LongMill Benchtop CNC MK2

(15 customer reviews)

From: $1,650.00

The LongMill MK2 is a powerful and affordable hobby CNC router perfect for any workshop.

Scale it to your needs by choosing from one of its three flavors: 12×30, 30×30, and 48×30.

The machine name roughly corresponds to its cutting area in inches and each machine has 125mm (~4.9″) of Z-axis travel.

Not sure what you need to order for your LongMill? Try our step-by-step LongMill MK2 Configurator!

What sets the LongMill apart:

  • Simple and reliable design ➜  custom aluminum extrusions and  thick steel gantries make for a rigid and dependable machine
  • Lead screw driven on all axes
  • Mounts directly to any surface you wish ➜ freedom to integrate clamps or custom jigs that suit your work style
  • Tall cutting height ➜ don’t be limited when you want to cut large, intricate 3D surfaces or flatten large lumber slabs
  • Proudly made in Canada (power brick is for 120V 60Hz)

Shipping is calculated at checkout.

Order for 12×30 and 30×30 machines have a 2 week lead time. 

Orders for 48×30 machines are expected to ship in July 2022.

LongMill Benchtop CNC MK2

896 in stock


Turn your ideas into a reality with the LongMill Benchtop CNC MK2

The LongMill helps you take your woodworking and fabrication to the next level. Its range of workable materials includes any species of wood, a variety of plasticssoft metals like aluminum and brass, and a variety of machinable foams and waxes for model making or metal casting. Make signs, engravings, mid-size furniture, stands and shelves, wooden toys and games, guitar bodies, and much more! (see more in our Gallery)

We offer our machine because CNC technology opens up a whole new world of making capabilities, especially to those who have a limited shop environment or budget. Our goal is to empower you by giving you access to both a machine that’s capable of a wide range of projects and by assuring you of the assistance that you’ll receive from our team as well as our ever-growing community of machine owners: many of whom started off green to the world of CNC as well but are now happy to share what they’ve learned along the way. (see our Facebook group and Forum). We provide a complete set of resources and instructions to get you on your way to running your first job on your machine.

We designed the LongMill to be the best hobby CNC router in its class, offering rigidity, and reliability, while being easy to put together. With large extruded aluminum rails, fully supported Y-axes, 1/4″ steel gantries on all axes, and high precision MG-12 type linear guides on the Z-axis, the LongMill MK2 is the most powerful CNC router in its class and price point.

Every kit comes with all the…

  • Hardware, rails, lead screws, and gantries
  • Control box, wires, and motors
  • Assembly instructions (online)

Assembly only takes a few hours and can be done with a set of wrenches, Allen keys, and a flat head screwdriver. There is absolutely no soldering. We’ve spent thousands of hours designing and testing the LongMill to ensure that this machine is easy to put together. If you can put together IKEA furniture, then putting together the LongMill will be a breeze.

What do you provide?

  • Your own wasteboard/spoilboard (found at your local hardware store). This is the surface that you’ll be mounting your machine to. See the ‘Size’ tab above for more info.
  • A router (purchase one from us, use one you already have, or find one at your local hardware store/online)*
  • Tools to assemble the machine (wrenches, Allen keys, flat head screwdriver)

For routers, we recommend the Makita RT0700/RT0701. It’s reliable, powerful, is speed-adjustable to a large range (10-30K RPM), and its uniform outer body allows for versatile z-axis mounting. We’ve been using the Makita on our CNC machines for years. The LongMill MK2 comes free as standard with a 65mm router mount, which is compatible with the Makita RT0700/RT0701 and most variations of this router design. If you wish to use a different size router or spindle, please check out the other sizes that we offer.

*Routers that we supply will be 110V only (North America). If you live in a country that uses a different voltage, please purchase a router in your region. 

The LongMill comes with free software and is compatible with dozens of other paid and free software. Try our Toolchain Wizard to get a quick recommendation for software that may work best for you.

Technical Details:
– Laser-cut, 1/4″ steel gantry plates for high rigidity
– Custom-designed, high rigidity extruded aluminum rails on the X and Y axis and MGN12 linear guides on Z-axis
– Delrin V wheels with variable eccentric nuts
– 4-start, 2mm pitch, 8mm diameter ACME lead screw for high torque and fast movement
– NEMA 23 stepper motors on all axis
– 3D printed and aluminum parts
– Mount for Makita RT0701C routers, or request a custom mount size
– 24V power supply (only compatible with North American voltages 110V-120V)
– Arduino board loaded with GRBL firmware
– 4A TB6600 drivers

Our machine uses open-source hardware and firmware, letting users build and modify their machines. Not only that, many of our components are standard and easy to source or 3D printable, making replacing parts easy.

*Router adapters can only be made in sizes between 52 and 80mm.

Additional information

Weight60 lbs
Dimensions8 × 10 × 41.5 in

LongMill Benchtop CNC MK2


12×30, 30×30, 48×30


The LongMill MK2 30×30 has a maximum working area of 820mm or 32.28″ in the X-axis and 868mm or 34.17″ in the Y-axis. The LongMill MK2 12×30 has a maximum working area of 820mm or 32.28″ in the X-axis and 368mm or 14.48″ in the Y-axis. The LongMill MK2 48×30 has a maximum working area of 1280mm or 50.39″ in the X-axis and 34.17″ in the Y-axis. The total Z-travel for both machines is approximately 125mm or 4.9″. Total working area may vary slightly depending on the addition of a dust shoe, inductive sensors, and other add-ons. Please note that dimensions may vary slightly based on assembly and manufacturing tolerances. For dimensioned drawings all of the machines, please download our PDF document. If you’d like to see some tables that our community members have built for their own machines, we’ve got a page on it here: Community Table Builds. If you’re looking to properly size a space to put your machine or are making a dedicated table, ensure that you leave enough room for the LongMills control box and any other peripherals that you might be using like a laptop, monitor, keyboard, etc. The control box is roughly 150mm x 280mm, has holes so that it can be easily screwed or mounted to any surface, and has a USB port on its left side which allows for you to connect your computer to control the machine.


You can include add-ons to improve the functionality of the LongMill. These are all optional. For additional add-ons, please see our Add-On section of our store.

Maktia RT0701 Router

We recommend using the Makita RT0700/RT0701 router 110V with your LongMill. This router comes with speed control from 10,000 to 30,000RPM and has 1.25HP of power. This router is compatible with 1/4″ shank tooling and can be adapted to 1/8″ shank tooling using a 1/4″ to 1/8″ collet adapter.

Dust Shoe

Our Z-axis independent, magnetic dust shoe allows you to attach standard vacuum hoses to your CNC machine, allowing it to suck up dust as it’s cutting, making clean up easier and keeping dust out of the air. This dust shoe is adjustable in the Z direction, and the front bristles and vacuum hose can be easily detached to make it easy to change bits.

Touch Plate

Our 3-axis touch plate allows you to set the ‘origin’ or starting point of your cutting tool very accurately based off the surface of the material you’re going to be cutting. Place the touch plate onto the corner of the material to locate the cutting bit in both X, Y, and Z-directions to start your cutting job, or use it to set the Z-height of the tool to accomplish tool changes on more complicated projects.

End Mill Starter Set

Our End Mill Starter Set comes with a basic set of end mills to get your started for many projects you might have in mind. Each pack comes with:
  • 1/4″ Spiral Up Cut End Mill
  • 1/4″ Spiral Down Cut End Mill
  • 1/8″ Flat End Mill (x3)
  • 1/8″ Ballnose End Mill (x3)
  • 1/4″ to 1/8″ Collet Adapter

LongMill MK2 Dust Shield

Prevent dust and debris from getting into your Y-axis lead screws with our dust shields designed for the LongMill MK2. Each pair of dust shields are made from formed sheet metal which are easily installed between the front and back feet of your machine using M5 hardware. Please note that the ACME lead screws and Delrin Anti-backlash nuts used on the LongMill are designed to work in dusty conditions and the dust covers are not required for general use. Please note that this dust shield only fits the LongMill MK2 30×30.

Inductive Sensors

Inductive sensors allow users to add homing and limit switch functionality to their machines. We only recommend this kit to advanced users


What materials can it cut?

The LongMill can cut materials like wood, plastic, foam, and soft metals. We’ve also had customer cut tougher materials like thin stainless steel and copper sheet.

Where can I buy end mills and other tooling?

End mills and bits are available on sale on our website as well as online such as Amazon and Ebay, or at your local hardware store such as Home Depot or Lee Valley.

What software can you use with the LongMill?

The LongMill is compatible with dozens of free and paid CAM software. The LongMill is compatible with standard G-code. You can check out our resources page at www.sienci.com/resources and look under the software tab. We’ll be hosting webinars and creating additional resource videos to help you learn to design and program your CNC machine.

What system requirements are there?

You can run your machine off virtually any modern laptop made in the last 5 years running Windows, Mac OS, and Linux.

We’ve tested our machine with Intel Celeron and AMD Phenom processors with less than 2GB of RAM with no issues (although it is a bit slow).

For any other downloadable CAD or CAM programs that don’t run on the cloud, please check with the software creator for minimum system requirements.

What spindles or routers can I use?

While we recommend the Makita RT0701/RT0700, you can also use other trim/palm style routers. You will be able to let us know what tool you want to use and we will send you the appropriate mount.

Will there be 4th or 5th axis support?

In the immediate future, there will not be 4th or 5th axis support for the LongMill.

If you would like to implement an additional axis to your machine, we encourage users to try creating their own and sharing it with the community!


The LongMill has a 90 day warranty once it arrives at your door.

We want you to have a great experience with your machine, so if any parts are found to be missing or damaged, please email us. We will ensure that you receive the support you need to restore your LongMill to operating condition or provide a full or partial refund.

You may cancel an order if it has not shipped yet, please contact us if you wish to do so. We do not offer returns for LongMills that have already shipped.

General Warranty and Limits of Service:

Effective March 4, 2019

Throughout this policy the words “we”, “us” and “our”, or “Sienci Labs” will be used to refer to Sienci Labs Inc. herein and “LongMill” or “machine” will refer to Sienci Labs’ Sienci LongMill 12×12, Sienci LongMill 12×30 and Sienci LongMill 30×30. Additionally, the words “you”,  “your”, “user”, and “operator”  will refer to the original purchaser/customer, user, or viewer of any of the products or media provided by or through Sienci Labs.

Sienci Labs Inc. (the “Company”) grants the LongMill (the “Product”) a standard warranty within Canada and the US to the original customer to be free from missing parts, defects in material, and defects in workmanship for a period of ninety (90) days from the date of receipt by the original purchaser. Sienci Labs Inc. will ensure that the appropriate support is provided to the original customer to restore the LongMill to operational condition or provide a full or partial refund under the sole discretion of the Company.

This warranty does not cover damage due to improper use or assembly, lack of maintenance, normal wear and tear, or modifications to the LongMill which are not produced or authorized by the Company. Consumables such as cutting tools and sample or stock materials which may have come with your LongMill are not included in this warranty.

This warranty will become void if the operator does not follow the Safety Warnings and Guidelines, uses the Product for illegal purposes, intentionally causes damage to the Product, or transfers the Product to another owner.

The original customer must contact Sienci Labs Inc. within ninety (90) days of receiving their order to make a warranty claim to be eligible for warranty service. Proof of purchase, tracking number, email address, or other material will be used to confirm the original purchasing date and the identity of the original customer. If damage was due to shipping, original packaging materials must be kept in the original received condition. Photos, videos, written descriptions, and other items may be requested to assess and validate a warranty claim.  In the case Sienci Labs Inc. requires the original parts to be returned, the customer is solely responsible for packing all items securely. Damage incurred during return shipping will not be covered by the warranty. A method of payment such as a credit card may be requested by Sienci Labs Inc. to cover shipping costs or damaged items if Products are not eligible for warranty service.

15 reviews for LongMill Benchtop CNC MK2

Based on 15 reviews
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Showing 3 of 15 reviews (4 star). See all 15 reviews
  1. Brandon W. (verified owner)

    Two negatives. (1) Received the machine with missing parts after a long wait time on pre-order. Customer service was quick to resolve the issue and sent the parts express. (2) Assembly was relatively easy thanks to the video and assembly instructions. A thorough review needs to address a couple errors in the parts needed for certain sections of assembly. The eccentric nuts and v-wheel assembly onto the two y-axis is to subjective. Assembly and the tightness of the v-wheels is not repeatable and therefore I lack confidence in their longtime use. I still get a “noise” when rapid traveling along the y-axis even after disassembling the v-wheels and backlash nuts and reassembling. It’s better now, and the machine has made several projects with 3+ hour carves and completed with great accuracy. I hope it holds up. If there is something that I’m missing or seem to misunderstand about the v-wheel / eccentric nut assembly please let me know. All other aspects of the machine are phenomenal. A lot of thought went into the design and the main parts are very stout and robust for sure. I know you can leave the machine to do it’s work but I can’t help standing over it to watch the details as it carves and cuts. I foresee making many more projects and look forward to the company growing and continuing to support the cnc community.

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  2. Christine (verified owner)

    Hubby thought the other touch plate came with the machine-we just purchased and received it now. It took him a bit longer than expected to set up, but he is loving it!

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  3. William Scrote (verified owner)

    I would rate my experience with the Longmill as 5×5 but I still have some issues that I have not gotten worked out to my satisfaction. The first is the Arduino board in the control box. While I have been able to make the thing work for the last couple of weeks it started out being a problem because the Arduino board was malfunctioning. But, with the help of the service department and a couple of e-mails we found a work around the loose Arduino board. The then Square D connection between computer and control box malfunctioned so I replaced that on my own.and now works fine. Setting up the machine took a little more time than what the manual said, but overall set up was no problem. I found the hardest part was getting the machine square and the wasteboard surfaced. But when completed my machine was, according to gsender program only .82 mm out of square when I checked square.

    If I had any advice to give anyone first starting out with a CNC Machine like the Longmill and you had no other CNC experience is to READ THE MANUAL. I read and reread the manual four times. before attempting to put together my machine. Taking my time and understanding the machine and its components was invaluable. DO NOT get in a rush setting up your machine.

    Now having worked Construction for the last 47 years and having a degree in Architecture and Construction management is a plus for me. I know by experience that putting things together correctly is time consuming, but very rewarding.

    I started out thinking I would use this CNC Machine to add a touch of class to the furniture I build. Now I am amazed at the world of possibilities that are available with this machine. Simple flourishes and designs in furniture is just the beginning.

    My hobby shop is in my two car garage in Hawaii. I also park my truck in the garage so space is limited. To help with the space issue all my large tools and machines are on wheels the same goes for my new CNC machine. It also has a tilting bed so it will take up less space. Now I find that with this tilt bed I created a small problem for myself where the CNC Machine is concerned. I found the machine after being stored over night would not be square in the y axis. one side would always slip on me. I soon learned that if I left the machine overnight in the complete end of the Y axis this problem was cured, so I started leaving it is that position overnight. It seems that the x axis gantry, z axis gantry, and the router all weigh more than what the y axis gantries can support when the machine is tilted for extended periods of time. So, if you use my table built that I posted on the website please remember to always store your machine at the bottom end of your tilted bed overnight.

    The Fact that it took Ninety days to get my new machine turned out to be a blessing in disguise. I wisely spent my time reading the manual, going on “You Tube” and watching many, many online tutorials on how to use the machine. I would Like to thank Mark Lindsay, and Garrett Fromme for their invaluable lessons they posted on “You Tube”. I would also like to thank the people of Seinci Labs for their patience with all my questions.

    In conclusion, being a new CNC user and using Vectric Vcarve pro with the gsender program developed by Seinci Labs has proven to be the right choice for my needs. I will definitely recommend the Longmill MK2 to anyone who asks me, with the qualifier that I have no other experience with any other machines.

    Mahalo, William Scrote
    Maui, Hawai’i

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