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LongMill Benchtop CNC MK2

(341 customer reviews)




LongMills are expected to ship within 1-3 days from the time of order. Each machine is made to order.

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? Check out the Beginners Kit.

Shipping is calculated at checkout.



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.

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
  • 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

Weight60 lbs
Dimensions8 × 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.

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:

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.

341 reviews for LongMill Benchtop CNC MK2

  1. Paul W. (verified owner)

    Love my Longmill. Putting my machine together was very intuitive. Using my Longmill has been the best part. Seeing a design go from thought to reality is a thrill, instant gratification. It is a steep learning curve for the software, VCarve and gSender, but worth it. I haven’t had to call customer service, but I hear it is top notch.

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  2. Bradley Spears (verified owner)

    the only thing i could not find the set screws for the backlash pieces

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  3. Brandon Setzer (verified owner)

    I figured it out I hade to buy V crave I can’t use the free Version

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  4. Ed Clarke (verified owner)

    Love my machine now that its up and running. Its not as easy as you say it is to setup and use. I had to walk away from it a few times. You advertise no experience necessary. It may be true but some knowledge would be helpful. Don’t get me wrong its a great tool and it fun and there is lots to learn. Seeing what people do amazes me and I think one day I will do something like that. Its a learning curve that I’m willing to learn.

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  5. Darryl Q. (verified owner)

    I ventured into cnc as another tool added to my woodworking hobby / side passion. I had no prior experience with cnc and was a little nervous about the software involved. Luckily there are numerous YouTube videos that help tremendously.
    The assembly wasn’t as long as I thought it would be, thanks to the well explained directions and assembly pictures with each section. I have not yet had to deal with customer service directly but love the online community support from both staff and fellow cnc’ers. I have read other post from Longmill owners that customer service is excellent.
    I am presently working on 2D stuff, mostly signs and v carving. Will soon be advancing into the 3D projects hopefully. I also ordered the Laser attachment from Sienci. Looking forward to that also.
    So far it’s been a positive experience and I look forward to making new projects, as I continue to grow and learn.
    Thanks Sienci
    Darryl Q

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  6. Peter v. (verified owner)

    I have had my Mk2 sitting in the box for the last month, and have not had the time to assemble it yet. I work for myself and by myself and have just been too busy to assemble my LongMill. I have completed the room where I will set up the Mk2 this last weekend and am now in the process of building the table. I look forward in anticipation to the day when I can finally cut something on my CNC. I am continually watching YouTube and learning the software with what little time I have available, but look forward to taking the first step, eventually.

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  7. Gino F. (verified owner)

    Followed the directions and it was a breeze to put together, so far it has done what I have asked of it. Pretty pleased so far, once I become more efficient in my job set up, I’m sure it will be even better. Have done many “practice “ pieces in MDF, and am now starting to use lumber. Think I will upgrade my touch sensor, tired of changing from tapered or vbit to put in a straight bit to touch off with. Thanks for making a very good & affordable product.

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  8. Robert McNanley (verified owner)

    The install went very well – great Docs

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  9. Ken Gulley (verified owner)

    Packaging was top shelf, great job. At the time, I seem to recall it not being real obvious things were packed in the rails, but with the videos out now, that should be better. Assembly via the documentation went well, I did have to tap the lower left bolt hole in the X-axis rail. This wasn’t a big deal to me, as I have a well stocked shop (tool-wise). Sometimes I would have benefitted from pictures/diagrams being zoomed out, to more easily determine location & orientation. Still, all in all, assembly was a pleasant experience.
    Since then, I’ve had continuous problems with software and connectivity. Bad enough that you did send me a replacement Arduino, but I’m still working through it. The issues are more like gremlins, in that they are a bit random and hard to pinpoint as far as troubleshooting goes. Unfortunately, the disconnecting issue has left me with little confidence, so I’ve been relegated to simple (short) projects and “dry runs” of more challenging ones.
    Non-software wise, I am finding the v-wheels a challenge to keep adjusted, often times making it seem the x-axis is “cocked”: the upper front (UF) wheel will be too tight, yet the LF wheel is too loose, while the rear wheels are the opposite. I’ve adjusted them so many times I’m afraid I’ll wear out the eccentric nuts. But, it generally seems to move along the rails okay.
    The overall quality and and strength of the machine appears far beyond the price point, certainly have no complaints there. As a newbie, I didn’t notice the feed rate had changed from MM to inches and ran a 1/4″ end mill in pine at 1500 in/min at 1/4″ DOC; will little experience, I just thought, “wow that seems to be fast”, but wasn’t sure, because the machine was tearing thru it with no strain. I did quickly decide something was wrong, but still, I was amazed at how it just plowed through like it was just another day of cuttin’.
    Not sure if this is way longer than you were looking for, but thought more is better in this case.
    As another side note, your decision to include “extra” parts is pure PR genius. In my mind, that alone elevated you to superior vendor status.
    Yes, I’m still having problems, but I look forward to working through them and being another productive and satisfied member of the Sienci family.

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  10. Bob W. (verified owner)

    The setup instructions were really well done and easy to follow. This is a great machine and so fun to use.

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  11. 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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  12. Derek Carriere (verified owner)

    New to cnc’s. Ive ran several projects to date differing in size and complexity and im very pleased to date. So far my only suggestions to Sienci would be to come up with a way to adjust the tram.

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  13. Michael Homann (verified owner)

    Other than my…um screw ups it works great. Very happy.

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  14. James ETubbs (verified owner)

    I love this mk2 had start up issues and a few broken parts form shipping but was all fixed quick and have been working hard at it have told everyone that I know that ask me about it were to go and get them one

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  15. John Steffy (verified owner)

    It would help if you would supply a 5mm T-handle hex wrench in addition to the 5mm, 90 degree hex wrench. I used a T-handle and it made assembly much easier.

    (1) (0)
  16. Stephane C. (verified owner)

    I am loving it, i am getting better at every test i make

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  17. Dave Kinnunen (verified owner)

    The machine is very impressive and great to use I just have a learning curve with the software

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  18. 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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  19. Ryan Jarvis (verified owner)

    This machine does absolutely everything I want perfectly! I’ve used it daily for the month or so that I’ve had it with no issues. The assembly instructions were probably the best I’ve ever seen and I had everything up and running in about 3 hours with no prior CNC knowledge! I can’t suggest the MK2 enough!!

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  20. 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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  21. David Ursino (verified owner)

    Waiting 3 1/2 months was well worth the wait. Solid machine. Runs perfectly. Customer service is excellent too.

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  22. Per Steinar Kotani H. (verified owner)

    So far, everything works fine. Some fine-tuning, and it is flying! For the price, you can get no better.

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  23. Herbert Wallace (verified owner)

    I have 31 years of CNC background in the metal working environment. Extensive manual programming as well as computer assist. I will tell you this wood working CNC is a different animal in that the terminology is different as well as the types of cutters and even the models are different….
    It took me a long time to set up the MK2 just because my shop is not heated and so I was not out in the shop much.. as far as tech support and missing part request that was needed, I was taken care of very quickly. I’m using Carbide Create with G-sender. I really liked the surfacing option inside G-sender. Worked great. That’s as far as I got so far but I’m working on putting a hole in the spoiler board to allow long boards to go down into it so that I can cut box joints on the end that sticks up into the work area.
    Looking forward to proceeding.

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  24. Charles G. (verified owner)

    Very solid machine. An easy build with great instructions. I feel that I know each part of my MK2. Just surfaced my spoil board with the gsender program. It went very well.
    Can’t wait to start making projects.

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  25. Kevin Lockhart (verified owner)

    Your company has been very helpful. You have provided speedy response to any questions I may have had. I recommend your product to anyone looking to purchase a long mill.

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