Input on DIY budget cnc machine

[Noppishen]

I am in the planning stage of building a machine on a student budget.
Before starting building I'd like some input from people more experienced than me, this will be my first machine.

Build area is approximately 200*400*225mm.
I'd want it to be as capable as possible, but I will mostly cut aluminium or softer materials.

The machine would probably be made of mostly 20mm aluminium, it would be really difficult for me to work on steel, I also do not have the ability to weld.

I am planning to use a 2.2kw china spindle and HGR20 linear rails, used name brand ones, or generic new ones.

Motors would be 3nm Nema 23 stepper motors driving ball screws.

Id like to keep as many doors open as possible, I won't use flood cooling to start, but would want the ability to add it later. Will start with mist cooling.

The rails would be covered by bellows, they aren't modeled in the CAD.

The stepper motor mounts are not modeled yet either.

To increase the mass of the machine the steel beams that make the main chassis could be filled with concrete or something else.

Any input is greatly appreciated!

[JAZZCNC]

Why re-invent the wheel.?

What you have shown is just a Milling machine so buy a Manual milling machine and convert it to CNC.

It will be cheaper, quicker, and if you have no welding skills or equipment to Mill parts, etc then more accurate.

[Noppishen]

Thank you for your input.
I have some reasons for that,
A milling machine is simply too big and heavy for starters, I live in an apartment with my parents.
I might have the main frame welded for me.
I also only cannot use 3-phase electricity.

[AndyUK]

Thank you for your input.
I have some reasons for that,
A milling machine is simply too big and heavy for starters, I live in an apartment with my parents.
I might have the main frame welded for me.
I also only cannot use 3-phase electricity.


I suspect Jazz was talking about something the size of a Sieg X3, rather than a full-on vertical mill.

A Seig X3 would take a single phase input, be as noisy and big as your current plan, maybe slightly heavier but its to your advantage (and its still moveable).

You could buy a manual one and do a CNC conversion if that's the bit that interests you?

[Noppishen]

I suspect Jazz was talking about something the size of a Sieg X3, rather than a full-on vertical mill.

A Seig X3 would take a single phase input, be as noisy and big as your current plan, maybe slightly heavier but its to your advantage (and its still moveable).

You could buy a manual one and do a CNC conversion if that's the bit that interests you?

I want something stiffer than that, I have heard online that mini mills are questionable. The table is also a bit smaller. I'd have to change from the chuck too.

If fusion 360 is to be believed, my current design would weigh 256kg, with the option of filling the main frame.
I might also have found a way to weld the main beams to make the main frame.

Some of the appeal would be the clear upgrade path, flood cooling, Mechatron spindle, Hiwin linear rails etc. I really like that it is designed to fit into a tight housing.
As long as the main frame is sturdy enough I believe I can upgrade it to be as accurate as possible later on.

I am pretty set on building it myself, but you guys can probably spot if I have made any large mistakes in my design, or if there is some easy way to improve performance.

[JAZZCNC]

I suspect Jazz was talking about something the size of a Sieg X3, rather than a full-on vertical mill.

A Seig X3 would take a single phase input, be as noisy and big as your current plan, maybe slightly heavier but its to your advantage (and its still moveable).

You could buy a manual one and do a CNC conversion if that's the bit that interests you?

Yes Andy something like that.

To the OP, I understand the desire to DIY build and I'm the last person to put anyone off DIY building but in your case with the design you show then it would be a mistake to build as you are not making it any better than a standard off the shelf Mill, infact it will be quite a lot weaker.
To do this correctly and gain any advantage over a standard Mill will require much heavier tubes and bracing of the frame along with equipment like milling machine to help you achieve accuracy. The welding alone of thick tubes will require Higher power welders than your average DIY build will have access to and bolting together alone just doesn't work very well.

If you don't have equipment to help you do this then your just going to waste money and be very disapointed with the end result.

I strongly advise you to Re-think this and look at converting a manual mill like the Sieg X3 etc.

[Colin Barron]

Thank you for your input.
I have some reasons for that,
A milling machine is simply too big and heavy for starters, I live in an apartment with my parents.
I might have the main frame welded for me.
I also only cannot use 3-phase electricity.

The first consideration is, at your estimate of 250Kg machine weight is the apartment floor concrete? If you are going to add concrete weight, how will you remove the machine at a later date? As others have suggested, buy an old machine and rebuild it using new electronics because machining and labour are very expensive. Also the time and effort to build from scratch would maybe be better spent learning how to use software. Also a modified machine has some resale value.