Stock Ticker Machine

The problem with hardware is that bugs are much more of a pain in the arse. Unlike software you can't hide your hacks behind library boundaries

Because the paper can move left and right relative to the presser plate, it gets pinched. Which makes everything go wrong. This took a lot of fiddling to correct, but in the end the solution is quite simple:

The conformer makes sure that the paper can't move left or right, and surprisingly it works really well. It has lots of room for adjustment, which is a bit ugly, but means it actually works.

The other mess was the electronics. There is nothing ground breaking here, just two stepper controllers, a solid state relay and an ESP8266(wildly over powered). As we are dealing with 24v and lots of noise from the solenoids, I used a beefy SSR, so I didn't run the chance of accidentally shoving -32v through a USB line.

Its messy though

but with a bit of wobbling, it was tamed. Plus with this lid on, you can see it. Perfect is the enemy of good and all that.

Its not overly obvious in the hand drawn design, but the main point of the main plate is as follows:

• Host a printing wheel that has the letters on it
• contain a paper feeding mechanism
• Be solid enough to cope with the hitting and pressing of the paper

Because aluminium is expensive, I started prototyping in plywood, to make sure my assumptions were correct, and that it all fitted inside the jar

Even though I had the mechanical drawings of the motors, I hadn't allowed enough space to fit all the paper handling bits in.

The other mistake I had made was not accounting for the width of the metal plate that holds the solenoids. Having learnt from my mistakes, and making some tweaks, I finally milled the aluminium plate

You can see some scratches in the black gloss, note to self, always finish your aluminium properly.

Its starting to look really nice now.

Normally I'd not bother with a logo, but as I've been given a Illustrator license through work, and the explosion in cheap heritage style clip art, means that its easier than ever for me to make a logo. Not only that, with the workbee its trivial to get that logo engraved in brass.

When engraving its really really important to make sure that your workbed is parallel to the spindle *and* that you've clamped your workpiece properly. As the depth of cut is <0.25mm it makes all the difference. TLDR: make sure you've surfaced your spoilerboard.

When I was designing the logo, I realised that the stock base that comes with the HÄRLIGA isn’t tall enough to house the solenoids. So I need to mill a base extension:

This is useful because I now have a form to hammer the logo plate into.

Here is the finished logo in place.

Indian ink and acrylic gloss makes it much more believable:

Its time to cut the base. If you look at the hand drawn designs you can see that lots of attention is spent on making the base/stamping mechanism. I need to mill pockets to accept the solenoids and solenoid plate.

The great thing about having a workbee is that its trivial to cut wood with reasonable accuracy.

As good as the CNC machine is, it doesn't make up for user error, or my inability to measure.

The pressing foot is fitting really well

As I can't buy a stock ticker, I need to make one. The first step of course is designing what I want it to look like. I bought a bell jar from ikea years ago, and this seems like the best thing to design around

Roughly working out how the print mechanism will work

A more reasoned design with ideas about ink holding