{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "trim-tabs",
 "name": "Trim tabs",
 "kind": "standard",
 "category": "Boat design",
 "group": "Hull types",
 "year": null,
 "question": "How do trim tabs work and what size do I need?",
 "tags": [
  "vehicle design",
  "hull types",
  "rc design",
  "aerodynamics"
 ],
 "aliases": [
  "trim tabs",
  "boat trim tabs",
  "rc trim tabs",
  "trim tab size",
  "trim tab angle",
  "bow down trim",
  "trim plates",
  "hydraulic trim tabs",
  "trim tab sizing"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 1,
 "url": "https://xemstudio.com/objects/trim-tabs/",
 "sheet_txt": "https://xemstudio.com/objects/trim-tabs/sheet.txt",
 "sheet": {
  "basis": "Design rules and figures from the cited sources; example geometry by Xem Studio",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Trim tabs are adjustable plates at the transom that push the stern up and the bow down, and can correct list (West Marine).",
   "West Marine's rule of thumb: at least 1 in of tab span per foot of boat length. On an RC mono, one builder runs tabs about 1-3 mm below the hull bottom (SV Design).",
   "The file is a reference example built by Xem Studio from the numbers above (1 x 1.5 in RC tab (SV Design); deflection illustrative.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle."
  ],
  "table": {
   "columns": [
    "parameter",
    "value or range",
    "source"
   ],
   "rows": [
    [
     "Span rule",
     ">=1 in per ft of boat length",
     "West Marine"
    ],
    [
     "RC tab drop",
     "1-3 mm below bottom",
     "SV Design (Stealthwake)"
    ],
    [
     "RC tab size example",
     "1 x 1.5 in metal tabs",
     "SV Design (Stealthwake)"
    ]
   ]
  }
 },
 "sheet_text": "Trim tabs — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/trim-tabs/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)\nBasis: Design rules and figures from the cited sources; example geometry by Xem Studio\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Trim tabs are adjustable plates at the transom that push the stern up and the bow down, and can correct list (West Marine).\n- West Marine's rule of thumb: at least 1 in of tab span per foot of boat length. On an RC mono, one builder runs tabs about 1-3 mm below the hull bottom (SV Design).\n- The file is a reference example built by Xem Studio from the numbers above (1 x 1.5 in RC tab (SV Design); deflection illustrative.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.\n\nparameter  value or range  source\nSpan rule  >=1 in per ft of boat length  West Marine\nRC tab drop  1-3 mm below bottom  SV Design (Stealthwake)\nRC tab size example  1 x 1.5 in metal tabs  SV Design (Stealthwake)\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- West Marine: Selecting and Installing Trim Tabs — web — Publisher's page; dimensions are facts — https://www.westmarine.com/west-advisor/Selecting-and-Installing-Trim-Tabs.html\n- SV Design: Pro Boat Stealthwake upgrades info (Feb 2022) — web — Publisher's page; dimensions are facts — https://myplace.frontier.com/~sv_design/Pro%20Boat%20Stealthwakes%20Upgrades%20Info%20SVC_Feb-2022.pdf\n\nFree files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/trim-tabs/index.json\nAPI: https://xemstudio.com/api/geometry?object=trim-tabs\n",
 "sources": [
  {
   "publisher": "West Marine",
   "title": "Selecting and Installing Trim Tabs",
   "url": "https://www.westmarine.com/west-advisor/Selecting-and-Installing-Trim-Tabs.html",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "SV Design",
   "title": "Pro Boat Stealthwake upgrades info (Feb 2022)",
   "url": "https://myplace.frontier.com/~sv_design/Pro%20Boat%20Stealthwakes%20Upgrades%20Info%20SVC_Feb-2022.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "free-files",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "deep-v-hull",
  "modified-v-hull",
  "flat-bottom-hull",
  "cathedral-tri-hull",
  "tunnel-hull-catamaran",
  "three-point-hydroplane"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "How wide?",
   "a": "At least 1 in per foot of length (West Marine)."
  }
 ],
 "files_license": {
  "name": "Xem Studio Design License",
  "holder": "Xem Studio",
  "url": "https://xemstudio.com/license/",
  "note": "Xem Studio's own design: free to use, print, modify and sell things made from it; not to be republished or redistributed as files."
 },
 "offers": [
  {
   "file": "trim-tabs-tab",
   "formats": [
    "step",
    "stl"
   ],
   "price_usd": 0,
   "license": "Xem Studio Design License",
   "step": "https://xemstudio.com/files/hardware/trim-tabs/trim-tabs-tab.step",
   "stl": "https://xemstudio.com/files/hardware/trim-tabs/trim-tabs-tab.stl",
   "note": "Hinged plate 38 × 25 mm deflected 5°"
  }
 ],
 "markdown": "https://xemstudio.com/objects/trim-tabs/index.md"
}