Carbon fiber sheet is expensive, so every offcut is cost. But before talking about "how to raise utilization," set a realistic baseline: Hypertherm officially states that "typical nesting results are 70% material utilization and 30% scrap," and the best open-source algorithms reach densities of only 68.6% to 92.2% on standard benchmark sets. Any claim that "nesting software guarantees 95%" deserves skepticism.
The One-Minute Version
- The industry baseline is 70% utilization, 30% scrap (Hypertherm, official). Overall process waste in composites is about 20–30%.
- The academic ceiling is 68.6–92.2%: the density range of state-of-the-art algorithms on the ESICUP standard benchmark set, with a median of about 89%. When part shapes are complex (SHAPES0), even the best algorithm reaches only 68.6%.
- Minimum part spacing for CNC routing = tool diameter + clearance. Vectric's official example: 0.05″ clearance + 0.25″ tool = 0.3″. This is completely different from laser/waterjet spacing rules.
- Common-line cutting can save 12–40% of production time (measured by a Hypertherm customer), but we found no reliable source for how much material it saves.
- Common-line cutting has a physical limit on a CNC router: the kerf is the tool diameter, so two parts sharing one toolpath always lose one tool diameter of material.
- We found no reliable source for "automatic nesting beats manual by 10–15%"; if anything, research shows manual layouts consistently beating the commercial benchmark by about 4 percentage points.
Start with realistic expectations
Nesting software marketing often leaves the impression that "utilization can approach 100%." Here are the actual numbers:
Nesting utilization: industry baseline vs. algorithmic ceiling
Density range on academic benchmark sets, compared with industry practice and vendor claims
| Source | Figure | Type |
|---|---|---|
| Hypertherm (official) | Typical 70% utilization, 30% scrap | Official vendor statement; the most reliable baseline |
| sparrow open-source algorithm (KU Leuven) | 68.6% – 92.2% (13 benchmark instances) | Peer-reviewed; ESICUP standard benchmark set |
| Airborne (composites specialist) | Composite process waste about 20–30% | Vendor technical article |
| SigmaNEST | Most customers save over 4% material after switching | Vendor claim |
| Lantek | Raw material utilization up 8.2% | Vendor-reported customer result |
| JETCAM (composites) | Nesting efficiency stays above 90% | Vendor claim |
| "Automatic nesting beats manual by 10–15%" | No reliable source found | If anything, research shows manual layouts beating the commercial benchmark by about 4 percentage points |
| The last row is worth noting: a 2015 paper found that manual layouts by crowdsourced online workers "consistently beat the commercial benchmark by about 4 percentage points." When discussing the benefits of automation, programming time and consistency are a more defensible angle than utilization. | ||
Part spacing: CNC routing rules are completely different from laser
This is the rule most often misapplied. Laser and waterjet spacing is calculated as "a multiple of the kerf width," but on a CNC router, the kerf is the tool diameter, so the rule is completely different.
| Process | Part spacing | Sheet edge margin | Kerf width | Source |
|---|---|---|---|---|
| CNC router | Tool diameter + clearance | Margin + clearance + tool diameter | = tool diameter | Vectric official docs |
| CNC (fixture-held) | Node spacing ≥ 0.400″ (10.16mm) | — | — | SendCutSend (official) |
| Laser | 0.03″ (0.76mm) | 0.25″ (6.35mm) on each side | 0.25mm | Xometry |
| Waterjet | 0.125″ (3.18mm) | 0.25″ (6.35mm) on each side | 1.02mm | Xometry |
| General (kerf-based) | At least 3–5x the kerf width | — | — | Xometry |
| Vectric's official example: 0.05″ clearance + 0.25″ tool diameter = 0.3″ (7.62mm). That works out to about 5mm with a φ4 tool and about 7mm with a φ6 tool. In other words, the smaller the tool, the tighter you can nest, an adjustable variable CNC routing has over fixed-kerf processes. | ||||
How tool diameter affects nesting density
The same batch of small parts, spaced for a φ6 tool vs. a φ3 tool
Common-line cutting saves time, not material
Common-line cutting lets two adjacent parts share the same cutting path. On laser and plasma it is a standard way to save both material and time, but on a CNC router it calls for caution.
| Item | Data | Source and notes |
|---|---|---|
| Production time reduction | 12% – 40% | Measured by a Hypertherm customer (Olympic Steel) |
| Actual common-line gap | 0.006″–0.012″ (0.15–0.30mm) | SendCutSend (official), varies by material |
| Percentage of material saved | No reliable source found | The widely repeated "utilization raised from 75% to 90%" figure traces to a page that returns 403 and cannot be verified |
| Limit on a CNC router | Kerf = tool diameter | Two parts sharing a toolpath always lose one tool diameter of material |
| SendCutSend even explicitly rejects common-line nesting files: "two parts sharing a cut path does not account for kerf, beam width, tool diameter, or waterjet stream width," and common-line files are sent back for revision. This shows common-line cutting has to be handled correctly in CAM software; it isn't just a matter of overlapping two lines in CAD. | ||
Physically, a φ6 tool has a 6mm kerf, so when two adjacent parts share one toolpath, 6mm of material still disappears between them. Compared with cutting each part separately, what you save is the time of one toolpath pass, not material. So on a CNC router, the value of common-line cutting lies mainly in shorter machining time, unlike on laser or plasma.
Another CNC-specific limit: SendCutSend requires CNC-milled parts to have less than 50% material removal, or parts tend to shift or break during cutting. Nesting to the absolute limit can actually make workholding unreliable.
How to nest small drone parts in practice
Now apply the principles above to specific parts. Take the small accessory parts of a 5-inch FPV build as an example:
| Part | Typical size | Sheet thickness | Nesting notes |
|---|---|---|---|
| Battery plate | 80 × 60 mm | 1.5–2 mm | Large area; use it as the backbone of the nest and place small parts around it |
| ESC spacer plate | 40 × 40 mm | 0.5–1 mm | Thin and small; tabs are mandatory |
| Antenna mount | 25 × 20 mm | 1–2 mm | Must be FR4 or G-10; cannot be nested in the same batch as carbon sheet |
| Camera mounting plate | 30 × 25 mm | 2 mm | Edge node spacing may not leave room for tabs; needs vacuum |
| GPS mount | 40 × 30 mm | 1.5 mm | Same as the antenna mount; keep it off carbon fiber |
| Landing gear pad | 20 × 20 mm | 2–3 mm | Small part; use vacuum + tabs as double insurance |
| The most common nesting mistake is putting parts of different materials in the same file. Antenna mounts and GPS mounts must be FR4/G-10 (carbon fiber blocks the signal), so they need their own nesting file and their own sheet. | |||
| # | Rule | Reason |
|---|---|---|
| 1 | First confirm that every part on a sheet is the same material | Antenna-related parts must be FR4/G-10 |
| 2 | Place large parts first, fill gaps with small ones | Large parts have the least placement flexibility, so they need to be positioned first |
| 3 | Start spacing at "tool diameter + 1mm" | Per the Vectric rule, about 7mm for a φ6 tool |
| 4 | Leave an 8–10mm margin on all four sheet edges | For clamping and tool clearance, and to avoid uneven quality at the sheet edges |
| 5 | Always use tabs on parts under 30mm | Once cut free, the remaining area provides only a few kilograms of vacuum hold-down |
| 6 | Align critical edges with the safe fiber-angle zone | Little delamination at 0–90°, worst at 135° |
Putting offcuts to use
There is another often-overlooked way to raise utilization: systematically using offcuts left from previous jobs. The composites nesting field has published real-world data:
| Approach | Material saved | Applicability to desktop machining |
|---|---|---|
| Nesting a single kit across multiple rolls | 2.7% | Production-oriented; less common on desktop machines |
| Nesting different orders together | 5.7% | Combine parts from several projects onto one sheet |
| Back-to-back nesting on the same roll | 4.4% | Place two consecutive batches of parts right next to each other on the same sheet |
| Systematic offcut reuse | Manufacturing yield up to 87.3% | Build an offcut library and cut small parts from offcuts first |
| Another concept worth knowing: the gap between "nesting yield" and "manufacturing yield" is usually 5–10%. An 85% utilization in CAM may come out at only 78% in practice, with the difference going to scrap, recuts, and clamping zones. | ||
When you outsource, the leftover sheet stays at the job shop, and you pay for the whole sheet. When you cut in-house, the offcuts stay with you. Keep what's left after cutting a frame, and next time you make small parts like ESC spacer plates or pads, cut them straight from the offcuts instead of opening a new sheet.
The practical method is simple: sort and store offcuts by size, and create matching "sheet size" presets in your CAM software. When nesting small parts, pick an offcut size first, and use a new sheet only if the parts don't fit.
FAQ
Is nesting software worth buying?
It depends on your volume. Research shows that manual nesting does not necessarily lose to commercial software on utilization (a 2015 paper found that manual layouts by crowdsourced online workers consistently beat the commercial benchmark by about 4 percentage points). The real value of nesting software is programming time and consistency: when you have many part types and frequent batches, automatic nesting saves a lot of manual layout time. In R&D, with few part types and small batches, nesting by hand is enough.
Why does my calculated utilization come out in the 60s?
First, confirm that you are calculating total part area ÷ total sheet area. If the parts have complex shapes with many concave corners, the 60s are actually normal: even state-of-the-art algorithms reach only 68.6% on the complex-shape benchmark case (SHAPES0). Also remember to exclude the sheet edge margins and clamping zone, which were never usable in the first place.
How small can part spacing go?
The physical minimum is the tool diameter: at the very least, the tool has to fit between two parts. The practical minimum is tool diameter plus a little clearance (Vectric's official example is tool diameter + 0.05″). But pushing it to the limit is not recommended: when spacing is too tight, the thin strip left after the first part is cut loses rigidity and tends to vibrate or shift while the second part is being cut.
Do small parts really need tabs?
It depends on whether you have vacuum. What holds the part in place once it is cut free? With a vacuum table, check whether the part's remaining area is enough: 1 square inch on a regenerative blower system gives only about 2 kg of hold-down force, which cutting forces can exceed at any moment. If you only have double-sided tape or clamps, a small part will almost certainly move the instant it is cut free. Tabs are the most reliable and cheapest insurance.
Can antenna mounts really not be nested with carbon sheet parts?
No, and that is not a nesting problem but a material problem. Carbon fiber's electrical conductivity along the fiber direction is about 3.6 × 10⁴ S/m, so at GPS and video transmission frequencies it behaves like a metal shield; FR4 is about 3.3 × 10⁻¹³ S/m, a difference of 17 orders of magnitude. Antenna-related parts must be FR4 or G-10, so they are a different sheet material and a different nesting file to begin with.
Sources
- Hypertherm, Nesting Software (typical nesting: 70% material utilization, 30% scrap). Accessed 2026-09-03. https://www.hypertherm.com/solutions/technology/cam-software/nesting-software/
- Hypertherm customer story, Olympic Steel (guaranteed minimum 70% utilization; common-line cutting reduced production time by 12–40%). Accessed 2026-09-03. https://www.hypertherm.com/resources/more-resources/customer-stories/olympic-steel/
- Gardeyn, Vanden Berghe & Wauters (2025), An open-source heuristic to reboot 2D nesting research, arXiv:2509.13329 (densities of 68.6%–92.2% on the ESICUP standard benchmark set). https://arxiv.org/html/2509.13329v1
- Vectric Docs, Nest Parts (minimum spacing = tool diameter + clearance; official example 0.05″ + 0.25″ = 0.3″). Accessed 2026-09-03. https://docs.vectric.com/docs/V10.0/Cut2DPro/ENU/Help/form/Nest%20Parts/
- SendCutSend, Nesting Guidelines (node spacing ≥ 0.400″; common-line gap 0.006–0.012″; common-line files rejected; CNC-milled parts must have under 50% material removal). Accessed 2026-09-03. https://sendcutsend.com/guidelines/nesting/
- Xometry, DXF Nesting Best Practices (spacing, edge margins, and kerf widths for laser/waterjet/plasma). Accessed 2026-09-03. https://www.xometry.com/resources/sheet/dxf-nesting-best-practices/
- Airborne, Making the Composites Cutting Room Highly Efficient (composite process waste about 20–30%). Accessed 2026-09-03. https://www.airborne.com/making-the-composites-cutting-room-highly-efficient/
- Plataine, Nesting Yield vs Manufacturing Yield (5–10% gap between nesting yield and manufacturing yield; offcut reuse examples). Accessed 2026-09-03. https://www.plataine.com/blog/nesting-yield-vs-manufacturing-yield/
- Vasantha et al. (2015), International Journal of Production Research 54(14):4104-4125 (manual layouts by crowdsourced online workers consistently beat the commercial benchmark by about 4 percentage points). https://strathprints.strath.ac.uk/54653/
- Zhu, Ming, Wang et al. (2021), Materials 14(18):5210 (CFRP electrical conductivity tensor). https://pmc.ncbi.nlm.nih.gov/articles/PMC8467610/
Load full standard carbon sheets directly and skip the cut-down step
The Carbon Pro's 510×760mm travel accommodates commercially available standard carbon sheets of 400×500 and 500×600mm, so you can nest and machine them directly without cutting them down first. To talk through how to nest your part mix for the least waste, contact us with your drawings.
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