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LongMill Benchtop CNC MK2

(176 customer reviews)




Due to high demand, LongMills are expected to ship within 5-6 weeks from the time of 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? Try our step-by-step LongMill MK2 Configurator!

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

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.

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 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.

176 reviews for LongMill Benchtop CNC MK2

Based on 176 reviews
Showing 20 of 176 reviews (4 star). See all 176 reviews
  1. Geoffery Prouse (verified owner)

    Newbie…. So still very excited about it. Created my first project last week. Gonna work on a new project tonight. Lots to learn but very easy so far to learn.

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  2. Jerry Johnson (verified owner)

    Sorry it took so long to reply Chris, I purchased the LongMill 48 x 30 for a Christmas gift. I started assembling it the next day and with the help of your videos was able to complete the assembly quickly. I was having trouble with the x axis lead screw jamming. I kept trying to tune it to no avail. I must say I was getting frustrated, but I kept at it. When I adjusted it to be more square I finally was able to get it to work properly. Your resources area was a great help. I also purchased the Auto zero touch plate. It worked great the first time but then stopped working. Again the resources area on your website helped me again. I tested the continuity of the wiring and was able to find the problem. The ground wire at the magnet was not making contact. I removed the screw and slightly bent the connection ring, reassembled it and I was in business. I made a spoilboard today and the LongMill preformed wonderfully. Thank you so much l’m loving it. Jerry

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  3. Jon Z. (verified owner)

    I feel the price of the machine is very good considering what it can do. Not sure you can find another machine at this price with this quality.

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  4. Marcus Pedroza (verified owner)

    Overall great machine, I have 0 experience with CNC. A few areas I think could be improved upon. Putting together was not terrible, maybe 4 hours with stops and starts. Only a few places where instructions/pictures did not show what I needed. I did like that they sent plenty of spare parts! Would be nice to have information on how to set up limit switches, a short run through on a project from start to finish would be nice, and how to set up vcarve pro with your machine. Also videos on how to setup gsender would be helpful. I am running with the factory settings, but would be nice to know the bells and whistles. I figured most issues out on my own, with the help of YouTube, but as a new user it would be helpful if the information were there from start to finish. Some basics on spoil boards and holding materials would be appreciated.

    Overall customer support has been amazing, very quick response, and very helpful. One thing I would like to see is a way to tram the z axis. When making my spoil board it is slightly off. Not easy to “shim” the router, since the housing is round. All the engineering that goes into this seems like an adjustable mount would not be hard to add. Still learning but glad I purchased. I have been making signs and the learning curve is shortening. One thing I will say is it is apparent I need a planer! If the material is not perfectly flat the router with show defects in height.

    Signs are getting better as knowledge with vcarve is getting better. There are some great teachers on YouTube that walk step by step.

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  5. Timothy Williams (verified owner)

    Needs more router support than just one clamp. Needs easier tramming.

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  6. Kendal Huestis (verified owner)

    I love it, had some start up issues (great customer service and still have a worm gear that isn’t 100% straight( not reported) but it is amazing tool. Would buy it again if needed.

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  7. Anonymous (verified owner)

    Assembly was very easy, pictures in the guide were extremely helpful. I haven’t got the CNC part producing anything just yet, I’ve been focussing on the laserbeam for the moment. I’ve been commissioned to create a donor wall for our community pool made of laser etched tiles. The laser beam is so efficient that etching one tile takes less time than setting up the next design in lightburn!

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  8. James Baker (verified owner)

    I paid $1,650 for my machine. I’m satisfied that I have good value at that price. The machine is very rigid and accurate.

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  9. David ORourke (verified owner)

    Had tough time squaring. Still not sure it’s OK. X Axis extrusion was damaged on 1 end. Threaded screw hole was still intact – Got Lucky . X axis has a point where sound changes and lead screw wobbles a bit more. Still working on getting things setup. (Dust collection then surfacing) Harder than I expected. Thanks, David

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  10. Georges P. (verified owner)

    I have not use the CNC much yet since I’ve been working but the projects I have been able to run of it came out within specification of the CAD designs. It is very accurate and very powerful as well. For the price, it is a good machine. Assembly was straightforward. The only problem I have encounter is with the limit switches. I seems to get errors running codes when the switches are on. So far, I have turn them off. Hopefully the software gets better and the switches works without faults.

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  11. Patrick D. (verified owner)

    Value for price is great. Wish there were a way to have the controller toggle the router on and off.

    Have had the bolts come loose on the carriage clamp that rides the ballscrew. The loose bolt marred the aluminum as the machine traveled with it pinned between the clamp and the x-axis. Created a burr that had to be sanded down to repair. Not sure why they backed out.

    Stepper motors get ungodly hot even when theyre not operating much. Raises concerns for end of life on parts coming sooner than I had hoped for.

    Drag chain doesnt like to stay oriented perpendicular. It gets pushed diagonally and doesnt sit on top of the x-axis. Maybe the 3d printed brackets to affix to the machine could be beefier so you can really torque down on it to prevent the chain pivoting.

    3d printed saftey covers for the ballscrew nuts were included for the smaller nuts, but not for the larger 48×30 nut.

    Wish dust boot also included a sliding rail to adjust and fix it at different heights.

    Auto zero doesnt work with really tiny bits like 2mm in Gsender. When it goes to touch the leftmost x bound, it approaches but never touches it and then throws an error. (This one is likely user error).

    Gsender crashes if you try to load to large of a gcode file.

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  12. Jeffrey Maitland (verified owner)

    The assembly of the machine was a bit confusing at times. Most of the video’s available are for the small 30×30 and not many for the 30×48 which has some differences. There in no updated video on installing the inductive sensors.

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  13. Robert Blondeau (verified owner)

    Everything about the long mill has been great now that the setup is complete. I initially had trouble with one of the y axis motors stalling out but I think that’s probably due to my surface not being flat enough. A bit of adjusting later and all is good.

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  14. Dave Appel (verified owner)

    I enjoyed assembling and learning how the Longmill runs. Seems like sturdy materials. A couple of suggestions. First, I was disappointed that instructions to mount the optional limit switches were not included until the machine was fully assembled and fastened to the table. It would have been easier if they had been included as an option earlier in the assembly instructions. Second, I have been reading a lot of the online discussions about parts wearing ou in 6 months or so. Why not include an extra set of wheels and nuts with the original kits so that it feels like we are really getting our money’s worth.

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  15. 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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  16. 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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  17. 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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  18. 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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  19. 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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  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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