A miniature or a display piece only needs to "look right". A jig, a snap-fit enclosure or a screw-retained part needs to actually fit. Resin printing has a reputation for shining on detail, but dimensional accuracy takes a little deliberate work. Here is the practical calibration flow to get true-to-size parts off your LCD machine with ANTINSKY Standard Lite Resin.
Step 1: build an exposure matrix first
Exposure time is the single biggest lever on feature size in resin. Print a small calibration matrix that varies the normal-layer exposure across eight to ten steps, using your normal bottom-layer settings. Let it cure, then inspect: under-exposed parts are soft and undersized on thin features; over-exposed parts "grow" because light bleeds past the mask, thickening walls and filling holes.
Where shrinkage really comes from
Photopolymers shrink as they cross-link during curing. Two things amplify it: excess exposure (more cure = more shrink) and poor stabilization before the next layer. Keep the build plate at a steady temperature, and keep over-exposure minimal — over-curing to chase detail usually makes a part smaller than the model, not crisper.
Step 2: measure with the tools that matter
- Measure the features your part actually needs — a bore for a shaft, the width of a clip. Don't obsess over the overall box dimensions.
- Check hole diameter and pin diameter separately: resin tends to close up holes and hold pins more faithfully.
- Record results at both X/Y and Z. Resin printers are usually close in X/Y but occasionally off in Z because of layer-adhesion height.
Step 3: dial in shrink compensation
| Observation | Likely cause | Fix |
|---|---|---|
| Part undersized overall | Over-exposure / over-curing | Lower normal exposure slightly |
| Holes too small, pins too big | Light bleed into masked areas | Reduce exposure; consider anti-aliasing off for mechanical parts |
| Z dimension tall/short | Layer thickness + lift settings | Verify layer height; reduce or add Z tollerance on the model |
| Soft, poorly cured surfaces | Under-exposure | Raise normal exposure in small steps |
Step 4: verify with a real joint
The theory only matters if the two halves actually mate. Print a press-fit or slide-fit test pair, wet-fit them, and adjust one variable at a time. Keep a small log — the number that worked for Standard Lite is usually very close across the Standard Resin and Standard Tough family, so your validation transfers.
Temperature is the silent variable
Resin viscosity (and thus effective cure) changes with temperature. If the room drifts between spring and summer, re-run the matrix rather than guessing. A stable, warm print environment makes exposure settings repeatable — which is the whole point of calibration. Find Standard Lite Resin 1 kg and the rest of the ANTINSKY resin range at InnoStation 3D.