3-Axis precision mini CNC machine

[xzswq21]

Hello
I want to cut and bore small stainless steel, Aluminum, Teflon sheets, for example 8"x8" or 4"x4" sheets, but the CNC machine should be precision (accuracy should be 0.05mm or better)
Do you know such a CNC machine with a reasonable price?

Thanks

[Benta]

I know several such machines, but the main question is: how big is your wallet?

[xzswq21]

I know several such machines, but the main question is: how big is your wallet?

please write your Options, sometimes our wallets are stretched.

[Benta]

Where are you in the world? The offerings differ from region to region, and shipping heavy machines is costly. It's best to go for local offerings.
I don't need your adress or country, but region or just continent would help.

[xzswq21]

Where are you in the world? The offerings differ from region to region, and shipping heavy machines is costly. It's best to go for local offerings.
I don't need your adress or country, but region or just continent would help.

Asia but don't worry about the shipping cost. in the first step I should know several precision and small CNC machines.

[mac.6]

accuracy of 0.05mm doesn't mean anything if not specified over a length.
Because anything like 0.05mm over 300mm is in class C0/C1 ballscrew, so at least 1k$ per axle...
And to have this kind of accuracy you also need environment control room, otherwise it's just flushing money down the toilets...

[olkipukki]

I know several such machines, but the main question is: how big is your wallet?

... and how big is your place 

[xzswq21]

I know several such machines, but the main question is: how big is your wallet?

... and how big is your place 

In my workshop at our home!

[xzswq21]

I need a high accuracy mini CNC machines.

[langwadt]

I need a high accuracy mini CNC machines.

and to give any sensible response you need to define high accuracy, mini, and how big your budget is

[Benta]

I need a high accuracy mini CNC machines.

OK, just to give you an idea on offerings based on your wishes.

This is a small machine that will accommodate your needs regarding workpiece size and accuracy (Stepcraft D300):
https://www.stepcraft-systems.com/en/cnc-machines/d-series
Quite honestly, it's a toy. It will work for wood and plastics, but will be at its limit with aluminium. Forget brass and stainless steel. Just look at its weight.

This is somewhat better (CNC-STEP S400T):
https://www.cnc-step.de/cnc-fraese-high-z-s-400t-kugelgewindetrieb-400x300mm/
It will take your workpieces, it will machine aluminium and brass, and with care, also steel and certain stainless alloys.

Here's a machine that will do almost everything you want (Wabeco CC-F1200):
https://www.wabeco-remscheid.de/catalog/category/view/s/cc-f1200/id/341/
It will machine everything, including stainless steel. but it has a big limitation: the Y-axis working range is only 150 mm (~6").
Note that it's a cast iron machine (not aluminium), weighing in at around 105 kg. This feature is a Good Thing!

Now you've seen the price ranges for what are not even production machines, but rather hobby or prototyping. Feel free to have a heart attack.
Of course, copies/clones of these types of machines are available from China at perhaps half price.

The reason I especially mention stainless is, that except for a few alloys, it's hell to work with for a milling machine. It's either "gummy" when cutting, or even worse, it work hardens to glass brittleness, thus needing a very rigid machine with high feed rates.

[KaneTW]

Forget about CNC-STEP etc. They're not worth your money even as a hobbyist machine. CNC-STEP in particular vastly overpromises their specs.

First of all, your tolerances in the motion system must be tight enough. This means high-accuracy ball screws etc.
Secondly, open-loop steppers won't work here. You need a closed-loop system with a sufficiently exact encoder.
Thirdly, your machine must be very rigid and low on vibration. Cast iron or granite/etc base is required.

You mention stainless steel. Due to its propensity to work harden, you can't work slowly and you need flood coolant. This pretty much pushes you into big, enclosed machine territory.

For example, for stainless, you also need to keep your workpiece within 15C of reference temperature to achieve 50um/200mm accuracy.

You're looking at Haas Mini Mill (lighter use), DMG Mori M1 (heavier use), etc. at least imo. A Tormach 1100MX *might* be able to cut it, but that's closer to hobby territory.
So 5 digits for sure, the question is just whether it's 50k or 20k base.

[Benta]

Let's not go over the top. The OP specified 0.05 mm tolerances, which is not that hard to achieve.

But the aluminium based machines are either jokes or for plastic cutting. Cast iron is the thing.

[langwadt]

Let's not go over the top. The OP specified 0.05 mm tolerances, which is not that hard to achieve.

But the aluminium based machines are either jokes or for plastic cutting. Cast iron is the thing.

nonsense, https://youtu.be/_fPTYjScd_w

[AccountRemovedPerUsersRequest]

I have a CNC made of extruded aluminum rods and open-loop steppers. Here is an example of a routed PCB. Pads are 16mils and tracks are 12mils. How is this related to anything? Well, just sharing an example.

A

[thinkfat]

Let's not go over the top. The OP specified 0.05 mm tolerances, which is not that hard to achieve.

But the aluminium based machines are either jokes or for plastic cutting. Cast iron is the thing.

nonsense, https://youtu.be/_fPTYjScd_w

Stefan Gotteswinter is certainly a trustworthy source.

[Benta]

Let's not go over the top. The OP specified 0.05 mm tolerances, which is not that hard to achieve.

But the aluminium based machines are either jokes or for plastic cutting. Cast iron is the thing.

nonsense, https://youtu.be/_fPTYjScd_w

At around 15:xx he says: "it is not made for cutting steel, but you can make it do it." and then shows machining a 316 block, with ridiculously small cuts.
His selection of 316 is not random, 316 is one of the few stainless alloys that's can be machined without problems.

I'm not saying you can't make a machine from aluminium, but then it should have a frame/bed of much larger dimensions than on the hobby machines, and then you might as well go to cast iron directly. They'll weigh approximately the same.

And watch your tone, please.

[xzswq21]

Thanks for all your valuable comments
Can I make a customized CNC machine? There are a lot of used precision ball screw actuators and 5 phase stepping motor with encoder, these are stainless steel, plus I can design a controller to control the CNC machine, I think I should install the parts on a Iron frame and align the axes. I want to cut and bore small size pieces, 1"x2" teflon rod or a 4"x4" steel sheet with a 2mm (0.078") thickness,

[Benta]

Thanks for all your valuable comments
Can I make a customized CNC machine? There are a lot of used precision ball screw actuators and 5 phase stepping motor with encoder, these are stainless steel, plus I can design a controller to control the CNC machine, I think I should install the parts on a Iron frame and align the axes. I want to cut and bore small size pieces, 1"x2" teflon rod or a 4"x4" steel sheet with a 2mm (0.078") thickness,

Sure, lots of people do this and there are plenty of web sites describing how. The most difficult part is probably the integration with your CAD software.

[langwadt]

Let's not go over the top. The OP specified 0.05 mm tolerances, which is not that hard to achieve.

But the aluminium based machines are either jokes or for plastic cutting. Cast iron is the thing.

nonsense, https://youtu.be/_fPTYjScd_w

At around 15:xx he says: "it is not made for cutting steel, but you can make it do it." and then shows machining a 316 block, with ridiculously small cuts.
His selection of 316 is not random, 316 is one of the few stainless alloys that's can be machined without problems.

I'm not saying you can't make a machine from aluminium, but then it should have a frame/bed of much larger dimensions than on the hobby machines, and then you might as well go to cast iron directly. They'll weigh approximately the same.

And watch your tone, please.

you blatantly stated aluminum machines are "a joke" or plastic only, and while there are plenty of machines that are that (build in all kinds of materiels) that's just not true

[langwadt]

Thanks for all your valuable comments
Can I make a customized CNC machine? There are a lot of used precision ball screw actuators and 5 phase stepping motor with encoder, these are stainless steel, plus I can design a controller to control the CNC machine, I think I should install the parts on a Iron frame and align the axes. I want to cut and bore small size pieces, 1"x2" teflon rod or a 4"x4" steel sheet with a 2mm (0.078") thickness,

if you have to ask probably not, definitely not high precision

[sokoloff]

If you want to build your own machine, I think the first step is to become familiar with a commercial machine (ideally a low-end and a mid-grade machine separately), spend a couple hundred hours making parts and chips, and see what they did and why.

You wouldn’t start out trying to build a car or start a plumbing company today without experience of what already exists, right?

Is it doable? Of course! Is it a lot of work? Also of course.

[langwadt]

If you want to build your own machine, I think the first step is to become familiar with a commercial machine (ideally a low-end and a mid-grade machine separately), spend a couple hundred hours making parts and chips, and see what they did and why.

and a CNC is great help when building a CNC

[thinkfat]

For something DIY that can mill steel, here's Marco Reps router: https://youtu.be/vB_FvkllLPc

This is the Finale of the series.

Of course the frame is not aluminum.

[PaulAm]

Quote from: sokoloff on Today at 12:53:20 pm

    If you want to build your own machine, I think the first step is to become familiar with a commercial machine (ideally a low-end and a mid-grade machine separately), spend a couple hundred hours making parts and chips, and see what they did and why.


and a CNC is great help when building a CNC

At the very least, access to a machine shop with decent quality manual machines (and the knowledge and experience to use them).  If you don't know what you're doing, the only recourse is to pay somebody for their expertise and buy a machine or kit that meets your requirements.

One alternative is to get a cast iron bench mill drill (Chinese clones are all over the market) and then a refit CNC kit..  These things are > 1-300Kg, so not really that big as far as machines go.  Find the refit kit first before you get the mill though.

The only constant here is that it's going to cost a fair amount of money.  Precision and machining steel/stainless does not come cheap.