Two-Part Mold for Figurine Arms and Legs | RUUIPON
Posed arms against the torso will not peel from a glove. Split or plug so limbs demold on their own axis. Structure first, Shore last. MOQ 20.
Kyler Yang · Founder7 min read
If a figurine's arms or legs sit against the body, a one-piece glove will tear at the armpit or oval the limb on the way out. The rubber has to invert through a hook. Raising Shore A makes that worse. The mold you want is a keyed two-part (sometimes a plug on a weapon or a crossed ankle) so each limb demolds along a peel vector that does not fight the torso. Hide the seam on a belt, a hair part, or a cloak edge — not across the face. Jacket a 10A–20A skin so the pose does not sag. This is a structure problem, not a "stronger silicone" problem.
RUUIPON builds keyed platinum figurine tools in Bao'an since 2018. Prototype is 3–7 business days after CAD lock. Production is MOQ 20 pieces per design. Simple 3D is USD $50 when that CAD scope applies. Live figurine slug: custom figurine molds. Sculpture explainer: sculptures. LSR mascots as *parts*: wydsilicone.com.
Does not apply when the character is a one-sided relief on a plaque (open-back), when arms are sculpted *away* from the body with honest draft, or when you will cast the limbs separately and glue them. Jewelry-scale charms and concrete garden gnomes use the same limb logic; they are not food.
Why arms against the torso fail
The gap between arm and ribcage is a rubber web. On demold that web is a tear coupon. Confirm: a flap of RTV left in the armpit, or a limb that comes out banana-shaped. Fix: parting through the gap so each half peels off the outside of the arm, or a removable plug for a fully enclosed loop (arm akimbo with a closed window).
Legs that touch in a stance are the same coupon at the knees. Crossed legs often need a plug or a third piece. Weapons across the chest are cores.
Parting line: walk the silhouette. Put flash where a paint line already exists. Give each half enough wall that opening does not rip the shut. Keys are drafted cones, not mushroom pips in a 10A flange — torn keys are a cousin failure.
Pour gate at a foot or a hidden back. Vents at hair and fingertips, the last places air sits. A pressure pot on *your* resin does not fix a glove that already tore.
The photo that would prove the tool is an open two-part with the arm fully in one half, keys unmarked, and a witness resin with flash on the belt. A glove inside-out around a posed STL is the failure photo.
Typical shop values
Caption: Typical shop values.
| Item | Typical shop value |
|---|---|
| Structure | Keyed two-part; plug if a closed window |
| Skin Shore | 10A–20A; jacket takes pose |
| Keys | Drafted, filleted, real female wall |
| Mix / shrink | platinum 1:1 or 10:1; ~0.1–0.3% |
| Sag without jacket | about 0.5–1.5 mm on a tall wet dump |
| Prototype | 3–7 business days after CAD lock |
| Production | MOQ 20 pieces per design |
| CAD | USD $50 when we still model the split |
| Drawing class | ISO 3302-1 M2 unless the print says otherwise |
Common mix-up: raise Shore so the arms just pop
A 40A glove on a posed mascot locks resin in the fists and still tears at the armpit. The cousin mix-up is posing the STL for a pretty render with arms glued to the hip, then asking for a production glove. Sculpt a demold gap or accept a split. Another: cutting a block after cure to "find" a seam through the face because the CAD had no parting.
Worked example (anonymized)
80 mm resin mascot, arms folded, staff across the body. Buyer asked for a glove in 30A. We refused the glove, charged USD $50 to put a belt-line split and a staff plug in CAD, platinum ~15A, jacket, drafted keys. Proto 3–7 business days after lock. Production MOQ 20 of that revision. Craft resin, not food. A version with arms held away from the torso could have been a simpler split without the plug.
We would not recommend
We would not recommend a one-piece glove when arms or legs rest on the torso.
We would not recommend raising Shore A as the first move on a posed limb.
We would not recommend mushroom keys on the flange of a 10A figurine skin.
We would not recommend a food pack on a resin mascot tool.
flowchart TD
A[Figurine pose] --> B{Arms or legs against the body?}
B -->|no, honest draft gap| C[Simpler split or even open-back relief]
B -->|yes| D[Keyed two-part — limb in a half, not a glove]
D --> E{Closed window / weapon loop?}
E -->|yes| F[Add removable plug]
E -->|no| G[Jacket if wet/tall]
F --> G
G --> H[CAD lock → 3–7 days → MOQ 20]What to ask when you're buying a posed figurine tool
- Can we move the pose, or is the locked art arms-on-torso?
- Seam on belt/hair, not face?
- Plug for staff/loop, in CAD?
- Jacket yes/no for the dump mass?
- Resin/plaster/concrete (not food)?
Related: split lines, inner core, contact.
RFQ copy-pack — limbs as a structure line
Email [email protected]:
Pose: arms/legs against body / gap exists Dump: resin / PU / plaster / concrete — not food Structure: two-part required if limbs touch; plug if closed loop Seam preference: belt / hair / cloak Keys: drafted in CAD Platinum 1:1 or 10:1, vacuum, jacket if wet CAD: USD $50 if you model the split Prototype 3–7 business days after CAD lock, then MOQ 20 / design Do not quote a glove for arms-on-torso
Send the pose and the dump. We will split so limbs leave, we will not "make the rubber stronger." Phone +86 135 3006 2969. Xinhe Blvd, Shajing, Bao'an, since 2018.
FAQ
Can you just use really soft silicone so the arms stretch off? A 10A glove still tears at a closed armpit or oval the limb. Softness is for peel of *drafted* undercuts, not for ignoring a hook.
Should I sculpt the arms separately? That is a valid production choice: two simple tools plus assembly. Compare that cost to one two-part plus plug. MOQ 20 applies per design.
Where should the seam go on a nude figure? Still on the least-visible equator. We will not hide flash by raising Shore. You may need to accept a fine seam or change the pose.
Do I need a jacket for a 80 mm resin mascot? Often a board or a light jacket keeps the split shut. Tall wet plaster gnomes need a real mother mold. Sag bands of 0.5–1.5 mm show up as thick limbs on one side.
If the proto glove already tore, is that the locked design? No. We remake as a two-part revision. Production MOQ 20 is of the locked split, not of the torn glove.
Demold sequence for limbs so you do not invent a third tear
Open the jacket first. Break the rubber parting at the designed lip, not at a fingertip. Peel each half off the *outside* of the arm; do not pull the casting as if it were a glove pop. If a fist is still trapped, that is a missing plug or a missing vent, not a reason to twist the wrist. Wait until the resin has enough green strength that a 10A–20A stretch does not leave fingerprints — and not so long that a brittle PU snaps at the ankle.
Paint-ready flash on a belt sands; flash on a cheek does not. If T1 shows face flash, we move the seam on a CAD revision, we do not "flash less" by mixing extra B. Mix stays 1:1 or 10:1 by weight. Platinum shrink ~0.1–0.3% is on the master, not a reason to squeeze the split harder.
A concrete garden character uses the same limb split plus a jacket for wet kilograms. A lost-wax jewelry figure at 20 mm uses the same logic at smaller keys. Neither dump inherits a food extraction pack.
ISO 3302-1 M2 will not pose the STL for you. Tooling charge is not a free second character if the art director glues the arms down again.
Licheng Technology Industry Park, Xinhe Blvd, Shajing, Bao'an, since 2018.
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