Topics

Topic
Replies
Views
Activity
Cracking at snap-fit hook base in SLS PA12
Hello everyone, I'm using SLS 3D printing (PA12, 0.12 mm layer height) to create a snap-fit enclosure for a handheld sensor device. The enclosure has three internal hooks that flex about 1.5 mm during... read more
F
0
15
May 21
Choosing sheet metal thickness for a lightweight bracket
Hey, working on a small mounting bracket for a consumer electronics housing, cut and bent from stainless steel sheet (304 or 316). The part needs to stay under 200g, but it also has to... read more
D
0
53
May 13
Visibility of parting line on GF30 PA6 injection molded handle
Hello everyone, how visible can the parting line be on final molded parts? My team is currently designing a handle cover for an industrial machine, injection molded in PA6 with 30% glass fiber. Aesthetics... read more
T
C
1
72
May 06
Minimum embossed text size for TPU molding
Hey there, I'm designing a flexible watch strap that will be injection molded in TPU (Shore 85A). I want to include some small embossed text (branding and serial number) directly on the strap, but... read more
A
n
2
129
May 05
Printed bracket cracking – how to reinforce?
Hi,  I'm prototyping a small bracket for holding a plastic cover in place—roughly 60 × 30 × 10 mm, with two hooks and two screw holes (M3) on the top side. I printed it in PLA with 20% infill... read more
G
R
1
133
Apr 23