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AltMill 4×4
AltMill 4×4 Legal
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AltMill 4×4
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1-Year Warranty
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AltMill MK2 4×4

(289 customer reviews)

$3,160.00

The AltMill is the pinnacle of hobby CNCing, bringing industrial-level precision to a price point and ecosystem for both beginners and advanced users. The AltMill MK2 4×4 is your go-to CNC when time, performance and precision are crucial for production-level reliability.

The AltMill MK2 4×4 comes with a standard 80mm spindle mount only. It does not come with a spindle, which must be purchased separately.

Ontario. Canada Customers: Starting April 29th, we’ll be pausing sales for all sizes of AltMill. Please read further on specific plans for each machine – ESA Compliance.

 

Lead Time: 2 weeks

    Description

    Highlights:

    • Production level cutting speeds (approx. 600 inches/minute)
    • Closed loop motor system on all three axis to auto-correct positioning and auto-stop when necessary (reliable for production style work)
    • Requires little maintenance during project production
    • Advanced, production-style features including Y-axis auto-squaring; limit switches by default; and tram adjustment capabilities
    • Cuts materials ranging from hardwoods to plastics, foams, composites, aluminum – even steel
    • Support for 80mm spindles and routers
    • 49″ x 49″ working area with a max Z-height of 5.5″
    • Footprint of 59″ wide and 62″ deep

    Lead times
    This product has a potentially long waitlist, relative to demand and seasonality. For more info on expected shipping and delivery times, please see our Order Status page.

    Additional information

    Weight 76 lbs
    Dimensions 38 × 11 × 12 in
    Include Spindle and Dust Shoe Kit

    Include Spindle and Dust Shoe Kit, Machine Only
    origin-criterion

    C
    Lead time

    2 weeks

    What's Included

    Included with your AltMill MK2 4×4

    • SLB-EXT controller and emergency stop
    • 48 Volt Power Supply
    • Partially pre-assembled rigid frame
    • Inductive sensors for homing
    • Sturdy metal legs with the ability to add 4ft wide shelving underneath

    ***Not included with your AltMill MK2 4×4***
    Check out our recommended products tabs for an ideal set up, but note the following ARE NOT included with your order:

    • Computer or laptop
    • Spindle
    • End mills or bits
    • T-tracks
    • Waste board (e.g. MDF 2ft x 4ft sheet)
    • Set of metric Allen keys, standard bits or drill for assembly

    ***Some photos may contain items for illustrative purposes, such as spindles, caster wheels, t-tracks, or additional shelving. There may also be cosmetic differences between the machine in the photo and the production version of the AltMill.

    Specifications

    Specifications

    • Rigid frame and linear motion design using HGR15 linear guides and ball screws on all axes mounted to a custom-designed, machined aluminum extrusion
    • Closed loop stepper motors for over 600IPM
    • Support for 80mm spindles and routers
    • 49″ by 49″ working area with a max Z-height of 5.5″
    • Inductive sensors for homing included
    • Sturdy metal legs with the ability to add 4ft wide shelving underneath
    • Footprint of 59″ wide and 62″ deep

    Must Have Add-on: 1.5kW, 2.kW Spindle or 2.2kW ATC Spindle

    Unlock the full potential of your AltMill with a 1.5W or 2.2KW ER Spindle and Dust Shoe Kit, or, an Automatic Tool Changer Spindle Kit

    Each 1.5KW ER20 Spindle & Dust Shoe Kit comes with:

    • 80mm Dust Shoe
    • ER20, 80mm, 1.5KW 110V Air-Cooled Spindle
    • 110V, 1.5KW, 3-Phase VFD
    • AC power cable and 5m spindle power cable
    • ER20 1/8″, 1/4″, 3/8″and 1/2″ collets (one of each)
    • Data cable to connect to the AltMill/SLB-EXT controller for remote speed control

    Each 2.2KW ER20 Spindle & Dust Shoe Kit will come with:

    • 80mm Dust Shoe
    • ER20, 80mm, 2.2KW 220V Air-Cooled Spindle
    • 220V input, 2.2KW, 3-Phase output VFD
    • NEMA 6-15P AC power cable and 5m spindle power cable
    • ER20 1/8″, 1/4″, 3/8″and 1/2″ collets (one of each)

    Each ATC Spindle Kit comes with:

    • 2.2kW ATC Spindle
    • ATC Spindle Mount
    • Enclosed 2.2kW VFD and Mount Adapter
    • Clear Cut Dust Shoe
    • Tool Length Sensor
    • ATC Expansion Board for an SLB-EXT Controller
    • 2.2kW VFD NEMA 6-15P Power Cord
    • 10m Length 8mm Air Line Tubing
    • Male ¼” NPT to 8mm Air Line Push Fitting
    • ER20 Collet Wrench

    **Each ATC Spindle Kit comes with a variety of tool holders, collets or racks (or no rack.) Read for more details.

    Recommended Add-ons & Accessories

    FAQs

    Choosing an AltMill vs a LongMill

    Payment
    Full Payment is required at time of purchase to get your order into the Queue. We ship on a first-come, first-served basis. If you choose local pick-up, you are subjected to the queue order and cannot get your machine quicker.

    Power Requirements
    AltMill with the 1.5kW spindle. We recommend allocating 2x 15A, 110V/120V circuits — one for the spindle, the other for the machine and a computer.

    • The AltMill consumes 500W and runs off a 48V 10A power supply, 110-120 volt circuit
    • The 1.5KW Spindle Kit consumes 1500W at max load, 110-120 volt circuit

    AltMill with the 2.2kW spindle. We recommend allocating 1x 15A, 110V/120V & 1x 20A, 220/240 Circuit — one for the spindle, the other for the machine and a computer.

    • The AltMill consumes 500W and runs off a 48V 10A power supply, 110-120 volt circuit
    • The 2.2KW Spindle Kit consumes 2000W at max load, 220-240 volt circuit

    If you live in a country with 220V/240V power you must use a transformer to convert to 110V/120V.

    • To solely run the machine, you need a rating above 500W
    • To run the machine and a 1.5kW spindle, you need a rating of 2000W

    AltMill Power Supply Specifications: Input: 100-130 VAC 50/60 Hz, 7-54 Amps, Output: 48 VDC 10 Amps, 480 Watts

    3rd Party Spindles – I would like to source my own spindle, what should I be aware of?

    • For spindles 2.2KW or above, you will need to install extra 220VAC wiring
    • The AltMill comes with an 80mm spindle mount, we do not have larger diameter mounts at the moment
    • The VFDs that may work with our controller are: Huanyang v1, Huanyang P2A, Yalang YL620, H-100, and GS20, however they are not plug-and-play — read this article for further information

    Warranty

    The AltMill has a 1-year 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 AltMill 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 accept returns for AltMills that have already shipped.

    General Warranty and Limits of Service:

    Effective August 1, 2026:

    Throughout this policy the words “we”, “us” and “our”, or “Sienci Labs” will be used to refer to Sienci Labs Inc. herein and “AltMill” or “machine” will refer to Sienci Labs’ Sienci AltMill. 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 AltMill (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 three-hundred-sixty-five (365) 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 AltMill 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 AltMill 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 AltMill 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 three-hundred-sixty-five (365) 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.

    Instructions & Assembly

     

    Videos

    Shipping

    289 reviews for AltMill MK2 4×4

    4.7
    Based on 289 reviews
    5 star
    84
    		84%
    4 star
    10
    		10%
    3 star
    2
    		2%
    2 star
    1
    		1%
    1 star
    1
    		1%

    1. James Goodall (verified owner) –

      Nice machine. Wanting a bit more Z height (gantry arms length). 1″ would help but 2″-3″ better. I see your custom Altmill “tapping mill” has taller gantry arms I believe. Could they be purchased if so?

      (0) (0)

    2. James E. (verified owner) –

      Machine is nothing short of amazing!!

      (0) (0)

    3. Bradley Bustard (verified owner) –

      Cord management could be better

      (0) (0)

    4. Joy T Pearce Jr (verified owner) –

      I really like this CNC it does great. There are a few things that need to be addressed in the set up that was uncleared like the length of the wastboard for the automatic tool changer and where to rout the zed cable at the tool changer you can’t run it up the drag chain it is to short to do so etc.

      (0) (0)

    5. Brian L. (verified owner) –

      Very well engineered and the open source makes customization very easy. A fun project with endless potential for its class.

      (0) (0)

    6. RONALD VANTINE (verified owner) –

      Placed order for machine in August. UPS only delivered one of the three boxes. Your customer service won’t replace or refund the order since UPS won’t admit they lost the packages. I realize it’s not Scienci’s fault but This whole experience has been horrible. Maybe someday I will get the parts to build my Altmill but I’m losing faith in the process.

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    7. STEVEN LAMBERT (verified owner) –

      Love the cnc and 2.2kw spindle , I will say , there is a spot of oxidation on one of the cross members that I wasn’t pleased about but I put it at the back of the machine so I don’t have to look at it other then that , no problems because there is always solutions;)

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    8. Gordon Barcomb (verified owner) –

      Really GREAT! as a 100% beginner with some specific plans, I was a little worried that it was too much machine, but several people assured me it was not. They we RIGHT! Using it to make parts already. It’s a small adjunct to our regular business, but it’s already paid back 1/2 the investment in 3 months.

      (0) (0)

    9. Luke M. (verified owner) –

      Great machine. Solidly engineered and well supported.

      (0) (0)

    10. Timothy Bryan (verified owner) –

      It is hard to imagine what could be easier to assemble. Every package of screws was labeled and the instructions referred to them by the same name and size. Everything went together exactly as described in the documentation. This is my second CNC and very quickly became my favorite. It is rigid, fast, and efficient. I plan to build a shelf under the machine and include some drawers to organize my bits and other accessories. I do wish Sienci labs would sell a kit that would allow you to build this with kit parts.

      (0) (0)

    11. Anonymous (verified owner) –

      NICELY DONE

      (0) (0)

    12. Robert Brisson (verified owner) –

      Easy assembly, well packaged.

      (0) (0)

    13. Jay R. (verified owner) –

      Machine is rock solid. Very well built, you can tell the team took a lot of time to make sure everything was perfect. Speed of cuts is incredible, and this is as close to plug and play (if you have experience with cncs) as possible. Only piece of advice is to make sure you are reading through the instructions and then looking at the latest videos for assembly instructions. There were tiny differences based on when we got the product that make assembly different and if you don’t read/ watch both in advance you may not understand how the newer pieces or steps work and do the wrong thing accidentally based on old methods of assembly. Normally this would warrant a lower rating but I’m telling you, the machine is just that good that it was worth the effort. Contact the team if you need help, they are eager to help.

      (0) (0)

    14. Peter W. (verified owner) –

      Went together without a glitch, no missing parts and relatively easy to manage by myself.. top marks… a coupel of updates didn’t make it into the instructional videos on youtube but no issues that were huge, or that wasn’t self induced 🙂

      (0) (0)

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