[halfghan]

Hey everyone! Looking for some opinions here before I begin down the rabbit hole of browsing the endless threads/cnc resources online. I'm very much new to CNC, and would love to hear your opinions on what you would build yourselves given the following constraints:

• $1500'ish budget, NOT including software/computer. (willing to spend a little more if reasoning is justified/needed)
• Moving gantry (I'm working out of a 1 car garage and already have a TON of woodworking/beer homebrewing equipment, so space is at a premium)
• 18"x24" minimum size...Would love to go larger, but dont have space currently. Ideally would be upgradeable/expandable in the future?
• Needs to be rigid enough to cut aluminum. Would like to eventually be able to mill out logos/custom branding irons, etc out of aluminum.

Ultimately, this will be used for making custom beer tap handles, custom signs/logos/lettering, etc. Also would love to be able to mill aluminum to make 3D logos/lettering in aluminum.

Where would you guys start? What components would you buy? Belt drive vs screw? Stepper vs Servo? etc.

Basically if this were your money, what would you buy? Thanks so much in advance for any help you guys can provide!

[awerby]

Your budget is on the low side for building a machine that will deal with wood; I don't think it's enough to build one that could do 3D carving in aluminum. Steppers are cheaper and easier to drive than servos, so they're probably what you'll use. I'd advise spending the money for a good controller, like the Gecko G540, and get steppers with about 200-400 oz-in of holding torque with as low induction as you can manage (between 2-3 mh). Give it a 48v 10 amp power supply. If you build your own enclosure for the drives and PS, you'll save some money. But figure at least $500 for the control box and motors.

Belt drive is used in 3D printers, but not in routers; it's not positive enough to deal with cutting forces. If you keep it to 18" x 24" you can use a single screw to drive the long axis (moving the gantry); multi-start acme screws and matching nuts would probably be your best bet for all the axes. You'll also need some couplers; Oldham type or at least pieces of heavy rubber hose to connect the motors to the screws. You'll also need bearings for the driven ends of the screws, unless you go with rack-and-pinion drives. The far ends can run in cheap bushings, just to keep them from flopping around. If you can weld, building the table from steel is best; the weight's not a problem if it doesn't have to move. Use a piece of rectangular aluminum tubing for the gantry span, and thick aluminum plate for the sides of it. You'll probably use supported Thompson (round) rail for slides, unless you find a great price on square-section rails and trucks. Figure at least $1000 for all this stuff, and that's assuming you're getting great deals on it. You'll still need miscellaneous bits and pieces of aluminum to build your Z axis, and a router to mount on it, but maybe you have all that lying around already...

[ger21]

Here's what it costs for a decent machine in the size you're looking for.
Benchtop Basic CNC Machine Kit | CNCRouterParts

[ianagos]

I believe it can be done. But you must be thrifty, buying used is your only option on the electronics. Deals can be found. Also you can have linear rails and ball screws for about $500 shipped directly from china just ask chai.at linear motion bearings 2008 for a quote. And for the frame you can buy 80/20 relatively cheAp nos from ebay or something

So in the end it should come out to about $1750
Screws and rails ($500)
Electronics ($500)
Frame and bolts etc ($500)
Spindle ( cheAp used router) and other misc($250)

[Devastator]

Cost depends on a lot of things. I built a machine with 24X48 cut area for $500, but most parts came from dumpsters and it took years to build. I spent money where it counted, like multi-start leadscrews.

[halfghan]

I really appreciate the replies so far! Definitely some great points and lots to think about. I dont really have a timeline on this project, so I dont mind piecing it together as I come across great deals.

[Devastator]

Just keep in mind that it can be an empty goal, because after you build your low cost machine, you still have to buy software and tooling to run it. It was the only way I could get started though. If I had told my wife the true cost from the beginning, I would have been shot down before I got started. After the machine was built and I proved it could make money and improve the quality of the products we were already making, the software and tooling was an easy sell.

It has freed up a lot of my time and I can now do other things with my family instead of cutting parts by hand.

[halfghan]

Yep, i'm totally cool with all that. Im an avid woodworker already, and have several routers and end mills that will fit the bill quite nicely I think. I make and sell beer tap handles that are very router intensive, and i'm currently doing it all by hand with the use of several jigs and dedicated routers for each step. My hope is that the CNC will do the same for me as it did for you. Give me more time with the family instead of doing each router task by hand.

[halfghan]

And to clarify, I'm not looking to do 3D in aluminum. Only in wood. Only 2D(?) in aluminum. (What is the correct term for this?)