Hey everyone!

It’s been a little while since we’ve talked about what’s going on under the hood of the SuperLongBoard (SLB), and today we’ve got some exciting news for those of you who like to live on the bleeding edge.

We are looking for a small group of AltMill and LongMill owners to help us beta test the new “Main” version of the grblHAL firmware.

If you’re interested in helping us test this out, you can fill out the Google Form linked at the bottom of this post. But first, a little history lesson on how we got here, why this change matters, and what you can expect.

A Quick History Lesson: SienciHAL vs. Main

When we first launched the SLB, we made the decision to fork the firmware into our own specific flavour, which we affectionately called “SienciHAL.”

At the time, we needed to make sure the firmware was rock-solid and perfectly tailored to the specific hardware we were building. We needed to guarantee stability for our users right out of the gate, and having our own branch allowed us to lock things down and ensure everything behaved exactly how we wanted it to for launch.

However, maintaining a separate fork means you miss out on all the cool new stuff happening in the wider world of grblHAL development. Over the last year, we’ve been working closely with the original creator of grblHAL (Terje) and the community to bring our specific needs and features into the Main branch of the firmware.

Our goal has always been to contribute to the open-source ecosystem, not just take from it. By working to get our changes merged into the main project, we ensure that the SLB remains compatible with future developments while being able to contribute any potential improvements back to the community.

What’s New in this Firmware?

For the most part, if we’ve done our job right, you won’t notice a huge difference in how your machine cuts. The motion and reliability should feel just as solid as before. However, moving to the Main branch unlocks some nice quality-of-life improvements and future-proofing features – examples being:

Automatic Motor Alarm Reset: One of the small but mighty changes. It makes recovering from motor alarms much smoother without needing to power cycle or mash reset buttons as frantically.

SD Card Support: We are unlocking support for SD card reading, which opens the door for running files directly from the board and other advanced standalone features down the road.

Advanced Plugin Support: This firmware includes support for the plugins we’ve developed for our ATC (Automatic Tool Changer) spindle. We also hope that these features will be helpful for anyone setting up their own automatic tool change system on any machine running grblHAL.

Under-the-hood Tweaks: A lot of small improvements to stability and code efficiency that come from the collective brainpower of the open-source community. This firmware version also exposes the ability to change many other settings and features such as LED brightness and ‘jerk’ motion control.

Who Should Test This? (And Who Shouldn’t)

We are looking for AltMill and LongMill users who are relatively comfortable with flashing firmware and using gSender.

This is beta firmware. While it has been tested to the best of our abilities and equipment, there is naturally a risk of bugs or unexpected behaviour.

It is not recommended to participate in beta testing if you’re in the middle of a critical production run or have a deadline to meet.

DO sign up if you enjoy tinkering, don’t mind providing feedback, and want to help us polish the next generation of our software stack!

For Interested Beta Testers

If you’re interested in beta testing, please fill out the Google Form below. We will be selecting a limited number of users to start with to ensure we can provide adequate support and gather focused feedback. If selected, we’ll email you the firmware file and instructions on how to flash it to your SLB.

For Everyone Else Interested

For anyone interested in upgrading without beta testing, an officially supported public release of the new grblHAL main firmware will be made available in the coming months, shipping with new machines as well. We will announce this in a subsequent blog post and on social posts.

We’ve also been working to coordinate to have a ‘Webbuilder’ accessible grblHAL machine profile accessible that will allow advanced users to configure their version of this firmware any way they’d like to.

We are incredibly grateful for open-source projects like grblHAL. They are the backbone of what makes affordable, high-performance CNC machining possible for hobbyists and small businesses. We want to do our part to support and contribute to these projects wherever possible, and moving our users to the Main branch is a huge step in that direction.

The AutoSpin T1 is an exciting new product designed to mash spindle capabilities with a traditional router. In a way, you can think of this as a replacement for the Makita RT0701 router that has been the staple for so many hobby CNC machines. 

It also serves as an intermediate product for users considering a spindle. The AutoSpin T1 offers speed control and on/off functionality through a signal cable similar to a spindle, which allows several benefits including:

• Improved safety, as the router can turn off when a cut finishes or is cancelled
• On the fly router speed control, allowing users to change the speed without touching the router
• Added convenience of being able to automatically turn on when a job starts

While spindle systems have continued to gain in popularity, many entry level CNC machines still continue to use a Makita RT0701 or similar style router. The AutoSpin T1 aims to cater to our most entry level and budget-sensitive group of users.

We initially designed this with the LongMill in mind, but we also recognize this style of router is commonly used in other machines, including Shapeokos, Onefinitys, XCarves and more. With the help of some of our broader community members, we’ve tested the AutoSpin T1 compatibility with many other hobby CNC machines, which means we can bring this technology to many more people.

Development

Although the concept behind the T1 is simple, this project is a culmination of many, many months of research development.

One of the key reasons for us to develop this router started when we experienced a small batch of Makita RT0701 routers having overheated bearing issues. We found that after a few minutes of use, some Makitas would have extremely hot collets, which we suspected was due to friction from the bearing holding the shank. Upon autopsy of the routers, we found that Makita started using bearings from two different manufacturers, one of which was the root of some of the overheating problems. 

This actually became such a growing issue that we actually ended up discussing bearing issues with product managers at Makita. We also did a ton of research and testing on different bearings and styles to ensure that when we went to build our own router it would not have the same issues. Given that we bundle a Makita router with most of our LongMills, we knew that we would have a large enough volume of AutoSpin routers to produce as replacements, which provided the motivation to develop our own.

Up to this point, the Makita RT0701 has, and still continues to be an extremely reliable router. We’ve had very few issues overall, even counting the overheating bearing issues. While we initially considered moving away from the universal motor system that the Makita uses, we eventually came back to the same system given how reliable, well used and inexpensive it was compared to other systems.

Speed Control Optimization

One of the most powerful features of the Makita router is its ability to compensate for load changes. With a traditional, uncontrolled motor, as soon as a load is applied, the speed of the motor goes down. In a CNC application, the load on the motor changes constantly, but the speed of the motor must stay the same to ensure that the chipload of the end mill can stay the same. This is especially difficult because the slower the end mill turns, the higher the load on the motor gets, which means that with an uncontrolled motor, a stall can happen pretty quickly under heavier loads. 

What we found was that the speed control of the Makita router was actually extremely good, with compensation happening less than 3/10ths of a second.

Given that we were working on building our own custom electronics to allow for the use of PWM speed control, a lot of tuning went into the motor to ensure a fast response. 

Lastly, with regards to PWM control, we also found out that we needed to ensure that our electronics supported a wide variety of PWM signals. We found that each controller had a different signal speed, which meant that we needed to ensure the motor controller itself needed to be able to interpret the signal reliably.

CNC Compatibility

Given the popularity of the Makita RT0701, we naturally built the body size of the router at 65mm and most of the shared dimensions. However, differences include:

• A longer cable
• Detented speed potentiometer

Additionally, we’ve created the wiring for the PWM signal cable to be adaptable with factory provided plugs to allow plug and play functionality with most common hobby CNC machines. Users can also hardwire their PWM signals.

Safety Compliance

To ensure that the product is safe and can be sold in North America, the AutoSpin T1 has been certified under UL1004-1 standards. Additionally, we believe that the AutoSpin is safer than the typical router, as it can be shut off and turned on remotely through the controller, which means that if the machine needs to be stopped in software, the controller can (and should) be configured to turn off the router automatically as well.

Who is this for?

The AutoSpin T1 is directed as a default option for low to middle end hobby CNC machines or a drop in replacement for hobby CNC machines that already use a similar 65mm size router. Here are some of the key features:

• ER11 collet system, allowing for use of a standardized and readily available collet system
• Higher quality bearings ensuring smoother operation and longevity over budget routers
• Signal wire, allowing most hobby CNC controllers to control On/Off and speed between 10,000 to 30,000 RPMs, as well as the ability to be controlled manually
• Longer AC cable

Controller Compatibility

The AutoSpin T1 has been tested with:

• Masso controller
• Buildbotics controller
• The LongBoard (found in the MK1 and MK2)
• SLB and SLB-EXT
• Carbide 3D controller

Thank you to our beta testers for their testing and feedback!

Virtually any controller that has a 5V PWM output for spindle control will work with the AutoSpin T1.

The AutoSpin T1 can also work independently without using the controller for speed control. The AutoSpin T1 can be turned on and off, and have the speed be controlled with the potentiometer dial at the top of the router. To ensure reliable operation in manual mode, the potentiometer dial is detented, which prevents the dial from moving during cutting and high vibration operation.

Spindle vs AutoSpin T1

There are notable similarities and differences between spindles and the AutoSpin T1 that can help you determine what is right for you:

• Spindles are generally more expensive than the AutoSpin
• Spindles require more complicated wiring and setup
• Spindles are generally quieter and efficient, and can output more power
• Both can be turned on and off, as well as have their speed controlled by the CNC controller

The AutoSpin T1 is best for users who:

• Want to have their setup be as simple and compact as possible
• Already use and are happy with the power and versatility of a router

Addressing Power Ratings

One of the biggest general considerations users will make between a router and spindle will revolve around power ratings. We believe the way that power ratings are advertised in the industry can be misleading and don’t tell the full picture of how a motor performs in real life.

Wattage: Most spindles and routers will have a power rating in watts. Common wattages are 1.5KW and 2.2KW for some entry level spindles. For the Makita RT0701, you’ll see 1.25HP as the rated power. For all of these ratings, they typically indicate the peak input wattage. This indicates the maximum amount of power the motor can handle for a short period of time. This doesn’t indicate how long it can handle it for or under what conditions. 

Like car engines, there is a relationship between power output, torque and speed. In a standard 3 phase spindle, torque generally remains flat in the operating speed of the motor, and only reaches peak output power at its maximum speed. This means that the spindle at a lower RPM does not fully use its capacity.

For the universal motor in the AutoSpin T1, the torque of the motor is highest at its minimum RPM, and diminishes as the speed increases. 

In practice, this means that a router can actually perform quite well, especially at lower speeds. As you can see in the graph, the green line shows the line power output of the Makita RT0701 and the blue line shows a typical 1.5KW spindle. And as we’ve noted in our tests, the cutting performance actually lines up with the tests, where it is easier to stall a spindle at low RPM compared to a router. 

Another thing to note is the rating system used for power tools in general. You can often see tools rated for 1.25HP, 2HP, and even 3HP at times. Based on a typical 120V 15A outlet found in North America, we can reasonably expect 1800 watts, or about 2.4HP. The reason why power tools can be rated so high is because a circuit can handle above 1800 watts momentarily without the circuit tripping. So as we mentioned earlier, these ratings are for peak power, not average or constant power. 

Due to this, in the eyes of the certification, the motor is only “rated” for an output of approximately 350 watts at 30,000RPM, even though in practice, this can vary widely.

All this is to say that in practice, when working with typical tooling up to ¼” (which is what we expect most users to be working with the ER11 collet system) users will find the power of the AutoSpin more than adequate.

Makita RT0701 vs AutoSpin T1

There are also some notable similarities and differences between the Makita RT0701 and AutoSpin T1:

• The cable on the AutoSpin T1 (14ft / 4.3m) is longer than the Makita RT0701, which makes it more suitable for CNC machine use.
• Both use similar components and have very similar form factors.
• Both have a 65mm diameter body, making it compatible with any 65mm router mount.
• The AutoSpin T1 can be controlled with a PWM signal, found in most hobby CNC controllers. This allows the AutoSpin to be turned on and off by the controller, plus, it can adjust and change speeds on the fly.

In a way, the AutoSpin T1 is an improved version of the Makita RT0701 and serves as a drop in replacement for customers who want to add features to their machine with minimal changes.

Production Schedule

Beta testing was conducted and concluded in mid-2025.

We are now in production for the AutoSpin T1. We expect units to arrive late January and to start shipping out by mid-February.

Pricing

The AutoSpin T1 router is positioned at a competitive price point to the Makita router:  $149 USD / $199 CAD (vs $119.99 USD / $165 CAD.)

We’re excited to launch the Closed-Loop Stepper Motor Kit to the community. The Closed-Loop Stepper Motor Kit (CLSM Kit) is a complete kit including the motors, cables, controller and other hardware required to convert any LongMill MK2 or MK2.5 to use closed-loop stepper motors.

Order your kit here: https://sienci.com/product/closed-loop-stepper-motor-kit/

Contents of the kit

Each kit comes with all of the components needed to convert a LongMill MK2 or MK2.5 (any size) to a closed-loop motor system.

• One (1) SLB-EXT Closed Loop Controller, plus:
  • Independent e-stop with 3 customizable action buttons
  • 2.5m e-stop cable
  • 1m USB-C to USB-A cable
  • Mounting brackets
• One (1) 48V 10.4A Power Adapter
• Four (4) NEMA 23 Motors and new motor covers
• A drag chain (1000mm) to accommodate any size LongMill, plus drag chain brackets and holder mounts
• Four (4) inductive sensors with mounts for Y-axis
• Sixteen (16) 40 mm blue aluminum standoffs
• Motor cable set (x1 long, x3 short)
• M5x12 bolts
• M5 washers, nylock nuts and t-nuts
• M5x55 screws (for use with the LongMill dust shield)

Resources

Complete resources for installing the CLSM Kit to the LongMill can be found on our Resources site: https://resources.sienci.com/view/lmk2-closed-loop-steppers-2/

Specifications

Motor (Frame) size: 57mm

Motor torque: 1.2NM 

Motor max speed (RPM): Approx. 1500

Voltage: 48VDC

Length: 56VDC

Cable Lengths

X cable: 1.8 m

Y1 cable: 1.4 m

Y2 cable: 2.7 m 

Z cable: 3.65 m

Measured from the 2×4 AltMill cables which we are using for this kit. 

Changes to the Industry

In recent years, we’ve slowly seen a shift for hobby CNC machines to adopt the use of closed-loop stepper motors. We’ve also seen a shift in the price of the motors coming down over time as well, with the price for an open-loop stepper motor and external driver now at similar levels. 

We still see open-loop steppers used in pretty much all budget and entry level CNC machines, but we expect this to change over time as the demands and expectations from the CNC community continue to grow. We also expect as the popularity of closed-loop steppers grow and prices come down, that most machines will start to use them.

Cost of Development and Open Source

We don’t keep exact tracking of how much time and money we’ve invested in this electronics ecosystem, but I would guess at this point we’d be looking at least a million dollars. This includes the development of the controller and electronics themselves, testing of the motors, and development of gSender. We recognize that for many up and coming CNC manufacturers and developers in our space, investing that much into development is not possible.

Pushing this ecosystem to a wider audience should allow CNC manufacturers and developers in our space to get a head start in pushing the ecosystem further and potentially scaling up where they can contribute to future generations of CNC companies.

A good example of this is Masso’s initial decision to move to a subscription model for updates, then a sharp retraction after backlash from the community (https://www.reddit.com/r/hobbycnc/comments/1jtfbkd/maso_reverses_course/).

While this situation changed course in the right direction, it does shed light on the fact that close source CNC control ecosystems reduce the control users and manufacturers have in a core part of their machines.

So why do the fact that our systems are open source matter? Well, it means that if we disappear from the face of the earth, users and companies can replicate and develop atop existing designs and code. We can’t make you pay more for what is already free and openly available. 

Some folks may see allowing others to use and duplicate our designs as a potential danger to our business. However, the way we see it is if someone else can make what we already make cheaper or better, it would serve us to use this development for ourselves as well. The fact of the matter is that developing a CNC company is so much more than just the designs themselves. It’s also the resource development, customer service, community, and continued innovation that needs to be there in every company to succeed.  

Closed-loop Steppers vs Open-loop Steppers

Closed-loop stepper motors are simply faster, more accurate, more efficient, and more powerful than an equivalent open-loop stepper motor, with the added benefit of being able to detect when it loses steps. This also adds another layer of safety, as our control systems automatically shut off attached peripheral devices like spindles and lasers when the machine loses its position. 

How does this work? Well, with an open-loop stepper, you can think of the motor having a “cog.” When we want to move the motor, we send it a signal to move a single step forward or backward. In the case of most standard stepper motors, there are 200 “steps” in a motor (there’s also something called microstepping but we won’t get into that today.) By sending a specific number of step signals at varying speeds, we can control the angle of rotation specifically and the speed of the rotation as well.

When the system works without being overloaded, the system works quite well. However, when a load exceeds the amount that the motor can handle, the motor “skips a step.” This means that the cog goes out of line and the machine loses it’s position. However, because there is no feedback system in the motor, even if the motor loses its position, the motor will keep moving.

The reason why an open-loop stepper is less efficient than a closed-loop stepper is because not only do you need to move the motor forward, you also need to apply a force to keep it from overshooting its position. This is to say, if you wanted to move the motor a full rotation by sending a signal to move it 200 steps, it also needs to consume power to keep it in position so that the motor does not overshoot into the 201st step.

Closed-loop steppers on the other hand are structurally the same as an open-loop stepper motor, with the exception of having an encoder built onto the shaft that allows the microcontroller to measure the position of the motor continuously as it rotates. This means that the motor can act more like a bicycle, allowing the motor to coast in the position it needs to be, and apply a varying amount of power to keep the right speed up. By comparing the position of the motor using the encoder with the position the controller requires, it can adjust its position thousands of times a second.

When the motor becomes overloaded and the motor is no longer where the controller expects it to be, an error message is sent to the controller by the motor which allows the machine to emergency stop.

Since we use closed-loop stepper motors with an integrated driver, this also improves repairability and compatibility with many different types of systems as we can swap just the motor, and the driver and electronics inside the motor are specifically tuned for the motor itself. Using external drivers like on the SLB and the original LongBoard (used on older generations of the LongMill) it can be a bit trickier since different motors have different performance characteristics. This is why we tune the drivers to work best with the original motors, but when it comes to compatibility with other, non-Sienci produced motors, we can’t predict the performance.

Economies of Scale

One of the big advantages that we have is that unlike independent manufacturers of controllers, we already have an established volume of production (our machines) that allow us to get to higher economies of scale. 

Offering the CLSM Kit for the LongMill is our first step in unifying the technology stacks between the LongMill and AltMill lines, and committing to closed-loop motors on all our machines. This allows us to leverage even larger levels of economies of scale, allowing us to reduce our production costs even further.

We’re also able to leverage economies of scale into the optimization of the motors themselves. In our first batches, we were using off the shelf motors with standard tuning. However, with a recent issue from a new batch of motors that requires us to reflash and reprogram the motors, we started delving into further motor tuning that will in the future allow us to optimize motor performance for our line of products. If we were dealing with a small number of motors, it may not be economical for us to focus on tuning those motors, but if we’re dealing with a large number of motors, we can spread out those efforts more, making the cost of tuning less per-motor.

Right now the CLSM Kit uses the same motors as the AltMill 2×4 and 4×4 (Z axis motors) and shares cabling with the AltMill 2×4. We expect to see some interchangeable use of parts between the AltMill and LongMill lines as we continue to develop these products into the future.

Future plans

The closed-loop stepper motor system and SLB-EXT systems are a great, feature-filled, proven platform for mid-level and semi-professional use. However, we do acknowledge that it’s expensive for entry-level hobbyists. One of the projects we intend to work on is to create a more affordable version of the SLB-EXT and peripheral electronics that fit better with hobby level machines. This will open up some new possibilities with developing more affordable, entry-level machines.

We also believe that opening up the use of our electronics platform and software will open up new possibilities for people looking to update and upgrade their existing systems, as well as supporting emerging CNC manufacturers to integrate our systems into their own machines, reducing their cost of development.

Pricing

The complete kit is available for purchase for $560USD/$795CAD. Kits are expected to start shipping out in around 2 weeks from time of purchase.

FAQs

What machines can I use this kit for?

We have specifically designed this kit for use with the LongMill MK2 and MK2.5. Each kit comes with all of the hardware and electronics needed to make this conversion. 

We believe that this kit can also be used with non-Sienci built CNC machines, such as DIY kits and other hobby CNC machines. However, we do not have resources and guides to help customers on the assembly process at this time. 

Does it come with software?

The CLSM Kit comes with the SLB-EXT which is compatible with our free, open-source, and powerful control software, gSender. This allows users to use the full range of gSender features.

Can I buy a LongMill now with the CLSM kit instead of the open-loop motors that come by default?

At this moment, no. We are planning to release a LongMill MK3 in 2026 that will offer the LongMill with closed-loop stepper motors as the default option. TBD on announcement and launch plans but news should come out sometime in the spring. Stay tuned for future blog posts and news via our socials.

If I have a SLB already, can I use that instead of the SLB-EXT?

Unfortunately, no, the SLB does not have the motor connections that allow it to interface with the closed-loop stepper motors and the power distribution circuitry to power all of them.

Why is the LongMill MK1 not supported?

Given that there are much fewer LongMill MK1s currently in the wild, and the mechanical structure of the machine is less suitable for more powerful motors, we opted to focus on only supporting the LongMill MK2 and MK2.5. 

Do you have any drawings so I can adapt to another brand CNC?
Yes! You can download all plans here.

Probably one of the most requested products we’ve gotten in recent years has been an auto tool changer. While the concept seems simple, the actual execution of an ATC system is extremely complex, especially as both the software and hardware must work in concert perfectly to ensure that tool changing is fast, simple and reliable. It’s taken quite a while for us to get to the point at our company to develop the engineering manpower and funding to be able to undertake such a complicated project. 

I can safely say that the ATC is by far the most technically challenging product we’ve developed, but we’re excited to share it with the world as one of the most affordable, full featured CNC spindles with an auto tool changer. We believe this paves the road towards not only mechanical and electrical advancement, but also that the development in the user experience and systems design of the software experience takes this type of product to the next level.

The ATC is a spindle with an integrated auto tool changing functionality which works with gSender to provide a seamless experience in changing tools. Users are able to load and remove tools with a press of a button (manual mode) or by ejecting and loading tools onto a rack. 

Who is this for?

The ATC was designed for users that aim to improve their productivity with their CNC machine by automating the tool changing process. We believe that the best fit for this product are users that have experience with their machine and CAM programming, and want to get into small to medium scale production. 

The ATC system is designed to be plug and play with any AltMill system, including the MK1 and MK2 2×4 and 4×4, plus the new AltMill 4×8. This makes it particularly attractive for users that want to get up and running with an ATC system as quickly as possible.

While we know that lower cost, collet-changing based ATC systems exist, we chose to focus on the ATC spindle system instead because we believe that this system will work at the level of reliability and performance that is required to our standards of being able to do hundreds and thousands of toolchanges without error.

We do also acknowledge that this product falls outside of the realm of a price point affordable to the average hobbyist, and we expect our general demographic to be folks that have higher expectations from their machine.

How does it work?

The ATC is essentially a spindle with additional electromechanical systems that allow for the change of tools controlled by the CNC controller. You can almost think of it as a spindle with extra hardware attached.

A system of pneumatic solenoids activates a piston which allows the tool to be pulled in or released during a tool change. Each end mill is mounted to a ISO20 tapered tool holder which allows the reliable interface with the spindle. As the ISO20 tool holder is a standardized design, virtually all high quality tool holders will work with the ATC.

Integration with gSender

One of the most important aspects, and what makes our ATC unique compared to nearly all other ATC systems, is the native integration with gSender. This allows functions such as:

• Automatic switching between automatic and manual tool change modes when the tool rack is removed or not detected
• Added safety features and warnings such as low pressure, tool missing and temperature
• Optimized tool loading and loading motion planning
• On-the-fly changes to tool holder position mapping
• Colour assignment in the gCode visualizer based on tool
• “Run-from-tool” functionality, which allows users to run toolpaths specific to each tool

…and more.

Engineering the ATC

The ATC comes with a series of unique engineering challenges:

• The use of low pressure air
• To have maximum reliability
• Sensor integration
• Installation and integration

Custom PCB

To integrate all of the communication and sensors into the ATC, we developed a custom PCB board that lives on board the spindle. One of the most notable features includes the LED status button, which shows the status of the spindle based on its colour, as well as allowing the user to use the button for functions like executing a manual tool change. 

Quiet Cooling System

Since we first started building spindles, we’ve felt pretty strongly that air cooled spindles are the best choice for the majority of people for these reasons:

• Watercooling relies on an external pump, which adds a significant failure point. A failed or disconnected water pump can cause the motor to overheat and in the worst of cases, the wiring to burn out. Most air cooled spindles on the other hand (although not the ATC specifically) use a mechanically mounted air impeller that drives air through the spindle to provide cooling. The ATC specifically uses an electric cooling fan to do the same job as the impeller, but uses a combination of a temperature sensor and controller to adjust the cooling and turn off the fan automatically. 
• Watercooling requires a send and return hose looped through the drag chains, requiring not only hoses but larger drag chains as well. This adds additional cost and set up complexity. 

By using a separate electric cooling fan, we are still able to get very low levels of noise, as the fan runs at a lower RPM in comparison to a mechanical air impeller. Additionally, since we can turn the fan on and off as needed, this impacts the overall noise of the spindle as well. It should be noted that the fan will primarily turn on when the spindle is running and cutting, where the sound of the spindle is masked by the sound of cutting anyway.

Installation and integration

As with all of our accessories, the ease of installation and the focus on a tool to be as plug and play as possible is critical for adoption. From our research, third party ATCs, while many exist, come with a large barrier to entry as the installation process varies significantly based on the type of machine, controller, and tool rack system the user chooses. Given the cost and difficultly of development, we’ve seen a split between ATC manufacturers and CNC manufacturers, where one company handles the resources and integration and the other builds the machine. This means the ATC manufacturers need to work out how to make their systems compatible with CNC machines they didn’t develop in the first place, which makes it more difficult to make it operate as a streamlined and optimized system.

In this ATC project, we have the opportunity to design the machine, mounting, wire management, air management, and software all as a cohesive system.

One of our key accomplishments in this project was also to build a toolrack that was flexible, easy to install, and easy to remove. Given that installing and having an active toolrack reduces the working area slightly, we also wanted to optimize its footprint as well. One important feature is the ease of removing and replacing the toolrack. When users want to use the full area of their machine, users can remove their rack in seconds with two hand screws. In this mode, the ATC can be used manually, where users can press the button on the spindle to release the tool holder, and pushing the button again with another toolholder allows the tool to be secured back to the spindle.

Pricing

Users should expect to invest around $2,600 USD to $3,300 USD before tax for a complete system, including the spindle, VFD, rack, and toolholders. Users should expect to pay around $150-300 USD for an air compressor, which is needed for this system, if they don’t have one already.

• ATC 6-Tool Kit: $2,890 USD / $4,040 CAD
• ATC 12-Tool Kit: $3,340 USD / $4,670 CAD
• ATC Spindle Only Kit: $2,590 USD / $3,620 CAD

Additionally, our new “Clear Cut Dust Shoe” was specifically designed for all of Sienci Labs’ lineup of spindles, and comes standard with the ATC. This allows for tool changes to happen without any interference from the dust shoe.

Additional add-ons are available as well:

• Separate Tool-Rack: $245 USD / $340 CAD
• Single Tool Holders: $28 USD / $38 CAD
• Air Filter Regulator Kit: $80USD / $120 CAD

All available products are sold here

Air compressor compatibility

For proper operation of the ATC, users must provide a reasonable sized air compressor, with 3 CFM at 90psi or better, and 100psi minimum. The ATC spindle will only consume significant amounts of air during a tool change, but not while cutting, which keeps compressor requirements minimal.

FAQs

Some common questions are below but on Thursday, December 4, our project lead engineer Johann will be hosting a Q&A with Kevin our lead gSender software developer, and will answer any technical or work flow questions you may have. Watch for more formal announcements but you can quickly find live the streams on YouTube.

And if you haven’t already, check out what all the engineers have to say in this breakdown video:

Does the ATC work with the LongMill?

Due to weight and mounting constraints, no. The ATC is not compatible with the LongMill.

Why do I need an air compressor?

The air compressor is needed for several functions on the ATC, including supplying power to engage and disengage the tool holding mechanism, as well as providing a de-dusting function, where a blast of air is shot onto the tapered part of the tool holder to ensure that dust and debris have been removed before loading a tool.

Can I get the tool length sensor separately?

As discussed earlier, the tool rack system integrates a tool length sensor to calibrate the Z position of the tool, as well as confirm the existence of the tool itself. We will provide the tool length sensor for mounting to the machine as a separate add-on at a future date, such that LongMill and AltMill users can automate the process of finding the Z-height of their tool before cutting.

How many tools can I have set up with the ATC?

The ATC and gSender can be programmed to hold 32 tool offsets (coded into grblHAL core.) However, we believe one of the 6 or 12 position holders provides an adequate number of tools and fit within the working area of the machine.

Does the tool rack take up some of my working area from my machine?

Yes, the tool rack takes up a few inches of space in the Y direction. However, during the development of the AltMill, due to our anticipation for this to be the case, all AltMills come with some additional travel space beyond the listed capacity so that in practice, the impact is minimal. Additionally, the tool rack comes with an easy installation and removal system, which means that tool racks can be installed and removed in minutes, allowing users to get the extra space for tiling and other pass-through jobs when needed. The system intelligently detects when a rack is removed and prompts the user to swap tools when needed using the manual tool change button on the side of the spindle.

Is the ATC air cooled or water cooled?

The ATC is air cooled. We have specifically chosen to use an air cooling system to reduce the complexity of the system for the user and integrate additional functions such as automatic control over the fan, based on the spindle’s cooling needs and to provide quiet operation when not in use. A temperature sensor built into the spindle provides an additional safety mechanism to prevent overheating. 

It should be pointed out that both air cooled and water cooled systems are both designed for full duty cycles, which means that the cooling system is scaled in both systems to ensure full time use. Neither system is superior to each other with regards to performance or durability.

Is the ATC compatible with other CNC machines?

In theory, yes. We will provide mounting drawings, wiring diagrams, and schematics that may allow users with machines outside of the AltMill family to integrate the ATC into their own system. However, the use of gSender, gControl, and other Sienci specific hardware may be required to use the full capabilities of the tool. We are not providing support for third party use at this time.

Will you come out with more powerful spindles in the future?

Although we do not have specific plans for a more powerful spindle option in the future, we are expecting to work on a more powerful version, especially as we continue to develop our 4×8 line of AltMills and grow our production focused customer base.

Can I take an existing spindle motor and add the ATC parts onto it?

Unfortunately no, due to differences in the design they are not interchangeable.

Can I run the ATC on 110V power?

For the ATC to run properly, a user must provide 220V power and at least 10A. Some users may choose to get a step up transformer which can allow for the use of this spindle with 110V power outlets, but caution should be used to ensure the current capacity of your breaker is not exceeded during operation.