Joe,
You’re asking the million dollar question, and the answer is that there is no one answer. If you look at what is currently on the market for hobbyist CNC mills and routers there is a vast selection of very different capacities and capabilities.
Simple rules of the CNC hobby:
-Everyone wants one, many try to build one, only 0.5% get as far as cutting a single part.
-Everyone wants a huge machine, few have room for a machine larger than 12’x24’
-Everyone wants to cut aluminum, few need to cut aluminum, the best use for these cheep hobby machines is to build RC planes and other hobby components.
-Everyone wants to hold a 0.001”, a thou doesn’t mean squat in balsa wood b/c it expands and contracts with temperature and humidity. A hobbyist machine only needs to out perform what a man can do by hand two or three fold. So holding 0.015” is awesome.
-Ball screws are all the rage, ACME was the thing last year, you only need 1/4” allthread from homedepot with a cutting board plastic nut hand tapped.
-Don’t bother screwing with your own controller design. Current limiting resistors are a waste of time and amps. Get one of the fine 3 or 4 axis chopper boards pre assembled. Works great and no problems.
-NEMA23 steppers – EBAY.. your not ready for servos or Geckos.
-You can spend a lifetime on linear rail selection, gas pipe, drill rod, BWC, 80/20, Thompson, NSK, THK. Each more expensive that the previous. Gas Pipe can be rough, drill rod and roller skate bearings is tough to beat. Checking out the K.. B.. plans, they are worthwhile and they are inexpensive.
-MSCDirect.com is good
-McMaster.com is great
-EBAY.com is awesome!
So back to the million dollar question… the answer (for you) is..
1’x1.5’ cutting area
Dremel spindle
MDF construction
Allthread
Bearings of your choice
I have known several eng students who have started what are about to. Only one finished.. and I had to sell him a finished machine just before his senior presentation.
It took me 6 months to build my first machine from KB plans. It took me nearly 2 years to build my second machine (4’x4’x1’ all Aluminum). This is not a quick, easy, or cheap hobby.
Best of luck.
Tim T
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