Blueprints & Drawings

Figure 1 — The cover of Ralph Hagan's reproduction of the surviving Inland Manufacturing FP-45 factory drawing set. Source: survivorlibrary.com.

A builder needs dimensions, not descriptions, and the FP-45 is unusually well served: the actual 1942 Inland Manufacturing Division / General Motors factory drawings survive, in full, with real title blocks, material specs, tolerances, dates, and engineering-change tables. They are far better than any patent could be — and, as it happens, no patent exists (below). This volume walks the drawing set: where it lives, how it is organized, what each key sheet gives you, a dimension-reference table drawn strictly from the research, and how to translate 1942 drawings into modern CAD. It is the reference layer under Volume 6’s build.

7.1 No FP-45 Patent Exists — Say So

First, a correction to a natural assumption. There is no US patent covering the FP-45 Liberator. Extensive patent searching — Google Patents inventor/assignee searches for George Hyde, Inland Manufacturing, and Guide Lamp Division across 1942–45 — turned up nothing covering the Liberator pistol itself.¹ George Hyde does hold other real firearm patents (a 1936 patent for the Hyde Model 35, predecessor to the M3 “Grease Gun,” and a WWII-era rifle patent, US 2,376,057), but those cover the Grease Gun and a rifle, not the Liberator — do not cite a Hyde patent as the Liberator’s.² This absence is consistent with the FP-45 being a classified, deliberately obfuscated wartime government project (the cover-name scheme, below) that would have had no reason to run through peacetime patent prosecution. UNVERIFIED: no FP-45 patent was found; treat it as likely nonexistent rather than hunting a number that is not there. The factory drawings are the real, and better, source.

7.2 Where the Drawings Live

The drawing set was reproduced in Ralph Hagan’s 1996 book The Liberator Pistol: Development, Production, Distribution, and a scanned PDF of it is hosted, with Hagan’s permission per its own credit page, at:

https://www.survivorlibrary.com/library/liberator_pistol_blueprints.pdf — read directly in research, ~20 pages.³

It opens with a courtesy/credit page (crediting Ralph Hagan and biggerhammer.net), then a part-nomenclature-to-drawing-number cross-reference table, then the individual dimensioned, toleranced factory drawings themselves — genuine GM/Inland title blocks, material specs, dates starting May 1942, and engineering-change tables. Use it directly, with credit to Hagan, rather than redrawing from scratch. Mirrors exist (Scribd copies) for redundancy against link rot, but the survivorlibrary PDF is the directly-verified source.⁴

Acquiring Hagan’s physical book is worth it if you want the full production narrative alongside the drawings; no live current retail link for the book itself was found in research (the PDF’s credit page cites a now-defunct purchase page).

7.3 How the Set Is Organized

The drawings are numbered 13108 through 13133+, with 13133 itself an index of the drawings. The set covers all ~23 numbered parts. The key organizing feature for a modern reader is the wartime cover-name scheme — the drawings use euphemisms to disguise what was being built, and you have to translate them:

Table 1 — The drawings are numbered 13108 through 13133+, with 13133 itself an index of the drawings. The set covers all ~23 numbered parts. The key organizing feature for a modern reader is the wartime cover-name scheme — the drawings use euphemisms to disguise what was being built, and you have to translate them

Cover name on drawing	What it actually is
Tube	Barrel
Yoke	Trigger
Yoke Lever	The cam that acts as the sear
Control Rod	Firing pin / striker
Spanner	Trigger guard
Snap Cover	Magazine/grip door

The full nomenclature-to-drawing-number cross-reference is on the parts-list page of the PDF.³ Read that page first; it is the map to everything else.

Figure 2 — The parts-nomenclature / cover-name cross-reference page from the factory drawing set — the map that translates "tube," "yoke," and "control rod" into real parts and drawing numbers. Source: surviv… — Figure 2 — The parts-nomenclature / cover-name cross-reference page from the factory drawing set — the map that translates "tube," "yoke," and "control rod" into real parts and drawing numbers. Source: survivorlibrary.com.

7.4 The Dimension Reference Table

The following is drawn strictly from the research’s reading of the drawings — it is illustrative, not exhaustive, and the full PDF has the complete set. Every value here is from the factory drawings as reported; pull the actual sheets before cutting metal, and mark anything you cannot confirm on the sheet as uncertain.

Table 2 — The Dimension Reference Table

Part	Dwg #	Material / spec	Key dimensions
Tube (barrel)	13110	C.R.S., seamless	4″ long; stepped OD from 11/16″ dia. down to .135–.144″ dia. at muzzle; .0222″ included taper per inch over the taper
Tube & Strap Assembly	13111	C.R.S.	barrel OD ground to .4715–.4740″ over the strap-bearing section; arc-welded strap joint
Grip L.H./R.H. Assembly	13108 / 13108–13109	C.R.S.	projection-welded rivet-yoke and rivet-lock bosses
Yoke (trigger)	13113	C.R.S., GM 1010 spec	pivot-hole .188/.281″ referenced dims; 1-3/8″ overall
Yoke Lever (“sear” cam)	13114	C.R.S., GM 1010, case .004–.008″	cam profile from four blended radii (.032R / .075R / .150R / .125R) — a flat cam follower, not a hooked sear
Yoke Spring	13115	Music wire, stress-relieved	~3/4″ arm; 20° working range; 2.5 lb max load; must not take permanent set
Lock Spring	13119	Music wire, stress-relieved	6 coils, left-hand wound, over a 3/16″ dia. rod
Control Rod (firing pin)	13120	Cold-drawn wire, cyanide case-hardened .002–.006″ deep	2-1/16″ to first step; .062–.064″ drilled hole, central
Control Rod Assembly	13124	Zinc die cast body + steel guide pin	guide pin 13124-1 is C.R.S., .125″ ±.002″ dia.
Snap Cover (mag/grip plate)	13112	C.R.S., half-hard 1010	full-scale sheet-metal bend part
Shoulder Rivet / Rivet Yoke / Rivet Lock / Collar Pin	13116 / 13117 / 13118 / 13123	C.R.S. / steel wire (75,000 psi min tensile)	simple turned or wire-formed fasteners

Three of these sheets deserve to be pulled and studied directly, because they are the parts a build lives or dies on:

Tube, 13110 — the barrel. Note this is the smoothbore original geometry; a lab build substitutes a rifled blank (Volume 6) but the length, OD steps, and breech register transfer.
Yoke Lever, 13114 — the four-radius cam that is the fire control. Machine this to the drawing.
Control Rod, 13120 — the striker, with the central hole and case-hardening depth.

Figure 3 — Factory drawing 13110, the "Tube" (barrel) — 4-inch seamless C.R.S. with stepped OD. A lab build keeps the external geometry and substitutes a rifled bore. Source: survivorlibrary.com.

Figure 4 — Factory drawing 13113, the "Yoke" (trigger). Source: survivorlibrary.com.

Figure 5 — Factory drawing 13120, the "Control Rod" (firing pin) — cold-drawn wire, case-hardened, with a central striker hole. Source: survivorlibrary.com.

7.5 Translating 1942 Drawings Into CAD

A few practical notes for turning these sheets into modelable geometry:

Read the title block and change tables. Each sheet carries its material spec (GM 1010, half-hard, case-hardening depths) and a revision history. The material and heat-treat callouts matter as much as the geometry for a firing build — capture them, then decide where to upgrade (Volume 6: 4140 over the original low-carbon C.R.S.).
Translate the cover names as you go. Model the “tube” as a barrel, the “control rod” as a striker; keep a translation legend in your CAD project so the assembly reads correctly.
Treat the smoothbore barrel as the one deliberate deviation. Everything else you copy faithfully; the bore you change to rifled, and the chamber you re-cut straight and correctly headspaced (Volume 6). Model the barrel with the real external steps and a rifled bore of the correct .45 caliber and 1:16″ twist.
Rebuild tolerances for the joint that matters. The original’s loose tolerances are a stamping artifact (Volume 5). Model the breech joint to your tight headspace and heavier cross-section, not the drawing’s slop — the drawings give you shape and datum; you supply the modern fits at the breech.
Use the display STLs only for gross shape. The Thingiverse/Cults3D/MakerWorld models (Volume 3) are useful to sanity-check overall proportions and the cam/striker envelope, but they are non-functional props with blocked chambers — every functional dimension comes from these drawings, never from a prop file.

With the drawings in CAD and the build paths from Volume 6 chosen, the last piece is sourcing and the buy-versus-build decision — Volume 8.

7.6 Bibliography

Google Patents inventor/assignee searches for George Hyde, Inland Manufacturing, and Guide Lamp Division (1942–45); no FP-45-specific patent found. https://patents.google.com/ ↩
George Hyde (gun designer). Wikipedia. https://en.wikipedia.org/wiki/George_Hyde_(gun_designer) — other patents (Model 35 / M3 lineage, rifle US 2,376,057), none covering the Liberator. ↩
Ralph Hagan, The Liberator Pistol: Development, Production, Distribution (1996), factory drawing scans. Survivor Library. https://www.survivorlibrary.com/library/liberator_pistol_blueprints.pdf — drawing numbers 13108–13133, cover-name cross-reference, per-part dimensions and specs (directly read, ~20 pages). ↩ ↩²
Mirrors of the same set (not independently verified page-by-page). Scribd. https://www.scribd.com/doc/82639402/Liberator-Pistol-Blueprints and https://www.scribd.com/document/47284314/Pistol-Liberator-Blueprints-1942 ↩