New Year, New Development!

Intro

Hi everyone, Cooper here! We're back with our second monthly update on development and the state of Rack Robotics. We've made a lot of great progress since our last update and I'm very excited to share it all with you! As of now, we're still on track for Q1 of 2025 delivery of pre-orders.

If you're enjoying these updates and want to chat with members of the Rack Robotics team and community, please join us on our Discord chat! We'd love to see you there.

Betta Wire

There has been a great deal of development on the Betta Wire since last month. We have completed initial kinematic testing of the new coreXY design and have been brainstorming the overall construction and user experience of the machine. We have also made significant progress with the new and updated toolhead and firmware.

Kinematics

Kinematic testing has revealed that we will almost certainly be able to hit our motion accuracy and precision targets. Testing of motion was conducted on the top and bottom XY gantries. We have a goal of being able to achieve 50 micron motion accuracy and we have collected data suggesting that we may be able to do even better than that.

Coming up, we'll be conducting further testing on this with a more automated form of data capture. This automated data capture will allow us to easily 100x the number of samples we can capture in testing, giving us far better data on the subject.

User Experience

A lot of thought has been put into user experience recently. The primary things are concerned with are:

• Dielectric management
• Wire Feeding
• Waste Wire Disposal
• Machine Control

Something nice that has recently been figured out in the 3D printing world is the ideal position for filament spools. Largely, it seems that the community prefers side access of filament when compared to rear sided access. Ideally, we'll be able to place wire supply on the side of the machine. We also intend on placing the waste wire receptacle on the side of the machine.

Wire feeding and waste wire control have also been looked at. We have some nice ideas for this. We won't discuss those at the current time, but we're sure you're going to like them.

Toolhead

The toolhead has made a significant transformation in the past month! Overall volume has gone down quite a bit and ease of assembly has gone way up.

We've done something fun with it, too! We're working now on integrating hole popping into the toolhead. With integrated hole popping, more complex and multi-profile parts will become much easier to make. John and I have been collaborating on overall tool layout and design for this one and I'm quite happy with how it's been turning out.

There's a huge amount of complexity per unit volume in any compact desktop machine toolhead, that goes double for toolheads that integrate multiple processes and fluid management! This has lead us to work on a new CAD workflow based on ideal positioning of all stock and custom components prior to buildout of 3D prints.

Here's a screenshot of most of the components required for the design without the 3D prints:

We should have a working unit ready for testing in the next few days.

Firmware

We recently had Nick doing a spike into Klipper to see if we could make 4-axis control work. This work went for most of the past month and we even worked with the Danger Klipper team. This has decidedly not gone well (through no fault of the Danger Klipper team).

Our difficulties with Klipper firmware have lead us to a firmware that we considered, but ultimately passed over early last year. LinuxCNC.

LinuxCNC has a number of advantages over Klipper firmware:

• Real time motor control
• Built in allowances for closed loop actions
• Full rearward g-code control

If LinuxCNC works well (and it seems to!), we'll have much more precise and fast motor control in relation to the conditions of the WEDM spark gap. Additionally, we'll have the ability to have the machine automatically back up during poor conditions.

It has only take a few days to get real time 4-axis controls running on LinuxCNC, so things are looking really good on the firmware side.

Powercore

Development of the Powercore is moving steadily. John has been taking this one head on and is doing a great job.

So far, several of the test modules have arrived and have gone through validation. Much of the original boards have worked out perfectly. Some issues were found, and some issues have been rectified with new boards on the way.

The overall size of the Powercore is going way down. We're expecting a safer, quieter, and easier to use unit at the end of the required updates. We're taking this opportunity to integrate more safety features and more thorough control features. We're super excited to finalize these updates and get this unit through compliance testing. We expect compliance to go well too as we've been taking pains to reduce EMI output.

Closing Thoughts

We're making solid progress. At the moment, we don't have any items that feel totally unknown or like potential roadblocks. It feels like we have a ton of work to do, but it's mostly just going to be grinding for the next period of time.

We're going to be learning a few new things when it comes to tooling for mass production of some small components. That can be a little intimidating, but we have a great partner in LDO Motors and we look forward to our continued cooperation.

There's been some concern about the price and availability of international components in the coming year, and this is something we're well aware of. While we've been gaming out different ideas, there's not much to commit to at the moment. We just have to continue development and to keep up to date on tariff and trade rules for the time being.

We're very happy with the current progress of the project and our products. We thank you for your continued support of our team throughout 2024 and into 2025. We think you'll really enjoy what we come up with this year!

-Cooper