Another year and another BarCamp London later and another project started. After a chat with John Rogers I ended with a set of Splitflap Chainlink Drivers in my possession from the swap shop and a firm suggestion that I should print myself a Splat Flip display.

A PCB - 'Splitflap Chain Link Driver v1.1'

Split Flap Displays

Before we go into any details I should probably introduce Split Flap displays for anyone who doesn’t know what they are. This kind of display are largely alphanumeric; , some additional symbols are also included1.

A commercial split flap clock

A commercial split flap clock - Amazon

These displays had a number of advantages over other display types when they will still in common use. Including the ability to have very high definition fonts, and the fact that they are not emissive meaning they don’t require power when not being changed.

The biggest critic of these displays (but also the reason they are so iconic) is the noise they make when changing values. This can be seen on the video below of a split flip display in a Paris train station.

The Plan

For now I am going with the design by David Kingman. I may need some changes however to enable me to print this on my Bambu A1 Mini which has a smaller build plate than he used. I have found a modified version of the frame that fits.

One change I am making right off the bat2 is that I don’t have multi filament support for my A1 Mini. So instead of the print in place flaps with font embedded i am planning to use blank flaps with vinyl cut lettering.

The Parts

The following items are on order from AliExpress:

I am hoping i have all the ’m’ screws in stock, and I still need find a supplier of the Hall effect sensors which are used to home the spools. I may use the Hall effect boards that John has designed.

Starting to Print

This brings us up to where I am now, with some test prints already started.

Part of the split flap mechanism

Part of the split flap mechanism

A split flap rotor with some flaps installed. All plastic parts are printed in black plastic. The object is being held in a hand.

A split flap rotor with some flaps installed

This has already brought up a few things… This project is going to take a LONG time to print on my little printer. The Bambu Smooth PIE plate along with enabling ironing in the slicer is required to get a nice surface finish on the split flaps. On the other hand the split flaps are VERY hard to remove from the smooth plate.

Follow Along

If you want to follow along if before I write the next part of this blog post then I am keeping John Rogers up to date on mastodon.

Mastodon avatar for @John@chaos.social@mastodon.social
John @John@chaos.social@mastodon.social

@Mexicals

Great to meet you. Let me know how you get on with the splitflaps.
I do have a few of the buddy boards I could send you, If you wanted!
I can also provide links to what I did if needed!

10:54 PM • November 23, 2024 (UTC)

  1. Because of the design there isn’t actually a limitation on what can be displayed on each “character”. The limit is the number of flaps in the “unit”, and each unit can have different flaps. This means that colour and symbols are possible. ↩︎

  2. Writing this I learnt that I have been saying write off the back instead of bat for the longest time… Thanks as ever to Pol for QAing my blog posts in his spare time. ↩︎