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LongMill Benchtop CNC MK2.5

(389 customer reviews)




LongMills are expected to ship within 3-4 weeks from the time of order. Each machine is made to order. Please Note: “In Stock” means we can accept orders, but LongMill  Kits are currently unavailable to ship immediately.

The LongMill MK2.5 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? Check out the Beginners Kit.

Shipping is calculated at checkout.



Turn your ideas into a reality with the LongMill Benchtop CNC MK2.5

The LongMill MK2.5 is an improved version of the LongMill MK2, with changes including:

  • The new SuperLongBoard
  • Spring Loaded Anti-Backlash Nuts

…and other minor changes.

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.

We designed the LongMill to be the best hobby CNC router in its class, offering rigidity, and reliability. With large extruded aluminum rails, fully supported Y-axes, 1/4″ steel gantries on all axes, high power NEMA 23 motors, and high precision MG-12 type linear guides on the Z-axis, the LongMill MK2 is the most powerful CNC router in its class at its price point.

This kit comes with:

  • All rails, gantries, fasteners, lead screws, and other hardware parts to make a complete LongMill
  • All electronics, including power supply, controller, drivers, and motors.  Please Note*Power supplies are 110V only, (North America).  If you live in a country with 220V/240V power, our standard LongMill MK2 power adapter must use a transformer with a rating above 300 watts to convert their power to 110V/120V
  • Assembly instructions and resources
  • Excellent lifetime technical support during the life of your ownership

Tools and supplies needed for assembly (not included in the kit) are

    • 3/4″ MDF sheet to act as a working surface
    • An electric drill or screwdriver
    • A laptop or computer
    • A router and end mills (for purchase separate on our store)

For routers, we recommend the Makita RT0700/RT0701. It’s reliable, powerful, 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.

Additional information

Weight 60 lbs
Dimensions 8 × 10 × 41 in


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 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.

Makita RT0701 Router

We recommend using the RT0700/RT0701 Makita trim router with your LongMill (we only sell the 110V version). 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:

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 is primarily designed for cutting wood but is capable of cutting foam, plastic, and soft metals such as aluminum and brass.

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.

389 reviews for LongMill Benchtop CNC MK2.5

  1. Brandon W. (verified owner)

    Only one issue when assembling, the gantry plates weren’t tapped properly had to re-tap. Other than that extremely happy with the machine.

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  2. John H. (verified owner)

    This is my second Longmill and I think it is fantastic. the first one was wonderful for learning how to work with a new tool system, but the Mk 2.5 is rock steady and perfect for the kind of boxes I make and sell.

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  3. Allan G. (verified owner)

    I have been so happy with the strength and reliability of these machines I now have both Mk1 and Mk2 running in my shop side by side complete with laser and vortex still a lot to learn. They have earned there keep a few times over

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  4. Mohsen Torabi (verified owner)

    I have really enjoyed having the my longmill.

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  5. Sean C. (verified owner)

    Initial setup of the machine took longer than I expected. Had to file 2 support tickets and they were very quick to respond. However, putting the machine together helped me learn the mechanics of the machine better which is a real benefit.

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  6. Ryan M. (verified owner)

    Super machine. I have used a few different models and this is by far the best cnc machine I have used. Quick and easy to put together and works better than expected.

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  7. Wally (verified owner)

    I like the machine though I feel the Longmill may not have been the best choice for my application. I’ve had the X Axis stall on me on several occasions during a cut as I think stepper motor is under powered for my application. Recently it stalled during a cut (3/16 compression bit .375 depth,19000 RPM, 75ipm) when it hit a knot in a cedar board. Note: using a PWNCNC 1.5KW spindle & SLB.

    The repeatability and accuracy is satisfactory recently completed project is a chair. This completes the patio/gazebo furniture I began to build last summer. The table and first 3 chairs were built using traditional power & hand tools. With some additional tweaking of the tool paths I expect to be able to offer the chairs for sale.
    I would most definitely recommend the Lonmill for a serious hobbyist to light production type application.

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  8. Evan U. (verified owner)

    The MK2 is very simple to build and operate. I am using G-Sender with Vectric V-Carve and haven’t had software or carve issues. I use a micrometer to set the depth of my material and set the depth of carve. I bought the new zeroing puck and it works well unless I’m using a larger V bit or surfacing bit.

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  9. Bruce Wood SR (verified owner)

    Went together great,got everything lined up and ran a test job working great

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  10. Dennis (verified owner)

    good machine for the price

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  11. David Braden (verified owner)

    My longmill looks like it’s going to be great. Don’t have my spindel yet to try it.

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  12. Anonymous (verified owner)

    Easy to assemble and use!

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  13. Bill V. (verified owner)

    great to assembled

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  14. Scott Noble (verified owner)

    Let me first clarify, my rating could be a 5, it’s only my 2nd entry level CNC machine and although I am very experienced with small scale wood working equipment I’m still naive when it comes to entry level CNC router machines IMO. But…
    solid materials, easily assembled. It’s apparent these guys had some engineering education and drive. Don’t have to be a jet mechanic to assemble, though I am one. It’s talked about even at Sienci Labs as a hobby machine but I have run it steady from day one for at least 2-3 hours per day often more on products I sell.

    I use gSender and create my gcode from Carbide Create with no problems. I tried an Xbox controller but it’s not as smooth as the screen controls on my laptop, don’t know how I could explain that better.

    So I’m honestly shy about what I could say about my the Longmill or gSender for that matter. My “other” CNC is a Shapeoko 3xl. As you might already know you mostly need to use Carbide Motion to run gcode files (from Create). I say mostly because I tried to use gSender to run files from Create and it was really wonky and I didn’t want to troubleshoot why. And still don’t want to know why.

    And so back to my initial review of the Longmill as requested from Sienci Labs. I purchased the Auto Zero gizmo and it is very accurate. I zeroed sooooo many times on my Shapeoko with the paper method and really thought I knew how to be accurate and not purchase a touch plate. I thought I knew better. Yesterday I used the AutoZero with a surfacing bit and it really bared down on the plate. Probably operator error. The rest of the day I used paper but only on that bit. On many zero’ing fuctions it hasn’t failed on any of my end mills. I’ve tried it on several V-bits nervous that it would bear down and hurt the bit but no, it was fine. Soon I’ll be getting back to more V-carves but I’ll make sure there are solid connections with plate and magnet.

    Sorry, I don’t perform 3d carving so I can’t comment on that. No doubt the Longmill would move along nicely with those cut files.

    I did purchase the dust pick up gizmo and installed the bracket, haven’t used the full attachment because I use my 3d printed dust boot I created for my Shapeko and it’s what I need right now for my projects. No doubt it will work when I get back to some sign engraving. It’s very well designed. And no, my 3d printed dust boot for 65mm routers is not available. It’s mine, all mine, my precious!

    If you are window shopping for an entry level machine and ready to “take the leap” then I can say with confidence this young/energetic Canadian shop will meet your needs. I would purchase this machine all over again should my small productions needs increase. Good luck, happy machining.

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