[itarnyagin]

Hi
I'm planning on building a CNC router. It will be medium/large size, and I will first design it in fusion 360, and then make it in real life. I've researched cncs, and routers for some time now, but I still have some questions.
The goal for my build is to make/cut out big pieces of wood, and some soft metals like aluminium, and maby even hard once, like steel. I know that the frame of my cnc should be more ridgit than what I'm cutting, but how do I calculate that, or how do I know if my frame is good enough? And what type of spindle do I need? What RPM? What wattage? Any advice on picking stepper motors?

My price range for the machine is $500 - $1000

Sincerely Ivan

[coherent]

Forget about any cnc router for steel unless you spend big big money to buy or build it. You can cnc steel with a plasma cutter, mill or laser but not a router setup. It sounds like you are fairly new here and your question is kind of basic and your budget is pretty small for anything very large. If I were you, I would search the forum and do a lot of reading. Find a router or plans that fit your needs, capability, cost etc, then go from there with something that has been tested and proven. Engineering a machine from scratch and trying to determine how ridged it will be depends on many factors based on each component and material. If you were a structural engineer then I don't think you'd be asking the questions you asked, so research here and elsewhere on the web and copy or buy something that you know will work.

[itarnyagin]

Forget about any cnc router for steel unless you spend big big money to buy or build it. You can cnc steel with a plasma cutter, mill or laser but not a router setup. It sounds like you are fairly new here and your question is kind of basic and your budget is pretty small for anything very large. If I were you, I would search the forum and do a lot of reading. Find a router or plans that fit your needs, capability, cost etc, then go from there with something that has been tested and proven. Engineering a machine from scratch and trying to determine how ridged it will be depends on many factors based on each component and material. If you were a structural engineer then I don't think you'd be asking the questions you asked, so research here and elsewhere on the web and copy or buy something that you know will work.

Thanks a lot!

[awerby]

How are you planning to build this - are you welding the frame using steel, or bolting pieces of extrusion together, or making a frame out of MDF? Are you using screws or rack-and-pinion drive? What kind of rails are you putting on it? Just about any way you go about it, you're going to have used up that budget by the time you've got the frame built. But that's okay - spend your money on the frame and while you're saving up for the control system you can research spindles, steppers, and drivers. To get you started: for wood, you'll want a 3-phase spindle with a VFD that runs at about 18,000 RPM. Reserve some money for a dust-collection system; if you make nothing else, you'll make a lot of dust. When buying steppers, look for ones with low induction, not high holding torque. And when shopping for drivers, avoid the cheapest ones.

[joeavaerage]

Hi,
I concurr, you will not get any machine in your budget with anything like enough rigidity to cut steel, you might get away with light
engraving of aluminum but forget trying to machine aluminum parts, you need a rigid machine, thousands to ten of thousands of
dollars worth!

I am building a mill (my second) with only 350mm x 350mm x 350mm travels but rigid enough for heavy duty steel and stainless. The grey cast iron
mill axis beds and the SG iron upright frame will cost over $5000USD to have cast for me. That does not count the linear rails, nor the
ground ballscrews nor the AC servos nor the spindle(s)....that's just the cost of the metalwork to which all the good bits are bolted!!

There are vast numbers of cheap Chinese made CNC machines out there that have been bought and no-one has been able to get to work.
You could pick up a bargain, in fact with your budget you will need a bargain.

The advice is do a whole bunch of research here and elsewhere so that when you are scanning Ebay/Aliexpress etc. that you know what you are
looking at. The norm with advertising is to make a machine look way better than it actually is, its your job as buyer to strip away the crap and
assess the true value of the item(s) offered.

Craig

[peteeng]

Hi Ivan - I designed a router from scratch here. Look up Maximus. It starts from white paper and ends up costed. Don't even think about steel for your first machine or any "router". Even aluminium is a big step up. Especially since you say med/large size. Have a look at mills that have the table size you think you want. They weight several tonnes for a reason. Keep making. Peter

https://www.cnczone.com/forums/austr...76822-cad.html

At your price point I suggest you build a plywood machine with metal rails. There are many in this forum. Easy to do things yourself, easy to change and the performance is very good to excellent if you work it through properly. I'd even expect it to cut Aluminium if done right but not steel. Design it and test it in F360 even optimise parts in F360. good Making its a long journey...

[itarnyagin]

Thanks a lot!