EEVblog 1419 - Sinclair C5 Restoration - Part 2

RIP Sir Clive Sinclair.
Dave finally gets around to starting to take apart and restore the classic Sinclair C5 electric vehicle.

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[SeanBZA]

Body likely would be nice if you got it all cleaned off with some sugar soap and water, followed by a polish with some automotive buffing compound, and then a final going over with paste wax. Will give it a much better finish, without taking too much off other than the oxidised paint top layer. The wax will then protect it further. Anything more you will need a bumper repair shop to strip it down, do a proper primer coat, then a few topcoats of a flexible paint, and then a final clear coat over it all.

Black inner and plastic parts simplest will be to wash it as well, then get a bottle of pure silicone tyre and bumper polish, and apply liberally, though note it will make them hydrophobic, and incredibly slippery, and for a while, till it soaks in, a dust magnet. The silicone can be wiped over the entire vehicle as well, it will do a good job of preserving it, though not a good idea if you ever intend to repaint it, as it will be hard to remove, and will cause the paint to fish eye all over.

Chassis needs to be stripped out, and then reinforced with a bit more steel where the original spot welds have cracked, preferably using a rib that fills the entire length, and which is MIG welded down all the way. Then cleaned off, rust removed with rust converter inside and out, and the inside liberally sprayed with linseed oil, after you have sprayed the outside with a coat of grey primer. The linseed oil will fill in all those tiny crevices, and polymerise, so the metal will not rust further.

Very likely the gauge unit does not work any more, those Ferranti ULA's were not exactly known for being a reliable part. Incidentally I still have a Sinclair amplifier kit, complete in bag, with the original no name branded reject Mullard transistors that were used in the kits, as they were available for scrap metal prices, and Sinclair would simply test each one, and those which had the faintest bit of life, some gain, and minimal leakage at 12V were then used in the kits. Might not work at 30V, but will not fail immediately with 12V, and anything with a gain over 2 could be used. If I ever build it it would need all new capacitors, doubt the originals are any more useful other than as a space filler on the board.

[akhurash]

Would love to see this thing restored, especially with modern electronics. Hope you continue the series.

[stevehead]

I have a vague memory of Sinclair C5s being used as advertising hoardings, somewhere near Turnpike lane (London UK). I built a Sinclair scientific from a kit and it sort of worked, contact bounce was a problem, I think the most I got was 4 4s from one key depression. If you squeezed it but slightly during a calculation, the batteries would lose contact and you would lose the lot, not the most reliable device. Reverse polish notation, there's one for you, forgotten how to do do it now. Before he was a Sir, Clive Sinclair released a series of booklets mostly of transistor radio circuits, I'm sure I built a few. I recall him waxing lyrical about the marvellous OC169 transistor, no doubt by now, tin whiskers will have seen most of them off. Thank you, Sir Clive for your enthusiasm, ingenuity and inspiration to others.

[WacKEDmaN]

nice to see the C5 getting some love!...
RIP Clive...

[Alex-jeod]

* 9:59 - Remove that rust. Wire wheel on a drill. Then toss some self-etch primer on it.
* 11:01 - Chain needs some lube badly.
* 11:17 - that frame looks split. Needs tig welded back together before you start taking it out
* 13:18 - wheel support thing is toast.. no repairing that. Trace it on paper to get the dimensions before it gets more broken. Use some calipers and measure shape / depth, etc. Give to a local machinist to make up a new one.
* 13:31 - Those plastic belt gears look really brittle...
* 14:22 - A great time to use an impact wrench to knock those bolts loose without holding stuff


It looks like a lot of work. You'll need a bit of tig welding, some paint + grinding, and some custom fabricated parts. I'm sure a lot of stuff was plastic to save weight, but plastic doesn't age well in critical pieces.

Replace anything in the drive train with damaged plastic with metal, and convert to a chunky Li-Ion / LifePo4 for the batteries. The denser energy will make up for the weight gain.

[vincei]

Oh no! Clive passed away! RIP. The ZX81 was what got me into this field that I'm plugging away at all these years later. I assembled the ZX-81 kit and will never forget how proud I was as a young teen in Africa watching this thing boot for the first time with that flashing cursor. Thanks I guess for the sad news, Dave.

[michaelhall]

At 6:57, you can see the "spare" tire is Sinclair branded, so it's probably original, and the BMX-type tires that are on it are aftermarket.

[electronash]

RIP, Sir Clive Sinclair.


A true visionary of his time.

His ideas and business knowhow helped kickstart the computer industry in the UK and elsewhere.

He recognized that the price-to-entry for small home computers was quite high at the time, and knew he could do it more cheaply.

The £100 ZX Speccy was very popular here as a result, and many software devs owe their careers to that little machine.

Some big names from the likes of Sony, Nintendo, Microsoft, Rare got their start programming simple games on the Speccy in their younger years.

I think it's time to watch "Micro Men" (2009) again. One of the best dramas the BBC ever made, IMO.

Thanks for all the great memories, Sir Clive.

[SantaClaw]

The frame is cracked, where you asked if "is this due to rust" No - The welds have split, and it requires a few minutes with a welder to fix.

[bsvenss]

Thank you for many fun hours and days Sir Clive. RIP. I had the pleasure of owning and building some of your products,

- Sinclair Micromatic pocket radio kit (1967 - 1971)
- Sinclair "Black Watch" watch kit (1975)
- Sinclair Cambridge type 3, self-build calculator kit (1975)
- Sinclair ZX81 kit (1981)

My dream computer in 1984 was the Sinclair QL (Quantum Leap), but unfortunately, I could never afford to buy one.

[GeorgeWMays]

Absolutely you should continue the restoration. You may as well video the disassembly so that you can look back and see how things came apart. It would be fascinating to me to see how you sort out the electrics. Thanks for the video. Appreciated.

[AKsevenFOUR]

RIP Sir Clive. What an industry titan!

[Equiluxe]

My first digital multimeter was a Sinclair, It did not last long as it blew up, I took it apart and found that the case was the same as the calculator with a sticky lable covering the spare button holes. I met Clive Sinclair briefly in the 1970's, I was living in Cambridge at the time and a Sinclair amplifier that I had purchased via mail order failed soon after I turned it on so I took it back to his shop in Cambridge and Clive came out of his office looked at the unit briefly threw it in the bin and handed me another off the shelf saying "here you are" and turned and walked back into his office. The motor on those C5s was made by Hover and the frame is the same as the washing machines at the time, replace the motor with an AC washing machine motor and drive from a VFD. Looks like someone cobbled a speed control switch from a drill into it.

[JamesBakerOhio]

My first computer was a Timex Sinclair 1000 with a 32k memory addon, so many fond memories of coding simple BASIC programs and saving them to cassette tape with csave and cload. Wow those were the days. RIP Mr. Sinclair and thanks for the opportunities your frugal engineering afforded me.

[objection_your_honor]

The world lost another pioneer.
RIP Sir. You did good. I loved assembling my ZX81 kit back in 1981.

[ThePobolycwm]

the sinclair c5 always makes me nurse a semi so 3 physical thumbs up here and an electronic one on screen. my friends parents both assembled parts for these at Hoovers washing machine plant in Merthyr

[tenmillionvolts]

Good on ya Dave! Big thumbs up for the restoration. Sir Clive would be proud of you. I'll bet he's zooming around in his C5 in the clouds right now

[TradieTrev]

Must be one of the first times I've seen Dave's hands dirty working on something! Normally the only time is from the canyon climbs or mud runs lol

[mycosys]

The C5 was so far ahead of its time, can you imagine this thing with fibre reinforced plastics, AC motors & regen, LiFePO4 batteries, aluminium alloys, bike suspension thats now commonplace. It already looks like the inside of a Tesla. Sinclair had so much difficulty making the C5 a reality with 70s tech (and had to make a lot of compromises), hopefully someday soon someone can make his vision more of a practical reality, Vale Sir Clive, and Thank you.

[Knight]

Please do continue with the restoration, I'd love to see this come back to life. Maybe a Mr Fusion in the back & a few blue EL wires down the sides - but where would the flux capacitor go????