{"id":8080,"date":"2022-09-30T10:18:10","date_gmt":"2022-09-30T09:18:10","guid":{"rendered":"https:\/\/purplemeanie.co.uk\/?page_id=8080"},"modified":"2026-05-22T21:45:19","modified_gmt":"2026-05-22T20:45:19","slug":"projects","status":"publish","type":"page","link":"https:\/\/purplemeanie.co.uk\/index.php\/projects\/","title":{"rendered":"Projects"},"content":{"rendered":"<p>Purplemeanie is a long-running engineering notebook. Some of it is a build log, some of it is diagnostics, some of it is electric conversion work, and some of it is just the useful trail left behind when a problem takes a few evenings to understand properly.<\/p>\n<p>This page is a starting point for the technical parts of the site.<\/p>\n<h2>Caterham 420R Build<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828-600x400.jpg\" alt=\"Caterham 420R build archive representative photo\" \/><\/figure>\n<p>The Caterham 420R build archive covers the original kit build, post-build checks, setup, fixes, upgrades, and ownership notes.<\/p>\n<p>Start here:<\/p>\n<ul>\n<li><a href=\"\/index.php\/build-blog-index\/\">Build Blog<\/a><\/li>\n<\/ul>\n<p>Useful themes:<\/p>\n<ul>\n<li>build sessions and chronology<\/li>\n<li>IVA preparation<\/li>\n<li>mechanical setup<\/li>\n<li>wiring and diagnostics<\/li>\n<li>post-build issues and fixes<\/li>\n<\/ul>\n<h2>Project sEVen<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper-600x172.png\" alt=\"Cartoon Caterham Seven with EV purple bumper representing Project sEVen\" \/><\/figure>\n<p>Project sEVen is the electric conversion thread: taking an unloved 2012 Caterham Supersport SV and over-engineering my way through the myriad mechanical, electrical, control, and packaging problems that come with making a perfectly good ICE car electric.<\/p>\n<p>Start here:<\/p>\n<ul>\n<li><a href=\"\/index.php\/2022\/09\/30\/seven-index\/\">Putting the EV in sEVen &#8211; Index<\/a><\/li>\n<\/ul>\n<p>Useful themes:<\/p>\n<ul>\n<li>motor and gearbox packaging<\/li>\n<li>battery and high-voltage systems<\/li>\n<li>DC-DC converter work<\/li>\n<li>CAN bus and control systems<\/li>\n<li>3D scanning and CAD references<\/li>\n<\/ul>\n<h2>ECU Diagnostics And CAN Bus<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2019\/09\/ECU-OSI-Layers.png\" alt=\"ECU OSI layers diagram for the diagnostics and CAN bus series\" \/><\/figure>\n<p>The ECU diagnostics series explores the MBE ECU, OBD, CAN, ISO-TP, broadcast messages, decoding, and supporting tools. We get mostly to a conclusion, but in the end the project was more of a research project than a development project.<\/p>\n<p>Start here:<\/p>\n<ul>\n<li><a href=\"\/index.php\/2019\/08\/31\/ecu-diagnostics-part-1-introduction\/\">ECU Diagnostics &#8211; part 1 : Introduction<\/a><\/li>\n<\/ul>\n<p>Useful themes:<\/p>\n<ul>\n<li>CAN bus traffic<\/li>\n<li>MBE diagnostics<\/li>\n<li>OBD-II and ISO-TP<\/li>\n<li>Wireshark and GVRET tooling<\/li>\n<li>Python diagnostic tooling<\/li>\n<\/ul>\n<h2>3D Scanning And Model References<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2025\/09\/GearboxMountQuickie720p-600x338.gif\" alt=\"Animated gearbox mount scan used as a 3D model reference\" \/><\/figure>\n<p>Several posts contain scans, CAD references, and model-related notes. These are often useful because they are concrete: part names, geometry, mounting points, and working assumptions.<\/p>\n<p>Start with:<\/p>\n<ul>\n<li><a href=\"\/index.php\/2025\/09\/16\/caterham-5-6-speed-gearbox-mount-scan\/\">Caterham 5\/6 Speed Gearbox Mount Scan<\/a><\/li>\n<li><a href=\"\/index.php\/2025\/05\/29\/caterham-sv-nose-cone-scan\/\">Caterham SV Nose Cone Scan<\/a><\/li>\n<\/ul>\n<p>Useful themes:<\/p>\n<ul>\n<li>scan-to-CAD work<\/li>\n<li>Caterham geometry references<\/li>\n<li>gearbox and driveline packaging<\/li>\n<li>Project sEVen design references<\/li>\n<\/ul>\n<h2>Engine Cooling And Mechanical Notes<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2025\/03\/Simple-Engine-Cooling-Fanfold-600x338.jpg\" alt=\"Simple engine cooling fanfold diagram for Caterham Duratec cooling notes\" \/><\/figure>\n<p>Some posts are closer to engineering explainers than build-log entries. And example of that is the 3 year plus excursion into explaining the cooling of a 2.0L Ford Duratec engine as used in a Caterham.<\/p>\n<p>Start here:<\/p>\n<ul>\n<li><a href=\"\/index.php\/2025\/02\/02\/simple-engine-cooling-explained\/\">Simple Engine Cooling Explained<\/a><\/li>\n<li><a href=\"\/index.php\/2025\/03\/20\/simple-engine-cooling-low-flying\/\">SimplE Engine Cooling &#8211; Low Flying<\/a><\/li>\n<\/ul>\n<h2>Tooling And Side Quests<\/h2>\n<figure class=\"wp-block-image\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/04\/FCP-Full-600x338.jpeg\" alt=\"Final Cut Pro spectrogram screenshot from an agentic coding side quest\" \/><\/figure>\n<p>Purplemeanie also contains posts about coding, media tooling, animation, automation, and the occasional rabbit hole that became useful.<\/p>\n<p>Start here:<\/p>\n<ul>\n<li><a href=\"\/index.php\/2026\/04\/25\/spectrogram-an-agentic-coding-side-quest-into-final-cut-pro-audio-analysis\/\">Spectrogram: An Agentic Coding Side Quest Into Final Cut Pro Audio Analysis<\/a><\/li>\n<li><a href=\"\/index.php\/2024\/11\/29\/my-engine-animation-workflow\/\">My Engine Animation WorkFlow<\/a><\/li>\n<\/ul>\n<h2>Notes For Readers And Agents<\/h2>\n<p>This site is chronological and personal as well as technical. Older posts are often best understood in sequence. If you are trying to answer a technical question, prefer the project indexes and series introductions first, then use individual posts as supporting evidence.<\/p>\n<p>Travel and personal posts exist, but they are not the main engineering knowledge graph of the site.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A technical map of Purplemeanie engineering projects, including the Caterham build, Project sEVen, ECU diagnostics, 3D scanning, engine cooling, and tooling notes.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"footnotes":""},"class_list":["post-8080","page","type-page","status-publish","hentry"],"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P8yl38-26k","jetpack-related-posts":[{"id":6522,"url":"https:\/\/purplemeanie.co.uk\/index.php\/videos\/","url_meta":{"origin":8080,"position":0},"title":"Videos","author":"John Martin","date":"July 19, 2020","format":false,"excerpt":"Here's the videos I've uploaded to YouTube so far. You can find the channel here: Purplemeanie YouTube Channel Putting the EV in Seven - YouTube project kick-off video Putting the EV in Seven &#8211; Youtube Project Kick-off https:\/\/youtu.be\/gFBOlIhLBvo What to expect at a Novices Trackday \/\/ Taking a Caterham 420R\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/img.youtube.com\/vi\/gFBOlIhLBvo\/0.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":8095,"url":"https:\/\/purplemeanie.co.uk\/index.php\/build-images-may-2017\/","url_meta":{"origin":8080,"position":1},"title":"Build Images &#8211; May 2017","author":"John Martin","date":"September 30, 2022","format":false,"excerpt":"Caterham 420R Detailed Project Plan","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Detailed Gantt chart showing the Caterham 420R build task schedule.","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001-Detailed-150x150.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001-Detailed-150x150.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001-Detailed-150x150.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001-Detailed-150x150.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":28,"url":"https:\/\/purplemeanie.co.uk\/","url_meta":{"origin":8080,"position":2},"title":"Purplemeanie","author":"John Martin","date":"March 22, 2017","format":false,"excerpt":"Welcome to\u00a0the Purplemeanie blog of our Caterham journey. We hope you enjoy our trials and tribulations during and after the build. Please leave us a comment and tell us what you think. Where to Start The latest project from the Purplemeanie HQ is to have a go at converting a\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2020\/08\/Front-Page-Image-Cropped.jpeg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":6609,"url":"https:\/\/purplemeanie.co.uk\/index.php\/build-blog-index\/","url_meta":{"origin":8080,"position":3},"title":"Build Blog","author":"John Martin","date":"August 10, 2020","format":false,"excerpt":"Before we get into the index, some of you might want to watch the build time lapse video where I talk through the whole build: Build A Cateraham 420R in 30 Minutes If you're looking for a quick way of indexing the build blog... here it is: Pre-BuildIntroductionFirst Test DrivesPre-Build\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Engine hoist holding the engine beside the Caterham chassis during the build.","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/08\/IMG_1984-e1506632751828.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":8101,"url":"https:\/\/purplemeanie.co.uk\/index.php\/build-images-october-2017\/","url_meta":{"origin":8080,"position":4},"title":"Build Images &#8211; October 2017","author":"John Martin","date":"September 30, 2022","format":false,"excerpt":"Bottom diff mountings needed 2 (LHS) and 3 (RHS) washers Digital callipers used to work out how many spacing washers are needed. Measuring diff carrier to box section the old way Laser measuring distance from chassis box section to diff carrier Blanking\/skid plate in place. Material trimmed from skid plate.\u2026","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"Bottom differential mountings with spacing washers fitted on both sides.","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/09\/IMG_2604-150x150.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":8090,"url":"https:\/\/purplemeanie.co.uk\/index.php\/build-images-march-2017\/","url_meta":{"origin":8080,"position":5},"title":"Build Images &#8211; March 2017","author":"John Martin","date":"September 30, 2022","format":false,"excerpt":"","rel":"","context":"Similar post","block_context":{"text":"Similar post","link":""},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/03\/Caterham420r-400x300-for-website-150x150.png?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/pages\/8080","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/comments?post=8080"}],"version-history":[{"count":11,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/pages\/8080\/revisions"}],"predecessor-version":[{"id":11341,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/pages\/8080\/revisions\/11341"}],"wp:attachment":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/media?parent=8080"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}