{"id":11049,"date":"2025-11-30T18:48:14","date_gmt":"2025-11-30T18:48:14","guid":{"rendered":"https:\/\/purplemeanie.co.uk\/?p=11049"},"modified":"2026-05-27T21:35:17","modified_gmt":"2026-05-27T20:35:17","slug":"project-seven-pt7-qa-and-weekly-updates","status":"publish","type":"post","link":"https:\/\/purplemeanie.co.uk\/index.php\/2025\/11\/30\/project-seven-pt7-qa-and-weekly-updates\/","title":{"rendered":"Project sEven pt7 : Q&amp;A and Weekly Updates"},"content":{"rendered":"\n<p>Quick update video this week. I picked a few of the questions from the last YouTube video and give a quick update on what I&#8217;ve been up to this week.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<span class=\"embed-youtube\" style=\"text-align:center; display: block;\"><iframe loading=\"lazy\" class=\"youtube-player\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/kJteEJRCbA4?version=3&#038;rel=1&#038;showsearch=0&#038;showinfo=1&#038;iv_load_policy=1&#038;fs=1&#038;hl=en-US&#038;autohide=2&#038;wmode=transparent\" allowfullscreen=\"true\" style=\"border:0;\" sandbox=\"allow-scripts allow-same-origin allow-popups allow-presentation allow-popups-to-escape-sandbox\"><\/iframe><\/span>\n<\/div><\/figure>\n\n\n\n<p>Here&#8217;s the chapter list:<\/p>\n<ul>\n<li>00:26 &#8211; Quick Project Recap<\/li>\n<li>00:50 &#8211; Q&amp;A &#8211; Mission Statement<\/li>\n<li>01:16 &#8211; Is it Achievable<\/li>\n<li>01:37 &#8211; Is it Emotional<\/li>\n<li>02:22 &#8211; Is it Affordable<\/li>\n<li>02:57 &#8211; Vehicle Safety<\/li>\n<li>05:17 &#8211; Why are the Chargers on the High Side<\/li>\n<li>06:42 &#8211; Steering Column Knuckles<\/li>\n<li>07:20 &#8211; Attention to Detail<\/li>\n<li>07:52 &#8211; It\u2019s time for an Update<\/li>\n<li>08:05 &#8211; Schematics<\/li>\n<li>09:15 &#8211; Drive Shafts, Diff and Prop Extracted<\/li>\n<li>12:26 &#8211; Scanned and Modelled Prop-shaft<\/li>\n<li>13:31 &#8211; Prop-shaft 3D Model<\/li>\n<li>15:03 &#8211; Battery Terminal Caps<\/li>\n<li>16:02 &#8211; Gearbox is GA Complete<\/li>\n<\/ul>\n\n\n<h2>Video Chapters<\/h2>\n<ul>\n<li>[00:26] Quick Project Recap<\/li>\n<li>[00:50] Q&amp;A \u2013 Mission Statement<\/li>\n<li>[01:16] Is it Achievable<\/li>\n<li>[01:37] Is it Emotional<\/li>\n<li>[02:22] Is it Affordable<\/li>\n<li>[02:57] Vehicle Safety<\/li>\n<li>[05:17] Why are the Chargers on the High Side<\/li>\n<li>[06:42] Steering Column Knuckles<\/li>\n<li>[07:20] Attention to Detail<\/li>\n<li>[07:52] It\u2019s time for an Update<\/li>\n<li>[08:05] Schematics<\/li>\n<li>[09:15] Drive Shafts, Diff and Prop Extracted<\/li>\n<li>[12:26] Scanned and Modelled Prop-shaft<\/li>\n<li>[13:31] Prop-shaft 3D Model<\/li>\n<li>[15:03] Battery Terminal Caps<\/li>\n<li>[16:02] Gearbox is GA Complete<\/li>\n<\/ul>\n<h2>Transcript<\/h2>\n<p>[00:00] Hello everyone, I&#8217;m John Martin and welcome to another Purplemeanie Project 7 update video. In this video. I&#8217;m going to do a couple of things. I&#8217;m going to get to some Q and A of some of the questions and comments that were brought up in the last video. And I&#8217;m also going to give you a bit of an update on where I am and what I&#8217;ve done this week. I can&#8217;t promise I&#8217;m going to get one of these videos out every week, but for the moment, it seemed like a good time to get another video out to you.<\/p>\n<h3>Quick Project Recap<\/h3>\n<p>[00:27] In this project, we&#8217;re taking an unloved 2012 K-Trum 7 SV, and converting it to B a shiny electric vehicle. We&#8217;re taking out. all the oily stuff, and replacing it with an electric drivetrain and some batteries. And I&#8217;d recommend this video up here if you&#8217;re interested in an overview of the project.<\/p>\n<h3>Q&amp;A \u2013 Mission Statement<\/h3>\n<p>[00:51] So let&#8217;s get going on the Q and A. The first question that came up was one of the broadest questions you can get for the project, and I thought it was worth probably having another look at that at this moment in time. And that&#8217;s about the mission statement. What&#8217;s this project all about? Well, there are three main things, I think, that define this project. Is it achievable? Is it emotional? And is it affordable?<\/p>\n<h3>Is it Achievable<\/h3>\n<p>[01:18] In terms of, is it achievable? Well, can we take all of this power that we&#8217;re going to need and squeeze it into something the size of a seven? Can we deliver? On the same sort of dynamics that you get in a. 420 r with an electric drivetrain.<\/p>\n<h3>Is it Emotional<\/h3>\n<p>[01:39] The second aspect of this mission statement is emotional, and that probably needs a little bit of explaining. So, driving a case room is a fairly exhilarating&#8230; even if you&#8217;re just pottering around town. The wind in your hair, the sound of the engine, swapping the cogs, these are all very important parts of the driving a Caterham experience. Can I achieve that in an electric 7? We&#8217;re getting rid of the cog swapping and we&#8217;re getting rid of a lot of the noise. But we&#8217;re going to be replacing it with that point and shoot electric car experience.<\/p>\n<p>[02:11] Driving around in a. Does that replace a lot of that feeling that you get? Does it replace the emotional element of driving around in a cage from 7? We&#8217;ll have to see.<\/p>\n<h3>Is it Affordable<\/h3>\n<p>[02:24] The third element of this is affordable, and that may seem a bit of a weird statement to make, having seen how much I&#8217;m putting into this project. But the idea is to develop a prototype, and then probably costs reduce it, to see whether we can cost engineer it down to something that is, perhaps have few 10s of 1000s of pounds in order to create a catering conversion. I know that&#8217;s not cheap in a lot of people&#8217;s views of what an electric car conversion is.<\/p>\n<p>[02:51] But I think that&#8217;s an achievable goal for this project. So is it affordable?<\/p>\n<h3>Vehicle Safety<\/h3>\n<p>[03:00] The 2nd question that came up that I thought was worth having a bit of a look at was the safety related issues around the project. I showed the block diagram in the last video about how this was all going to be put together electrically. And that wasn&#8217;t meant to be taken too literally. There&#8217;s a whole bunch of stuff that isn&#8217;t included on that diagram. But one of the key things is the safety relating side of this, and that&#8217;s often delivered in a number of different ways.<\/p>\n<p>[03:22] The 1st one is what is known as a high voltage interlock loop. And that&#8217;s a loop of wire that runs through all of the components on the block diagram, and if that wire is broken, then the vehicle control unit. shut down the hole of the car. You can&#8217;t just disconnect the high voltage power on one of these systems. You have to bring down the system in an organized and methodical way so that you protect all the components in the drivetrain. The 2nd part of the safety features&#8230;<\/p>\n<p>[03:49] going to be the cutoff switches. I&#8217;m going to be mounting cutoff switches both on the dashboard and behind my elbow, so that if I&#8217;m in a situation where the car isn&#8217;t doing what I want, I can easily reach for a cutoff switch, either in front of me or behind me, and that will shut down the electronics in that organized manner that we talked about before, and bring me to a stop. The third safety part is the crash detection. On a regular caterum, an inertia switch, that if the car was to tilt, above a certain angle.<\/p>\n<p>[04:20] The inertia switch cuts off the fuel pump. I&#8217;m going to have the same inertia, which, in this project, but it&#8217;s going to be connected to the vehicle control unit, and then on to the other components within the system, so that it knows if there&#8217;s been some incident where either there&#8217;s a high G load in a lateral direction, or if the car was to tilt at a certain angle, then the tilt switch will deactivate the rest of the car and bring us to a hole.<\/p>\n<p>[04:46] There&#8217;s also a fourth part of this safety, which is around about the static safety of the car. What happens when you&#8217;re working on the car, or if there&#8217;s a problem by the side of the road and somebody needs to de-energize the car? Well, that&#8217;s where the master service disconnects, which is come in, and I&#8217;ve already got some of those in the block diagram. And the idea is that it&#8217;s in a very prominent place so that when someone pulls the bonnet off, it&#8217;s very obvious where the master service disconnect is, they pull the plug.<\/p>\n<p>[05:14] And that de-energizes the whole system.<\/p>\n<h3>Why are the Chargers on the High Side<\/h3>\n<p>[05:19] The next question is a little more technical. And I got asked, why did I put the charging circuitry on the high side of the traction DC-DC converter? And the main reason for that comes down to flexibility, really. With the low voltage side of the traction DC-DC converter being 6 modules at around about&#8230; 260 something volts. I wanted some flexibility around that, and be able to take some modules off, reduce the weight of the car, maybe add one or 2 modules.<\/p>\n<p>[05:51] To increase the range. But that would mean all the electronics on the low side of the DC to DC converter might have to change. Some of the software might have to get rewritten, but certainly some of the parameters would have to change. The other factor is that I wanted to add DC fast charging to the car at some point. Now, the DC fast charges on the roadside do have variable voltage that they can cope with. They can charge different voltages and different currents.<\/p>\n<p>[06:18] But a lot of the systems don&#8217;t cope very well when you get the voltage really low and they don&#8217;t cope so well when you take the voltage really high. And the easiest way of doing that, in my mind, was to, Put the AC charging and the DC charging. the high side of the traction DC to DC converter. We&#8217;ll have to see if that&#8217;s a good idea or not. But in my mind, that was the best way to go.<\/p>\n<h3>Steering Column Knuckles<\/h3>\n<p>[06:44] Another good question I got was, in order to give myself more room in the engine bay, why didn&#8217;t I think about moving the routing of the steering column that runs diagonally through the engine bay, could I not move that around with a couple of knuckle joints or something to give myself more space in the engine bay? For more battery modules. Well, I certainly thought about that. And I&#8217;ve got a friend who&#8217;s got exactly that sort of arrangement on his car. But that was another engineering step that I just didn&#8217;t want to go to at the moment.<\/p>\n<p>[07:14] Certainly considered it at one point. And that&#8217;s a fallback plan I can come back to if I really need it.<\/p>\n<h3>Attention to Detail<\/h3>\n<p>[07:22] The final thing I wanted to bring up in this Q and A session was the consistent comment I got about attention to detail and how people are enjoying the amount of work and effort I&#8217;m putting into the project. That&#8217;s very humbling from my point of view. I&#8217;m really pleased that people are getting some enjoyment out of this, and hopefully people are learning a little bit about my journey. It may not be the way to go and do an electric car conversion, but they&#8217;re learning about my journey and the decision processes I&#8217;m going through in order to get to where I want to be.<\/p>\n<h3>It\u2019s time for an Update<\/h3>\n<p>[07:54] Okay, so we&#8217;ve had a look at some of the questions and comments that have come in on the last video. It&#8217;s only been a week since I put that video out. But let&#8217;s have a look at what I&#8217;ve been doing this week and give you a flavor of where we&#8217;re at.<\/p>\n<h3>Schematics<\/h3>\n<p>[08:08] The 1st thing I&#8217;ve been up to is going back and having a look at the schematics. Now, I&#8217;m creating a bunch of schematics for this project. And it isn&#8217;t individual schematics to create printed circuit boards or anything like that. It&#8217;s more of a schematic to create the wiring looms and the interconnections between all of the components in the design. And over Infusion 360, we can see, I&#8217;ve got a whole bunch of schematic, Set up at the moment. And this week has really been about creating the symbols that go into the schematics.<\/p>\n<p>[08:44] I had a big schematic that I was working on previously. But I&#8217;ve decided to split this up into multiple. And that&#8217;ll really help me tie down where everything gets connected. What connections on the vehicle control unit can be used? What connections on the power delivery module can be used, how I&#8217;m going to drive all the pumps? Interconnect. contactors in the various places. It also defines what components are going to sit on what canvases. So, that&#8217;s where I am with schematics. Fairly big chunk of this, the early part of this week.<\/p>\n<h3>Drive Shafts, Diff and Prop Extracted<\/h3>\n<p>[09:18] The next thing I got to this week was actually to get&#8230; The prop shaft out of the project car. Now, that sounds like a fairly simple thing to do, but on a case room, there&#8217;s a bit of a process to that. And so in order to get the prop shaft out. It won&#8217;t come out with the front of the car. I&#8217;ve got the engine room gearbox removed. You think it might come out of the front, but that doesn&#8217;t, it doesn&#8217;t happen.<\/p>\n<p>[09:37] It&#8217;s too tight down there. So it has to come out the back. And in order to get it out of the back, you have to take off the driveshafts, take out the differential, and then that gives you enough space to be able to pull the prop shaft out of the transmission tunnel and remove it. And just a reminder, I need the prop shaft out so I can test the fit. For it. Into the new gearbox, we&#8217;re a bit worried about the spline measurements in the gearbox.<\/p>\n<p>[10:03] We can&#8217;t find the definitive explanation of what the spline parameters are. And so, I&#8217;m going to need to do. Some test cuts of that spline. And also, I want to be able to get a 3D model of the prop shaft so I can put that into modern models and make sure that I can fit the correct prop shaft in. I&#8217;m going to need to get the prop shaft retubed. So that means taking the end caps off, and Bailey Morris will then put a new tube on into those end caps and create me a prop shaft of the correct length.<\/p>\n<p>[10:35] So I need to be able to get a model, put it into my bigger space planning model and then figure out how all of that is going to fit properly. So I need the prop shaft out, and I&#8217;ll give you a quick rundown on what goes into all of that. Here I am at the lockup, in my romper soup. First thing to do is to drop the A frame, so that gives me enough room to be able to pull the differential out later.<\/p>\n<p>[10:58] Next, we have to drain out all of the transmission fluid from the differential, and I use a pump to be able to do that, pull out some fluid. very slow process, especially in the cold that we&#8217;ve got at the moment, into the tank. And when it starts to slip, you know you&#8217;ve got air you&#8217;re pulling through. The fluid looks a bit black, but in my experience, that&#8217;s fairly typical for a K from differential. Nothing to worry about there. Next, we pull out the 4 bolts that hold the ears onto the Dion tube, and then we can slip one driveshaft out.<\/p>\n<p>[11:37] And then the 2nd one comes out. Oh, there we go. Next, we have to drop the differential. And that&#8217;s held into the chassis in a carrier. You undo the two bottom bolts on the carrier, and then one very long bolt on the top that gets knocked through. That releases the differential. I thought I was gonna drop it at the bottom, but in the end, I managed to pull it up through the top.<\/p>\n<p>[12:08] And last but not least, I can lie under the car and feed the prop shaft out of the rear of the vehicle. Now we have it, two drive shafts, differential, and the prop shaft. So that was about a 3.5 hour project for me, space over 2 days. And that gets me ready to be able to scan the prop shaft and then 3D model it.<\/p>\n<h3>Scanned and Modelled Prop-shaft<\/h3>\n<p>[12:29] Okay, so now we&#8217;ve got the prop shaft out of the car. Time to do a bit of scanning, and then we can pull it back into the computer. Here, we&#8217;ve got the model scanned in the Shining 3D software. Just need to mesh that.<\/p>\n<p>[12:49] from the model. After it&#8217;s aligned, we can export the scan. And pull that into fusion 360. Here we are in Fusion 360 again. This is the scan of the prop shaft. The differential plate here, sits here, and then the spline on this end, connects into the gearbox. Uh, I&#8217;ve got a reasonably good scanner. Of this. It would have been nice perhaps to have got into some of these knuckles in here, the crosses in here a bit more. But&#8230; All you really need is to be able to identify all of the main diameters of things.<\/p>\n<p>[13:25] Uh, positions on some of the holes. And&#8230; From that, I can model the whole thing up.<\/p>\n<h3>Prop-shaft 3D Model<\/h3>\n<p>[13:34] And here we have what I&#8217;ve modeled. I haven&#8217;t completed all of the model, but I&#8217;ve done what I need in order to be able to figure out, uh, the relevant bits and pieces that I need for my project. But I have managed to put all of the joints into this so that if I grab hold of it and move it around. It articulates the right way. And I also managed to create a parametric version. So this is the length of this for the SV chassis, the 580 millimeters between the center of the this universal joint and the center of this universal joint.<\/p>\n<p>[14:14] That&#8217;s the measurement that Bailey Morris used to define their prop shafts. But I&#8217;ve also created different versions so that I can change the. Uh, size of the prop shaft. I think it&#8217;s going to need to be 670 millimeters between these 2 universal joints. in my EV project. So that&#8217;s my simple parametric model of the catering prop shaft. Took me 2 or 3 hours to scan the project using my. Shining 3D HX. That got me about 8000000 polygons. Uh, remesh that down to about 800,000 and that&#8217;s what I used to create this model.<\/p>\n<p>[14:54] Then it took me an evening, sat in front of the telly to be able to model up. The parametric version. So, there you go. That was another project for this week.<\/p>\n<h3>Battery Terminal Caps<\/h3>\n<p>[15:05] Another little project I did that was actually a couple of weeks ago, but I thought I&#8217;d just pick up on it here, is that. With these high voltage modules, I&#8217;ve got, uh, sitting around. I didn&#8217;t really like the idea of the battery terminals. Exposed as the. Sat behind me down here. So I modeled up some terminal caps, fairly simple little terminal caps with a plus and a minus on them. Throw them to the bamboo X1 carbon. And then use the standard terminal bolts to bolt them onto the caps just stops me being able to&#8230;<\/p>\n<p>[15:39] I have a problem if I drop a screwdriver or brush past it with something accidentally. It&#8217;s not really going to cause a big problem in the state they&#8217;re in at the moment. But as I move through the project and I start wiring things up a bit more, then it would be nice to have some caps that I can just put onto the battery terminals and know that there&#8217;s some degree of safety involved in handling them and moving them around.<\/p>\n<h3>Gearbox is GA Complete<\/h3>\n<p>[16:04] Okay, so now for the final update of the week, and it&#8217;s a big one. We now have. The general assembly of the gearbox completed. There&#8217;s still a few cosmetic issues to get ironed out like the calling fins on the outside. But essentially, the design is complete, and we are going to go ahead with what we&#8217;ve got now. So over here in fusion, we&#8217;ve got the completed design, you&#8217;ll remember that on the left-hand side here is the input from the motor, and on the right-hand side, we have the output spline to the prop shaft.<\/p>\n<p>[16:39] I will do a bigger update video at some point on the internals of the gearbox and a bit more going to a bit more detail, but for the moment, let&#8217;s just have a quick look at what is involved here. So here&#8217;s the sectional analysis. I&#8217;ll just run over things fairly quickly. Uh, you&#8217;ve got the&#8230; Input shaft here, which is the sun in the planetary system. You&#8217;ve got the output shaft going to the prop shaft, and then in here, we&#8217;ve got the planets in here and a carrier.<\/p>\n<p>[17:15] A number of things that have been worked on recently and finalized this cylindrical roller bearing arrangement here, which is preloaded, and a four point contact bearing here, that is handling the axial loads on the sun. One of the issues you&#8217;ve got in. Helical. Planetary system is the axual loads front to back, generated by the helix angle. So that&#8217;s being catered for by mostly by this poor contact roller bearing and the radio loads being handled by the cylindrical roller bearing. Then we&#8217;ve got 2 fairly standard bearings sat here on the output shaft, 2 bearings to steady the shaft so that it can&#8217;t wobble.<\/p>\n<p>[18:01] And then in here, there are roller bearings, 2 roller bearings on each pin. So this green thing is a pin that sits through the center of the planet and then these&#8230; Roller bearings are what the planets run on. So that&#8217;s a fairly quick look at the gearbox. We are GA complete. Hurrah.<\/p>\n<p>[18:25] And while we&#8217;re talking about the gearbox, I just wanted to bring up something that I probably forgot in the last video, and that&#8217;s to say about my 3D print of the gearbox. This is from a design a few weeks ago, so it&#8217;s not quite the same as what we&#8217;re completed on now. But over here, I have. The gearbox. And I did a sectional view of it. So you can see that&#8217;s inside. This one, I have done 3D printed bearings in here.<\/p>\n<p>[18:56] Hopefully, you can see that. 3D printed bearings, just to keep the cost down, and as we were changing things, it was so much easier, just to 3D print them rather than just go and buy a whole load of bearings. This thing works. I like to print things out in different colors. That way, when I&#8217;m talking to somebody about it, and we get a bit confused about what we&#8217;re talking about, I can say, the red thing, or the yellow thing, or these purple bearings.<\/p>\n<p>[19:23] That makes life a little bit easier when we&#8217;re having&#8230; conversations about what&#8217;s going on. Fantastic that you can take a step file, and you can dump out a 3D model of it. So that was a quick Q and A and an update on what I&#8217;ve been up to this week. We&#8217;ve had a lot of progress this week. That&#8217;s not uncommon for my weeks. It&#8217;s just we haven&#8217;t caught up on this for the whole 2 years that we missed, but this is not uncommon for the amount of work I&#8217;ve put into a week.<\/p>\n<p>[19:54] And the next video will probably be another update. Not quite sure when that&#8217;ll be. But until then, I hope you enjoyed this video. So I&#8217;ll say stay safe and have you blatting.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Project sEVen Q&#038;A and weekly update video covering the mission, project feasibility, recent progress, and viewer questions around the Caterham EV conversion.<\/p>\n","protected":false},"author":1,"featured_media":11050,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"They're coming quick and fast now... this time a quick response to some questions and this week's updates. We're GA complete on the Gearbox... yay!","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[51,38,26],"tags":[66,57,64,30],"class_list":["post-11049","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-caterham-blog","category-electric-vehicles","category-youtube","tag-caterham","tag-electric-vehicles","tag-project-seven","tag-youtube"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/purplemeanie.co.uk\/wp-content\/uploads\/2025\/11\/PTEVIS7-QA-Update-003-scaled.jpg","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8yl38-2Sd","jetpack-related-posts":[{"id":8125,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2022\/09\/30\/seven-index\/","url_meta":{"origin":11049,"position":0},"title":"Putting the EV in sEVen &#8211; Index","author":"John Martin","date":"September 30, 2022","format":false,"excerpt":"Project sEVen is the electric conversion thread for the Caterham, covering mechanical packaging, EV power electronics, CAN bus diagnostics, 3D scanning, CAD references, and systems integration.","rel":"","context":"In &quot;Caterham Blog&quot;","block_context":{"text":"Caterham Blog","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2022\/09\/Cartoon-Seven-Vector-with-EV-Purple-Bumper.png?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":11261,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2026\/02\/22\/project-seven-jan26-update-short\/","url_meta":{"origin":11049,"position":1},"title":"project sEVen Jan26 Update Short","author":"John Martin","date":"February 22, 2026","format":false,"excerpt":"Quick update video. Just getting the test bench set up. Lots is going to change in the next few weeks. https:\/\/youtube.com\/shorts\/7cyrt5BPVSQ","rel":"","context":"In &quot;Caterham Blog&quot;","block_context":{"text":"Caterham Blog","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/IMG_1882-Annotated-scaled.png?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":11251,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2026\/02\/22\/project-seven-update-feb26-short\/","url_meta":{"origin":11049,"position":2},"title":"Project sEVen Update Feb26 Short","author":"John Martin","date":"February 22, 2026","format":false,"excerpt":"Brusa BDC668 traction DC2DC converter working on the bench. A quick update on progress with my Project sEVen test bench. As I build up the system to eventually get my motor spinning on the bench, today I get as far as running up the Brusa BDC668 to do a DC\u2026","rel":"","context":"In &quot;Caterham Blog&quot;","block_context":{"text":"Caterham Blog","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-22-at-12.52.51.jpeg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":296,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2017\/05\/07\/pre-build-update-5-a-project-planned\/","url_meta":{"origin":11049,"position":3},"title":"Pre-build Update #5 \u2013 A Project Planned","author":"John Martin","date":"May 7, 2017","format":false,"excerpt":"Pre-build update covering project planning, scheduling, and preparation for the Caterham 420R kit build.","rel":"","context":"In &quot;Caterham 420R Build&quot;","block_context":{"text":"Caterham 420R Build","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/caterham-420r-build\/"},"img":{"alt_text":"High-level Gantt chart for the Caterham 420R build project.","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001.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.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/05\/Caterham-420R-Project-Plan-001.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.png?resize=700%2C400&ssl=1 2x"},"classes":[]},{"id":8341,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2023\/05\/10\/putting-the-ev-in-seven-youtube-project-kick-off\/","url_meta":{"origin":11049,"position":4},"title":"Putting the EV in sEVen &#8211; Youtube Project Kick-off","author":"John Martin","date":"May 10, 2023","format":false,"excerpt":"Project sEVen kickoff video introducing the Caterham electric conversion, the project goals, and why the video series exists alongside the written build notes.","rel":"","context":"In &quot;Caterham Blog&quot;","block_context":{"text":"Caterham Blog","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2023\/05\/PTEVIS1-001-10-scaled.jpg?resize=1400%2C800&ssl=1 4x"},"classes":[]},{"id":286,"url":"https:\/\/purplemeanie.co.uk\/index.php\/2017\/04\/30\/pre-build-update-4-the-colour-is-lotus-aubergine\/","url_meta":{"origin":11049,"position":5},"title":"Pre-build Update #4 \u2013 The Colour is Lotus Aubergine","author":"John Martin","date":"April 30, 2017","format":false,"excerpt":"Pre-build update confirming Lotus Aubergine as the Caterham 420R colour choice and recording the specification direction.","rel":"","context":"In &quot;Caterham 420R Build&quot;","block_context":{"text":"Caterham 420R Build","link":"https:\/\/purplemeanie.co.uk\/index.php\/category\/caterham-blog\/caterham-420r-build\/"},"img":{"alt_text":"Rear line drawing of a Caterham Seven with roll bar and rear wings.","src":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=525%2C300&ssl=1 1.5x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=700%2C400&ssl=1 2x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=1050%2C600&ssl=1 3x, https:\/\/i0.wp.com\/purplemeanie.co.uk\/wp-content\/uploads\/2017\/04\/R500-Sketch-Rear.png?resize=1400%2C800&ssl=1 4x"},"classes":[]}],"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/posts\/11049","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/types\/post"}],"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=11049"}],"version-history":[{"count":3,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/posts\/11049\/revisions"}],"predecessor-version":[{"id":11366,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/posts\/11049\/revisions\/11366"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/media\/11050"}],"wp:attachment":[{"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/media?parent=11049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/categories?post=11049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/purplemeanie.co.uk\/index.php\/wp-json\/wp\/v2\/tags?post=11049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}