ITERATION PLAYBOOK

Rapid injection molding factory path before steel

For a startup bridging 200 pieces, compare CNC, SLA, SLS, MJF, a 3D-printed tool and an aluminum tool against the same drawing before you accept a substitute. This page is a purchase-decision checklist, not an ESG statement, carbon claim, or net-zero story.

SLA print, CNC blank and aluminum mold insert on one bench

Specification choices that remain open on a 200-piece bridge

Geometry still moving?

If fit loops change weekly, SLA or MJF can hold envelope cheaper than recutting either a printed insert or aluminum. If you already need 200 molded pieces, a printed tool only helps when the bidder writes how many shots the insert may run before it is recut. Layer height, support-structure marks and annealing notes belong on the RFQ when additive parts are still in the mix.
Need production resin now?

CNC from ABS, PC, PA or POM bar stock can prove snap fits that printed resins will not, but it will not prove gate vestige. A printed tool may run production resin for a short window; aluminum usually holds melt temperature longer. Record Ra and ±0.025 mm features that must stay inspectable on the 200-piece lot.
Bridge to molding?

A rapid injection molding factory aluminum tool can return T1 with production-like gate vestige, ejector marks and texture. A printed insert can return a first cavity faster, then fail before piece 200 if the shot-count limit is missing. Ask for expected shot life, MUD versus standalone base, and whether T0/T1/T2 shots are included. Do not treat a class 105 or printed insert as class 101 without a written life assumption.
72-hour language

Express tracks are factory-specific. Write the target date as a request, not as a site-wide clock. If a bidder quotes 72 hours on a printed insert, ask which operations are excluded: texture, inserts, painting, FAI, and the second-insert reprint if 200 shots exceed the cap.

What to verify before accepting an alternative

CNC versus additive parts

CNC advocates cite production-grade materials and true mechanical properties. Additive-part advocates cite 24–48 hour loops and geometry that milling cannot reach. Those routes do not replace a 200-piece molded lot. If you accept MJF in place of molded ABS, write which tests are waived. If you accept CNC in place of a first tool, write which gate and knit-line risks remain untested.

Aluminum tool versus 3D-printed tool

Printed-tool advocates cite lower NRE and a faster first cavity while revision C is still moving. Aluminum-tool advocates cite a stabler shrink map, SPI texture, and a shot-life that more often covers 200 pieces in one cavity. Accepting either route as “good enough for launch” without a shot-count limit written on the quote is how a bridge insert becomes an unplanned reprint or an unplanned steel PO.

Route	Typical buyer check	Limitation to disclose
SLA	Cosmetic envelope, clip fit	UV aging and production resin mismatch
SLS / MJF	Living hinge screening, ducts	Surface roughness versus SPI texture
CNC	Snap fit in production polymer	No gate, no knit line, no mold shrink map
Printed tool	Fast first cavity, ECO-friendly insert	Shot-count often below 200 unless written
Aluminum tool	T1 molded parts, gate vestige	Shot-life and steel-upgrade trigger

Inspection method stays explicit: optical scan, CMM, or caliper-only. Build volume and layer resolution matter for additive parts; shot weight, clamp tonnage and the shot-count limit matter once a press is in the packet. None of those numbers are guaranteed by this desk.

Lock the 200-piece choices, then request quotes

State which process is required, whether an aluminum tool or a printed tool is allowed, quantity, destination and the first inspection pack. Optional budget and preference merge at submit time.

Name

Enter a contact name.

Work email

Enter a work email.

Phone (optional)

Company

Destination country

Inquiry type

Procurement requirements

Include specifications, quantity, destination and delivery timing. No existing quotation is required to start. After contact, send STEP/PDF drawings by the reply channel we confirm.

I have read the privacy policy.

Rapid injection molding factory path before steel

Specification choices that remain open on a 200-piece bridge

Geometry still moving?

Need production resin now?

Bridge to molding?

72-hour language

Files to request on a prototype path

What to verify before accepting an alternative

CNC versus additive parts

Aluminum tool versus 3D-printed tool

Lock the 200-piece choices, then request quotes