Pocket Roughing Time (by Volume)
Roughing time for a rectangular pocket from volume and achievable MRR.
Volume รท MRR is the most honest roughing estimate there is โ the efficiency factor absorbs lead-ins, repositioning and the corners a round tool can't fill. Adaptive/trochoidal paths hold efficiency near 0.85; old-style zigzag wastes 30%+.
Formula
Note: Catalog starting values only โ always confirm against your tool maker's data sheet and cut a test part. Machine rigidity, coolant and workholding shift real-world numbers.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates โ verify with a qualified professional before making decisions. Read the full disclaimer.
Roughing time for a rectangular pocket from volume and achievable MRR. A free cnc machining: speeds, feeds & tool wear tool โ no sign-up, no upload, instant results in your browser.
About Pocket Roughing Time (by Volume)
Pocket Roughing Time (by Volume) computes the governing relationship t = V / (MRR ร ฮท) live as you type. Volume รท MRR is the most honest roughing estimate there is โ the efficiency factor absorbs lead-ins, repositioning and the corners a round tool can't fill. Adaptive/trochoidal paths hold efficiency near 0.85; old-style zigzag wastes 30%+. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Pocket Roughing Time (by Volume)
- 1Enter your values โ Pocket length, Pocket width, Pocket depth, Achievable MRR and more (sensible defaults are pre-filled).
- 2Read the live results: Material removed, Roughing time.
- 3Check the "with your numbers" line to see t = V / (MRR ร ฮท) substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Pocket Roughing Time (by Volume)?
- โInstant, free and private โ every calculation runs client-side in your browser; nothing is uploaded
- โBuilt on the stated formula t = V / (MRR ร ฮท) with authoritative sources cited on the page (Machinery's Handbook, 31st ed. โ Speeds and Feeds; Kalpakjian & Schmid, Manufacturing Engineering and Technology, 7th ed., ch. 21)
- โVolume รท MRR is the most honest roughing estimate there is โ the efficiency factor absorbs lead-ins, repositioning and the corners a round tool can't fill.
- โSI โ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the pocket roughing time (by volume) use?+
It evaluates t = V / (MRR ร ฮท), exactly as published. Sources: Machinery's Handbook, 31st ed. โ Speeds and Feeds; Kalpakjian & Schmid, Manufacturing Engineering and Technology, 7th ed., ch. 21. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result โ and how far can I trust it?+
Volume รท MRR is the most honest roughing estimate there is โ the efficiency factor absorbs lead-ins, repositioning and the corners a round tool can't fill. Catalog starting values only โ always confirm against your tool maker's data sheet and cut a test part. Machine rigidity, coolant and workholding shift real-world numbers.
When is this calculator the right tool for the job?+
Roughing time for a rectangular pocket from volume and achievable MRR. A free cnc machining: speeds, feeds & tool wear tool. Adaptive/trochoidal paths hold efficiency near 0.85; old-style zigzag wastes 30%+. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes โ the SI โ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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