A wholesale buyer is on their fourth revision of a solitaire CAD. Round one moved the head up 1 mm, round two widened the shank, round three shortened the gallery, and round four re-sized the seat for a different moissanite. The factory has flagged that the next round is billable and the buyer is frustrated. The reality is that revision rounds are not unlimited courtesy; each one is a 5 to 7 day CAD rerun, a re-render, a resin print check, and a new spruing plan. The question is not how many revisions are reasonable, but which changes belong in which round.

How many revision rounds are normal

Our standard custom workflow includes two free rounds on every design. Round one is for proportions: head height, shank width, shoulder angle, gallery length. These are changes a designer can make by re-dimensioning parameters without re-modeling. Round two is for stone fit and wear details: seat size measured to the actual girdle, comfort-fit interior, engraving placement, and flange for the wedding band. After that, CAD revision cycles for clients become billable at a posted rate, because the model is no longer moving inside its original parameter tree.

Buyers who arrive with a reference photo, a stone spec sheet, and a sizing chart usually close after round two. Buyers who arrive with make-it-look-expensive usually land at round four. We show both paths in the onboarding quote so the expectation is set before the first render.

What changes actually cost at the model

Not every CAD change is equal. Moving the head height or widening the shank is a parameter edit, 1 day. Re-sizing the seat for a different stone means re-cutting the basket, re-spruing the wax, and re-checking under-cut, 2 days. Changing the head from prongs to bezel is a new model, not a revision, and we price it as a fresh design. We also enforce factory CAD tolerances: undercuts, wall thickness, and seat depth cannot drift between rounds, or the casting will fail even if the render looks identical.

The export stage matters. CAD export settings for casting decide whether the STL prints cleanly on the wax machine; a revision round that changes export settings re-runs the print validation even if the geometry barely moved.

The approval gate before wax

Once the buyer signs the render, we print a wax, photograph it next to a ruler and the actual stone, and send one more photo for approval. No CAD changes happen after that photo. This is the gate. Custom ring wax prototypes before production exist because a 0.3 mm head height difference reads fine on screen but wrong on the finger; the wax catches it, and the CAD does not.

We also send the factory CAD file requirements checklist with the first render: unit system, wall minimum, seat depth, and spruing points. Buyers who fill that checklist themselves cut revision time by half, because the model already matches what the casting bench needs.

File naming and version control on our side

Every revision round gets a version tag: ringname_v1, v2, v3, and so on. We do not overwrite earlier renders, so a buyer who liked round two but wanted round three proportions can go back without re-explaining. We also keep the STL export from the approved render, not from the latest parameter edit, which means casting uses the exact geometry the buyer signed. When a custom order runs alongside a repeat, we tag the CAD file with the PO number and the buyer resale name so the casting bench never pours the wrong version. For buyers sourcing stones themselves, we measure the actual moissanite or diamond girdle in-house and feed that number back into the model before final render; lab-grown diamond girdles vary by lot, and a nominal 6.5 mm seat will not hold a 6.47 mm stone.

FAQ: Ring CAD revision rounds

How many CAD revisions does a custom ring need?

Most orders close in two rounds: proportions, then stone fit. Three rounds is common. Four or more usually means the reference brief was not clear at kickoff, and we price those as billable iterations.

Do you charge for revision rounds?

The first two are free. The third onward carries a posted per-round fee, because the model is being rebuilt outside its parameter tree. We show the fee schedule in the onboarding quote.

Can I change the stone size after the wax is printed?

No. The wax is printed to the measured girdle; re-sizing the seat means re-modeling and re-printing. If the stone is not final, hold the wax print until it is.

How long does each CAD round take?

Parameter edits: 1 business day. Re-modeling the head or gallery: 2 to 3 days. Full re-render plus wax validation: 5 to 7 days end to end.

Send over your reference photo, stone spec, and ring size. Our CAD bench ships renders within 3 days, includes two free revision rounds, and prints a signed-off wax before any metal is poured. Small-batch OEM custom manufacturing starts at 30 pieces per design; send the brief and we will map the revision path.

Frequently Asked Questions

What ring sizes can you supply in bulk?

US sizes 5–12 including half sizes. Send a size breakdown with your order and we cast to that curve; comfort-fit inner bands reduce resize requests.

Can I order a mixed size run instead of one size?

Yes. Mixed runs are standard for wholesale: specify quantity per size and we pack and label by size at no extra labor cost.

What is the MOQ for custom ring designs?

50 pieces per design for existing molds; 100–300 pieces when a new mold or CAD model is required.

How should I price rings for retail margin?

Most partners use a 3–4x markup on FOB cost for sterling and 2.5–3x for moissanite solos, which keeps landed cost under 30% of retail.