Custom Silicone Mold Design: From Sketch to Cavity CAD

You don't need a perfect CAD file to start a custom RTV mold. You do need enough information to define the finished dump: size or grams, pour chemistry, and whether the part can leave the cavity. RUUIPON's design service is that conversion - sketches, samples, reference images, or a rough STL into mold-ready geometry (split, logo depth in millimetres, cavity map, jacket yes/no) before anyone prints a pattern or casts a resin production mother. Custom/simple 3D modeling is USD $50 when that scope applies. Chargeable CAD starts only after that scope is confirmed. Complex organic rebuilds are quoted separately; we don't invent another number here.

Prototype is 3-7 business days after CAD lock. Production MOQ is 20 pieces per design. Shop: Bao'an since 2018. Related process pages: CAD from physical sample, DFM review, from photos. Catalog: process catalog. This is not an LSR part-design desk. Steel/LSR *parts* → ask us.

Where design work is actually needed

• The product exists only as a rendering or a sketch.
• A physical sample must be copied (calipers, not a cropped PDP).
• You have an STL but no split, no draft, no logo depth.
• Logo detail is too fine to demold - logo depth lock.
• A tray needs a piece weight but cavity volume is unknown - shrink and grams.
• Several sizes need a shared tray span.

These are DFM problems, not "make it pretty in CAD."

Common mix-up: $50 buys a week of sculpture reconstruction

The USD $50 line is custom/simple 3D modeling when that scope applies - turning measured photos or a rough file into a production-ready cavity model. It does not buy missing millimetres, a full organic rebuild from a blurry selfie, or ownership of every derivative file unless the PO says so. A tooling or design fee is not unrestricted CAD ownership.

What we review before the model is freeze-ready

Finished part dimensions; cavity volume / grams; draft; undercuts; split line; silicone thickness; support shell; logo depth in mm; vents; cavity spacing; tray outer size; demold direction. The goal is a cavity you can pour, not a render that matches the listing photo at the cost of a torn serif.

Typical shop values

Reference values only. Confirm material-specific limits against the supplier’s technical data and agree project acceptance criteria before production.

Failure: approving a grey render, then fighting the peel

Symptom: Listing photo had a hooked bail; CAD flattened it without KEEP/FLATTEN; grams off because volume was guessed from a crop; files "included" that you cannot take to a second shop.

Confirm: Was scope confirmed before the $50 line? Are units mm? Is there a KEEP/FLATTEN mark-up? Does the PO name file deliverables?

Fix: Stop the pattern. Reopen DFM. Write custody and STEP deliverable if you need them.

Worked example: bear tray from brand art, no STEP

A confectionery brand sent outlined art and a 4.0 g pectin target, no cavity map. Design service: USD $50 simple 3D for the 12-up map, DFM on island width, logo depth 0.4 mm recessed, jacket flagged for loaded sag. CAD lock, then a 3D-printed pattern, often a temporary silicone flip, a resin production mother, then a 3-7 day RTV prototype, then MOQ 20. A week of mascot sculpture would have been a separate reverse-engineering quote, not the $50 line.

What to ask when you're buying design

• Is this the $50 simple-model scope, or a separate reverse-engineering quote?
• Do I receive STEP at freeze, and who owns it?
• Will you mark KEEP/FLATTEN on undercuts before lock?
• Is logo depth in millimetres on the 2D?
• Does the prototype clock start at lock, or at the first sketch?

When this service is the wrong buy

If you already have a freeze-ready STEP, you need DFM and a pour quote, not a design package. If you need an LSR keypad CAD, that is a different RFQ - ask us. A catalog ice geometry that already matches doesn't need custom 3D. Geometry can override quantity: a one-off resin hook still needs split design.

Related: master options, RFQ checklist, contact.

RFQ: design-service pack

Copy this.

What you have: sketch / rendering / STL / sample / photos+scale Known dimension (mm) or target grams: Dump material + peak °C: KEEP or FLATTEN on hooked features: Logo depth mm / raised or recessed: Need STEP deliverable? yes/no Simple 3D at $50 in scope? yes / or quote reverse-engineering Then print pattern → (often) flip → resin production mother → 3-7 day RTV prototype, MOQ 20 Pattern type / flip used? / who keeps the resin production mother: Who owns CAD:

Send the files and the known millimetre. contact - [email protected] · +86 135 3006 2969. Ask us to confirm whether this is the $50 line - that's the CTA.

We would not recommend charging CAD before scope is confirmed

We would not recommend treating $50 as a week of sculpture. We would not recommend locking CAD from one unscaled beauty shot. We would not recommend a hooked bail on a one-piece cookie-tray pull. We would not recommend file ownership by silence.

RUUIPON Mold Structure Decision:

FAQ

Is CAD from sample the same as $50 modeling? CAD from a physical sample is the bench-caliper path. Custom/simple 3D is USD $50 when that scope applies. They can overlap; we confirm before invoicing.

Do I need design if I have STEP? Often no - send it to DFM. Design is for missing cavity geometry, split, or grams.

Who owns the CAD if I paid the design fee? Whatever the agreement says. Write it. A design fee is not unrestricted ownership.

Can you start from photos only? Yes, with a millimetre scale and four views. Fit-sensitive or gram-sensitive work still wants a sample or STEP before lock.

What's after design? CAD lock → 3D-printed pattern → (often) temporary silicone flip → resin production mother → 3-7 day RTV prototype, then MOQ 20 per design.