Fit Ladder
A small print before the big print.
Measured a round peg? Make a set of test holes, then find the fit on your printer. No account. Your measurements stay in this browser.
Your test plate
Live model previewPlate footprint—
Hole range—
Print orientationFlat, dots facing up
Match the dots
More dots = a larger hole.
| Dots | Hole Ø | Diametral clearance | Gap per side |
|---|---|---|---|
| Your size table will appear here. | |||
Hole diameter = peg diameter + diametral clearance.
From screen
to test piece.
A model dimension is a starting point, not a promised printed fit.
Keep the size table
Screenshot or print this page. Count the recessed dots on each coupon to find its model diameter. The dots are 1.4 mm wide and 0.5 mm deep; check they survive your slicer’s preview.
Slice in millimetres, at 100%
STL has no built-in unit setting. Import as mm, keep the pieces flat with the dots up, and check the footprint fits your bed. Do not auto-scale to fit. The pieces are separate closed solids in one file; you can rearrange them.
Match your intended print
Use the material, nozzle, orientation and slicer settings you intend to use for the final part. Review the sliced holes, base and dot recesses before printing. This tool does not choose those settings.
Compare gently, then verify again
Try the actual peg in each cooled coupon without forcing it. Record the useful hole size. Check the final geometry too: a result from this short vertical hole does not predict a long bore, horizontal hole or different material.
What the numbers mean
For coupon i, starting at zero:
hole Ø = peg Ø + first clearance + (i × increment)
A 0.2 mm diametral clearance gives a nominal 0.1 mm gap on each side of a centred peg. This is not 0.2 mm on each side. A zero-clearance model may print too tight.
Small, explicit geometry choices
Each hole is a 192-sided polygon around the nominal circle: the narrowest opposing-facet width equals the requested diameter. The largest vertex-to-vertex width is slightly larger.
The preview will report that small faceting difference for your model.
Each coupon keeps at least 3 mm of model wall around its main hole. Dot recesses identify coupons without tiny embossed text. Minimum wall and dot sizes are geometry choices, not a printer guarantee.
Why a test print?
Prusa’s modelling guide explains why fit depends on geometry, orientation, material and settings, and why testing matters. Existing approaches include a fit-dimension calculator and an OpenSCAD clearance-test generator. Fit Ladder’s mesh is original; it does not reuse those models or predict printer compensation.