[denversash]

Hi everyone,

I'm a total newb to CNC. I manage a granite distributing company that sells a lot of bathroom vanity tops. 99% of the tops are 22" x X" x .79" (2cm).

Currently we outsource all of these tops to a fabricator in china because we don't have the tooling to make the sink cutouts. I'm trying to put together a CNC setup so we can start doing the sink cutouts in house. The biggest sink is maybe 22" x 17" so we don't have a very large area we're working with. Our longest slab is currently 75".

I'm thinking we can use a 4'x4' CNC router and build a couple small tables for each end to support the granite for long slabs (up to 8ft).

I've been visiting a lot of manufacturer websites and seeing some very pricey equipment. Not sure where to go from here. It looks like these are the types of bits I would need to use. I could probably rig up a separate water spraying cooling system, but would need to see how the router is setup first.

Any recommendations on where to go from here?

Thank you!

[denversash]

Oh I should also note this would not be very high usage. I think we would on average 2 countertops per day so the machine would be used 1 hour per day.

[hjcraver]

marble CNC router machine 900*1500mm products, buy marble CNC router machine 900*1500mm products from alibaba.com


You may want to consider a machine from China. Their Quality is a lot better than you may think. This machine will cut marble but I dont think a machine like this will cut Granite. It will probably take a waterjet machine for that, which is in another cost league.There are Waterjet fabricators in about every major city in the US. HJC

[judleroy]

You will need a machine that is very heavy duty to do this job. If you can find a large travel cnc mill for a decent price used thats your best bet. You will need to core a couple of holes then rout with a finger bit. The tools are fairly expensive and require throuh tool coolant to work correctly. Do you polish in house? The reason I ask is you will probably need a set of tools to smooth the cutout and roundover the top edge. That takes four tools. If you want to polish on the machine that will require 3 more polishing tools that are matched to your 4 edge tools. For the finger bits its 75-100 dollars a piece, 13/8 core drills are about the same. The edge finishing tools are about 1500-2500 a set and polishers are another 800-900 dollars a set. The tool holders are special also and aroud 100 dollars each. (must have one for each tool). A decent granite machine used is 65,000 and up. New, 150,000 or more. A decent large used cnc mill which really needs auto tool change is probably going to set you back 25-50,000 dollars unless you get lucky. Don't forget you must have through tool coolant. If you need any more info I'll help if I can. Good luck
Judleroy

[judleroy]

On a side note a decent granite fabricator can cut the sink openings with a wet grinder and smooth and polish with a wet sander. With the right sanding pads and blades of course. The tools to do this would set you back a 2-3000 dollars and the right fabricator. He'll need 12-15 dollars an hour. More if he's real good.
Judleroy

[cncengraver]

this heavy structurer could support more than 1000kg weight.Also it's stable without vibration.

I think cnc router could engrave charactors/flowers and all kinds of relief.But i don't think it's good to cutting stone. may be the marble sheet is available for cutting.

[judleroy]

That router could possibly cut the sink cutouts but it would need a spindle with cat 40 tooling and 5-10hp to be really effective. The granite tools need 1000-7000 rpm. That spindle will most likely not go below 8000 rpm. If they could offer a better spindle option with through tool coolant you could be in business.
Judleroy

[cncengraver]

yes i agree with you and 4.5kw spindle will be good for the hard work.

constant power spindle work at low rpm it can keep good torque less than 8000rpm. it maybe the good option.

[parsson]

Check out the German Heiz RaptorX-SL.
Heiz makes incredible machines with a stellar performance/cost ratio. Quality without costing an arm and a leg

Haven't seen the RaptorX-SL in action myself yet. Only the smaller bench top machines in the HighZ series.

Video of RaptorX SL for stone machining
‪Croftmania's Channel‬‏ - YouTube

Link their website with some info on the new stone cutting RaptorX.
Stone+Tec, Stonetec fair exhibition granite picture engraving