The Mk IV Teaching Station – Ignition Training LLC

Back in 2021 I wrote about the Mk III teaching station. It has worked brilliantly, but I have made some improvements.

Behold the Mk IV!

If you compare it to the Mk III, you will find that there have been no drastic changes but several improvements.

Before discussing the improvements, however, I think it’s probably worth explaining why the teaching station is important: it hides technology. “Yeah, right”, I predict you’re thinking. But it’s not about hiding the technology from me. It’s about hiding it from attendees. There’s no fumbling when I want to swap views from screen capture to diagram camera. If I want to have slides up and overlay a terminal session, I can. Zoom has got better since the earlier teaching stations. Still, it doesn’t offer the ability to mix video and audio feeds like OBS. Using just Zoom can lead to a stilted experience, turning even the most technically savvy presenter into someone who looks like they have trouble using the TV remote.

The Mk IV looks a lot nicer than the Mk III, but there are more meaningful reasons for the improvements, which I’ll discuss in the following sections.

1. Changes to the Desk
2. Monitors
3. Teleprompter
4. Reliability
5. Keyboard
6. 3D Printing
7. Background Screen
8. Things Retired

Changes to the Desk

For the Mk III, I used a small desk from Bush Business Furniture and added a custom-made sit/stand riser. Both have worked well, and I had deliberately wanted a tight workspace. More space would have been a better idea, but I wasn’t ready to make a desk at the time. I did so this summer.

The sit/stand riser from the Mk III was reused, but the shelf was lengthened and strengthened because the new monitors were larger.

Monitors

1. The ‘control’ monitor. This has OBS, Zoom, and other necessary control applications running. The screen is never shared in its entirety. In the Mk III, it was 1920x1080 but is now physically larger and 2560x1440.
2. The ‘output’ monitor. This shows the virtual camera output of OBS, and can also be captured by video conferencing software. This 1920x1080 monitor is physically small and was repurposed from some of the small monitors of the Mk III. It’s in a 3D-printed enclosure. A problem with the Mk III was spares - if one of the monitors failed, there was no backup. Now, this monitor has a backup on a nearby shelf, and can be clipped to the teleprompter in seconds.
3. The teleprompter. The monitor is mounted horizontally, and the image we see is a reflection. Hence, it is dimmer than the other images. The teleprompter was rebuilt to be much larger than the old teleprompter and now has a portable 15.6" screen. It is the same size as screen 4, and a spare is available.
4. Presentation monitor. This is a 1920x1080 screen intended for slides.
5. RDP/Laptop monitor. When running client proprietary material, I must either RDP/Citrix into a desktop or use a client-provided laptop. The RDP session, or laptop, is connected to this monitor. It is 2560x1440, so only a 1920x1080 region is captured. This allows the ‘unused’ portion of the screen to be used for other purposes. It also means that the captured region can be somewhere where pop-up messages will not appear.

Teleprompter

The teleprompter has undergone some substantial upgrades. Initially, it had a small screen so I could see everything without my eyes darting around. The 7" screen was just too small in practice. It now has a 15.6" portable monitor and an upgraded camera. I still maintain that a good microphone is more important than a good camera, but I had a chance to improve the camera, and I took it.

The hole at the back of the teleprompter was initially cut for a different, larger lens. That lens was faulty and was returned, but it left the teleprompter box with a hole that was too large. A 3D-printed shroud was created. The lens doesn’t fit 100% snug, although that was the original intention. With it being a little loose, I can see a ring of light behind the teleprompt screen. But I can only see the ring of light when my eyes align with the camera. It turned out to be a helpful guide.

Reliability

I built the Mk III in 2020, and it has served me almost faultlessly since then. However, at the back of my mind, I always feared that something would fail. A failure on the teaching station would be more than an inconvenience for me. I may have over 100 attendees that will have to wait until I found a fix (stressful!), and I might lose business.

There were three main areas of failure I was concerned about:

1. one of the monitors failing, particularly the tiny screens which were not as off-the-shelf as I would like,
2. one of the many power supplies failing,
3. and the main machine, or a component within it, failing.

On the Mk III, there were two 10" screens and one 7" screen built from LCD panels ordered specifically because they were small. These were driven by their own 5V power supplies. If any of these failed, they would not be easy to replace, and I had no spares. I have packed the 7" screen away. I now use one of the 10" screens as the top monitor (2) and have the other one on standby if necessary. The presentation screen (4) and the teleprompter screen (3) have been replaced by 15.6" portable monitors, and I have a spare. I can cope with the loss of one of the other monitors.

For power supplies, I consolidated them using a
6 port desktop charger. Monitors 2, 3, and 4 need 5V power, as do the clocks and light. Should this fail, it can be replaced by a bunch of USB adapters. It’s not like every house has any of those spare!

If the computer fails, then I won’t be able to fix it quickly, and having a spare machine would be too much work to maintain. I do have an alternative, though. It deserves its own post in the future, but I also have a portable teaching station based on a laptop, an iContact Camera, a USB capture card, and the spare portable monitor. I can have that working in twenty minutes or so.

Keyboard

You may look at that and scoff at the complexity. Surely you could use a KVM switch and just have a single keyboard and mouse? Yeah, I tried that. It worked well for a couple of hours – until I switched, and Windows decided that every device needed to be re-enumerated, which meant that OBS lost its USB cameras!

The riser has dowels that locate into the desk and into the boomerang board. This prevents slippage, and the keyboards can be taken off together quickly.

3D Printing

I didn’t have access to a 3D printer for the Mk III, but I did for the Mk IV, and it’s a game changer. For example, I was having trouble attaching the microphone securely. But a 3D-printed clip not only allows a perfect, secure mount, but it also allows the microphone to be detached very easily.

Background Screen

As with the Mk III, I have a painted plywood panel that hangs behind me to give a uniform colour or green screen. The Mk III one was quite large and heavy, which wasn’t a problem until I was diagnosed with psoriatic arthritis. I knew it would only be a matter of time before lifting it above my head while trying to insert a toggle would be too painful.

To use the background screen, I lower the carabiners, attach them to the background screen and then hoist up each side iteratively. The CamJam is a friction ratchet that prevents the paracord from slipping back unless you pull the cord out at an angle. It’s secure and easy to control. When finished, I pull the paracord out of the cam (that would be a pull towards the viewer for this photo), and then lower each side of the background screen and unclip the carabiners from the screen. The carabiners can then be clipped together, and the cords can be tied to stow them above head height.

I found that there were two different sizes of CamJam. I tried both but could only reliably release the cam in my setting with the smaller one. The background screen weighs a lot less than the maximum load of each CamJam.

Things Retired

Not everything from the Mk III made it over to the Mk IV.

I had the idea of floating camera controls – I could easily control the picture-in-picture elements so that I could, for example, float the main camera around a code review, positioning myself next to the code in question. Unresolved hardware problems stopped me. I still think it’s a fun idea, but clearly it’s not essential.

Although I still have a large bank of sound effects, I don’t tend to use them these days. The novelty has worn off. I keep them on hand for the right audience, but there are very few buttons on the Main Stream Deck page.

I now use PenAttention for pointer highlighting.

The Mk III had a neat slide-down Wacom tablet, but that has now been replaced with a simpler, larger BT Wacom tablet. I rarely use it, though, preferring to draw on paper.

Summary

The Mk IV is, in most respects, an evolution of the Mk III. The biggest change is better preparation for component failure. I know you should never say never, but I think this may well be the last major version of the teaching station.