1921 Ner-A-Car Motorcycle Reborn With Epic Parts Remanufacture

Most of the rusty parts you need to make a motorcycle.
Most of the rusty parts you need to make a motorcycle.

Nobody ever dismantles a working motorcycle.

About ten years ago [Andy Pugh] took possession of a large box of rusty parts that formed most of what had once been a 1921 Ner-a-Car motorcycle. They languished for several years, until in 2014 he was spurred into action and returned to the bike. What followed was a two-year odyssey of rebuilding, restoration, and parts remanufacture, and since [Andy] is an engineer par excellence and an active member of the LinuxCNC community his blog posts on the subject should be a fascinating read for any hardware hacker with an interest in metalwork.

The Ner-a-Car. By Museumsfotografierer (Own work) [Public domain], via Wikimedia Commons
The Ner-a-Car. By Museumsfotografierer (Own work) [Public domain], via Wikimedia Commons
The Ner-a-Car represents one of those eccentric dead-ends in automotive history. Designed in 1918 by an American, [Carl Neracher], its name is a play on both its designer and its construction and it is unique in that its design is closer to the cars of the era than that of a motorcycle. It has a car-style chassis, an in-line engine, and it was the first motorcycle to be produced with hub-centre steering. The rider sits on it rather than astride it, feet-forward, and the car-style chassis gives it a very low centre of gravity. They were manufactured in slightly different versions in both the USA and the UK, and [Andy]’s machine is an early example from the British production line. Not many Ner-a-Cars have survived and parts availability is non-existent, so his work has also had the unusual effect of satisfying a significant portion of world demand for the parts-bin of an entire marque.

Spinning up a headlight shell
Spinning up a headlight shell

It’s usual for the first link in a Hackaday article to be to a page that encompasses the whole project. In this case when there is so much to see and the build is spread across twelve blog posts and nearly two years the link is to [Andy]’s first post in which he describes the project, sets to work on the chassis, and discovers the bent steering arm that probably caused the bike’s dismantling. He’s listed the posts in the column on the right-hand side of the blog, so you can follow his progress through the entire build. The work involved in remanufacturing the parts is to an extremely high standard, from machining press tools to reproduce 1920s footboard pressings through manufacturing authentic 1920s headlight switchgear and metal-spinning new aluminium headlight shells.

[Andy]’s most recent Ner-a-Car post details his trip to France on the completed bike, and tales of roadside repairs of a suddenly-not-working machine that should be familiar to any owner of a vintage internal combustion engine. But considering that the bike spent many decades as a pile of not much more than scrap metal the fact that it is now capable of a trip to France is nothing short of amazing.

This is the first rebuild of a vintage bike from a box of rusty parts we’ve featured here – indeed it could almost be a retrotechtacular piece in its detailed look at 1920s bike design. These pages have however seen many motorcycle related  hacks over the years. We particularly like this from-scratch engine build and this gas-turbine bike, but it is the emergency motorcycle build in the desert from a Citroën 2CV car that has us most impressed. Please, ride safe, and keep them coming!

Error Correction of 3D Printers

From the very first RepRaps to the newest and latest printers off the Makerbot assembly line, nearly every consumer 3D printer has one significant shortcoming: it cannot recover from missed steps, slipped belts, or overheating stepper drivers. Although these are fairly rare problems, it does happen and is purely a product of the closed open-loop control system used in 3D printer firmware.

[Chris Barr] has come up with a rather clever solution to this problem. He’s designed a system that will detect and correct problems with the mechanics of 3D printers. It’s technically not a closed-loop control system, but it does allow him to get the absolute position of a nozzle on the build plate, detects error states, and can automatically calculate the number of motor steps per millimeter. It’s also much simpler than other closed loop control systems we’ve seen in the past, requiring only a few bits and bobs attached to the axes and to the printer controller board.

[Chris]’ system uses a magnetic encoding strip, a single chip, and a little bit of support circuitry. It’s actually not that much different from the moving axis on a desktop inkjet printer. It’s not closed loop, though; the firmware hack is only a ‘basic error correction’ that moves the nozzle back to where it should be. Although this is somewhat of a kludge, it is much simpler than refactoring the entire printer firmware.

In the video below, [Chris] demonstrates his solution for error correcting the printer by jerking his axis around during a print. The nozzle miraculously returns to where it should be, producing a usable part.

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