So you haven’t bitten the bullet yet, but you’re curious about the AltMill?
We got you – check out our FAQ below for prospective customers, addressing questions such as backward compatibility to the LongMill, spindle sourcing, work area dimensions, and add-ons.
What are the power requirements for the AltMill?
Please check your breaker ratings and wiring to see if your home or shop is compatible with these loads. We recommend allocating two 15A circuits, one for the spindle and dust collection system, the other for the controller and computer.
If you live in a country with 220V/240V power, you must use a transformer to convert to 110V/120V. It needs a rating above 500W for solely running the machine, or 2000W for running both the machine and spindle. You may wish to use the transformer only for the machine, then purchase a third-party spindle available for 220V.
What motors are on the AltMill, and can they be adapted to the LongMill MK2?
The Altmill uses closed-loop steppers with external motor drivers plugged into the SLB-EXT controller, whereas, the LongMill MK2 uses open-loop steppers with integrated drivers directly soldered on the SLB controller. Because of these major differences, you would need to purchase the SLB-EXT controller in addition to the closed-loop steppers (plus 8mm to 8mm and 6.35mm to 8mm couplers) to make this modification.
If you are looking to modify, please be aware that our customer support team may not be able to provide troubleshooting and best practices on this matter. We have not tested the LongMill with this specific modification. However, feel free to send us progress updates!
What is the accuracy of the AltMill?
The accuracy is +/- 0.05mm to 0.1mm.
I would like to source my own spindle, what should I be aware of?
Our spindle is rated at 1.5KW, 110V which can run off North American household outlets. We recommend keeping the spindle power between 1.5-3.5KW. If you reach 2.2KW or above, you will need to install extra 220VAC wiring to support this. Furthermore, ensure that the spindle body is 80mm or smaller in diameter so that it could be mounted onto the AltMill as-is or with your own shimming. The AltMill comes with an 80mm spindle mount, whether you purchase the Spindle Kit or not. You can check out this page for more guidance on sourcing your own spindle.
Please be aware that our customer support team cannot provide troubleshooting on other companies’ spindles and VFDs.
Are the SLB and SLB-EXT control boards interchangeable?
No. The SLB is for the LongMill and the SLB-EXT is for the AltMill.
The SLB-EXT comes with specialized electronics and programming to allow for the use of a 48V power supply and external driver support, suited to the AltMill.
Which add-ons are compatible with the AltMill?
- AutoZero Touch Plate
- Standard Touch Plate
- Vortex Rotary Axis*
- LaserBeam Laser System*
- T-Track Set**
- Threaded Insert Packs
*Full support for the Vortex Rotary Axis and LaserBeam Laser System will be coming soon.
**Currently our t-track sets are sized for the LongMill MK2 depth. If you wish to use the tracks for your AltMill, please order extra tracks to cut to length to extend the full depth of the AltMill. T-track installation can be found here.
What computer should I get?
Many of our users have successfully designed, created g-code and operated their machine with mini PCs and laptops. Or they have a two-computer setup, where they dedicate a spare, inexpensive computer to run their machine in their shop, and use their higher performance, internet-connected home computer for design and CAM. G-code can be transferred between computers just like any other file, such as via USB stick. See here for detailed system requirements.
Has my AltMill shipped?
We will send out an email when your machine has shipped from our facility. If you haven’t received the email and the expected lead time has passed, then feel free to contact us for an update.
The shipping and delivery times for the AltMill may vary depending on current demand, availability of parts, and our production rate. You can find up-to-date estimates posted every week and a queue on our Order Status Page. Orders, once they are ready, can be picked up directly from our office during working hours (typically Monday to Friday, 9:30AM to 4PM), or are shipped by courier. Shipping times may vary depending on your region, but most are delivered within 1 week.
Can the AltMill 4×4 fit a 4’x8’ sheet?
Yes! The work area of the AltMill is approximately 49”x49”. You can feed the sheet from behind so that the machine can cut a portion of it at a time.
What is the size difference between the AltMill 2×4 and 4×4?
The 2×4 has a working area of 25″ by 49″ and the 4×4 has a working area of 49″ by 49″. Both machines have a maximum Z-height of 5.5″ for allowing stock material.
Will there be a bundle deal for the AltMill, like the MK2.5 Beginners Kit?
Currently (as of February 2025) there are no plans for a bundle deal.
Will there be a way to upgrade from a 2×4 to a 4×4?
We intend to release a size upgrade kit a few months after the release of the AltMill 2×4, so we recommend picking the size you’re comfortable with, up front, for now.
Do you have a trade-in program to upgrade from the LongMill to AltMill?
No, currently we do not have any system that could allow you to trade-in one machine for the other, and do not intend to in the future.