Go to main site 3dtek.xyz

Heavy Mill User Feedback

Hi There

Looking to purchase the heavy mill. I’ve been in touch with Ben who seems a genuine guy that knows his stuff.

Without a warrantee though, it’s more than a little risky.

I was wondering if anyone has purchased the heavy mill and has it up and running successfully. Would you mind providing some feedback please?


Hi Marko,
Ben is a real guy and the Heavy Mill is a real machine. I got one at the end of last year, and am quite happy with the quality of the parts and how well it works.

It’s not the easiest thing to assemble, but if you know your way round a soldering iron and have a fair idea of what you’re trying to do you’ll get there in the end.

On top of the machine cost and build, i spent maybe another $700 building a table, and getting the connectors and wiring the way i like it. It’s not been strictly necessary, i had it operating on the floor, but i wanted to have it neat and clean.

Another heads up - if you’ve never run a machine like this before, expect to spend spent a lot of time tweaking software and trying to learn the CAM side of gcode prep.


Hi Tim Tim:
Getting to the last part of my 1.5 X 1.5 mm heavy Mill in Brisbane, Do you have photos of the electrics that you set up. This is the last thing to complete before testing and using the CNC. I am in Brisbane.


I built a timber table for my Heavy Mill, and put a panel up between the back legs for the electrics.

New photo by Tim Swavley
From right to left is the VFD (PI8100) for the 1.5kW spindle, then the 12v transformer and CNC shield.

New photo by Tim Swavley

I opted to run each terminal set on the 12v bus separately, and each is fused on the positive side, then a sub master switch for each ‘circuit’. There’s one circuit for the CNC shield and cooling fans, and one for the spindle coolant pump. I’m in Townsville (hot) so I’ve wired up the third as spare for additional cooling fans if needed, or I also want to put in a second Arduino with some temperature sensors and warning/indicator lights on a control panel in case the coolant pump fails.

The power feed to the spindle coolant pump will go via the VFD to turn the pump on when the spindle turns on (not yet wired - I just got some pointers from Ben, and will post about that when it’s done).

On the far left in the second pic I’ve mounted some 5v actuated relays. I’ve not wired these yet, but the idea is for them to be linked to the coolant pin on the CNC shield so the spray pump and dust extraction can be turned on/off via Gcode. There will be bypass switches for both of these on my control panel.

The grey cable coiled up is a length of 8 core data cable i purchased locally. It will carry the e-stop, hold, resume and abort pins to relevant switches on control panel. Not finished this one yet.

The 2 12v cooling fans are sitting just above the CNC shield.

I decided to use the terminal strips to connect the cables. They’re quick and easy. the top two are for the the steppers and 12v, and two lower ones are for the limit switches and other control pins.

New photo by Tim Swavley

For the 240v I got an appliance inlet and a few main switches from a local wholesaler and had it all wired up by a sparky. The left switch is the master, the other two are for the VFD and 12v transformer, again on seperate ‘circuits’. This was pretty expensive, but looks pro and is neat.

The whole lot sits behind a perspex sheet to keep little fingers out.


Hi TimTim

Thanks for your comments. It is good to know that the machine is working well for you. This does seem one of the best options out there for a home shop.

I hope you don’t mind a few questions please -

Are you getting clean curved cuts with the machine in wood, or can you see the stepping of the motors?

Also, which electronics package did you go for?

Lastly, how is the accuracy/ tolerances?

Thanks for responding to the post.


Thanks for you info and photos, I have the 2.2 spindle and all is alive and now I have to set up the machine homing and spindle control, I have set a separate water pump that turns whenever I start the spindle. This is through a water chiller that was for the Laser machine. Will post photos soon.

I had similar questions before I got my Heavy Mill.

Clean curves - Yep, curves come up really nicely

Electronics - i was already familiar with Arduino, so i went for the CNC shield. Can’t really give you an explanation of benefits or otherwise of the the other options sorry.

Accuracy/tolerances - i guess it comes down to how well you setup your machine. I calibrated my step/mm setting using a set of vernier calipers. This worked ok, but it relies on your calipers being parallel to the movement axis. I checked the setup with a dial gauge, and found it to be repeatable to approx 0.02 mm. Having said that, you will also need to align and square everything up yourself. at present my X axis is about 1mm higher above the table at one end than the other, meaning the cut gets shallower to one side. Shouldn’t be to difficult to fix, but having to do setup like that yourself is one of the reasons why you can get a heavy mill for $5000, and the next closest commercial machine is >$15,000

Thanks Tim Tim. This is good info.

I have a solid knowledge of assembly and how things go together but no electronics savvy. I guess this will be the main learning curve. I plan a visit to Ben’s shop anyhow to get my head around things.

Hi Tim Tim/Bill

Do I need 3 phase power for the heavy mill, or will the standard 240V of any domestic property do please?

You won’t need 3 phase but by the time you add a 2.2KW spindle and 4 stepper motors, you may close to the 10A limit a normal house circuit provides. At worst, a dedicated 15A connection could be required but I doubt that would be necessary.

Geoffs correct, 3 phase not needed.

I went with the 1.5kW spindle, and the power supply for the steppers is only 360W, so with this setup i’m pulling just less than 2kW. Running the vacuum/dust extraction (not included with the Heavy Mill) will put it over the 10A if they’re all on the one circuit.

Sorry I have not posted photos yet, I run two line to the shed. Both through a safety circuit board. The CNC, water pump & Vacum cleaner (operates dust extractor system) from one line and the computer and control box from another line. This leaves one set of double plugs for other systems. Have not had an issue yet. Bill

Would I be able to visit your place in Brisbane to see a Heavy Mill. Please text answer to 0426699213