Which machine for headstones - please help.

[Dan2020]

Morning all,

I have been looking into getting a cnc machine that will carve letters into stone, this would include sandstone, granite and marble.

I have no idea what it is that I am looking for.

I was looking at the x-carve ones but i don't know if it would be powerful enough to engrave stone.

Could someone please advise what cnc machine(s) would be best for this type of work, which would be within an affordable range, would i be able to get one for around £5000? where would I get one from, could someone advise of a decent supplier preferably within the uk?

Many thanks for any help

Dan

[Clive S]

Dan welcome to the forum.
You need to say what size machine you are looking for ie headstones etc etc

Edit: I have just noticed that you need it FOR headstones. Headstones probably can weigh up to a ton son some sort of lifting equipment is also needed. 5K would not even be close.

[magicniner]

You will need to use Diamond tooling for stone, that will not leave you any margin of forgiveness for vibration so rigidity will be important as will flood coolant and protected ways.
My thoughts are that your budget is an order of magnitude low for anything which might do the job well and last a reasonable period of time in service.

[JAZZCNC]

I was looking at the x-carve ones but i don't know if it would be powerful enough to engrave stone.

Could someone please advise what cnc machine(s) would be best for this type of work, which would be within an affordable range, would i be able to get one for around £5000? where would I get one from, could someone advise of a decent supplier preferably within the uk?

Hi Dan,

First, forget any of the cheap machines like X-carve, etc, they struggle to cut hardwoods correctly let alone any type of stone.

To be honest you have no chance of buying a new machine capable of cutting Granite or Marble with £5k. Not even a small one.!
It's not even possible to DIY build a machine that would be reliable and strong enough with £5k. The correct spindle setup alone will cost £5k or more.

I build bespoke machines for people, mostly wood-routers, but I do have a little experience with the type of machine you need as I helped build a large machine for friend who cuts Marble/granite work surfaces and while the Stone cutting machines you'll see work and look just like wood-routers they need to be built much stronger and with different components that handle water and cutting forces involved.

The spindles used are lower RPM with high torque, more akin to what's used on a milling machine. Typical RPM for Engraving granite with V-shaped PCD tooling is 6000-8000Rpm. Most spindles used for wood won't spin this low and still have any usable torque left.
When you get into hole boring or using what they call parallel routing cutters your down into the 1000-3000Krpm range.

Then you have the cost of tooling, if you are into cutting stone you'll know how expensive PCD tooling is, but when you get into CNC tooling or CNC Profile cutters for edge cutting and polishing, etc it gets eye-watering.
Edge profiling/polishers come as a 7 piece set, the first 4 tools cuts and prepare the stone and the last 3 polish the edge. Each set costs £1800 and you need a set for each profile shape.!!!

So what I'm trying to get over is that unless you are prepared to spend at least £10k on the machine, even one that is only large enough to cut a single headstone and just to use for Engraving let alone a full 12' x 6' slab and profiling, etc then forget it. It's a different beast of a machine that's required.

Also, don't be fooled if you've seen Routers like X-carve, etc cutting stone or marble, etc on Youtube, or even more sturdy machines for that matter, because while they'll manage a video or two the won't stand up to constant use or even decent part-time use before they become sloppier than whores flu and the spindle goes into meltdown. Those taking the videos won't ever tell you this.!

I'll PM you my number if you want to have a chat I'll give you any help or advice I can. I'm up the road in Goole if you ever want to come to see a machine being built or working.

Edit: Dan you are still in the clearing stage because new to the forum so I cannot PM you yet, write a few more posts, I think it's ten needed then it will let you PM.

[Boyan Silyavski]

For that money and probably a bit more you could build one for engraving, but definitely not for cutting. Say 120x120cm. , bed must be low, gantry sides raised. Overbuild gantry and Z. 3kw spindle will do the engraving, no problem. Wet of course, or sth like a mist system. Stone could be machined dry, but lower tool life and you have to have a good vacuum system and shoe.
Again, only engraving. shallow pocketing and probably shallow 3d jobs.

Now the challenge is - how big a slab you would deal with. With anything over 50kg i would say you are looking at 10k at least spent.


Damn that X Carve stupid videos, these people should be blocked from youtube.


Now there are impact engraving machines and laser engraving machines, that are light cheap and not so cheap/ the laser ones/ that may suit you better as they are focused on producing exactly that niche products.

[JAZZCNC]

3kw spindle will do the engraving, no problem. Wet of course, or sth like a mist system. Stone could be machined dry, but lower tool life and you have to have a good vacuum system and shoe.

Boyan if you are talking about the 3Kw router type spindles then they will not handle engraving Granite or Marble with industrial-grade PCD tooling. Typical RPM is between 6000-8000rpm and these spindles don't have enough low down torque. Also, they cannot handle the loads for any lengthy periods.
I built my friend a machine just for cutting the draining boards, we used one of these and killed it within 3 months. They will work ok for the occasional jobs but no good for 10hr days week in week out.

[Boyan Silyavski]

Boyan if you are talking about the 3Kw router type spindles then they will not handle engraving Granite or Marble with industrial-grade PCD tooling. Typical RPM is between 6000-8000rpm and these spindles don't have enough low down torque. Also, they cannot handle the loads for any lengthy periods.
I built my friend a machine just for cutting the draining boards, we used one of these and killed it within 3 months. They will work ok for the occasional jobs but no good for 10hr days week in week out.

I agree, GDZ on their 5kw GDZ125-18Z/5.5 spindles say bearings for half year, other parts for one year
. Which i see as a perfect engraving spindle for DIY projects. They come with 2*7007C P4
2*7005C P4 bearings.

So spindle is consumable, at 500$. One pays it off on a couple of jobs and then when broken, bearings are to be changed. bearings are at around 100$ the pair, so
its quite doable and i see it as an solution.


Again, not for cutting, just for shallow jobs. I kniow what you are saying, i have the diamond bits but still have not done that on mine machine, not that it wil not do it, but dont want to loose precision or hack the bearings. But if a job that pays well comes, i will do it.


What i am saying it is a viable solution to start the business and make money. A mill head could be used also , but i dont see the point.

[JAZZCNC]

I agree, GDZ on their 5kw GDZ125-18Z/5.5 spindles say bearings for half year, other parts for one year
. Which i see as a perfect engraving spindle for DIY projects. They come with 2*7007C P4
2*7005C P4 bearings.

So spindle is consumable, at 500$. One pays it off on a couple of jobs and then when broken, bearings are to be changed. bearings are at around 100$ the pair, so
its quite doable and i see it as an solution.


Again, not for cutting, just for shallow jobs. I kniow what you are saying, i have the diamond bits but still have not done that on mine machine, not that it wil not do it, but dont want to loose precision or hack the bearings. But if a job that pays well comes, i will do it.


What i am saying it is a viable solution to start the business and make money. A mill head could be used also , but i dont see the point.

We are on different wavelengths here. I'm talking about a machine that will be used in a business environment solely dedicated to cutting and engraving all types of very hard materials, stone, marble, granite working 5-6 days 8-12hrs.

The last thing any business want's whether it's a new or long-standing business is unplanned downtime or continuous unreliability. These spindles are simply just not up to the job for what's described above. Changing out the bearings isn't something a hairy arsed stone mason wants or needs to be doing or even swapping out spindles for that matter. Which he would be doing often with these spindles.

I'm dealing with small business users all the time and just half a day of lost production can cause them major problems with both finance and reputation.
It's the holy grail of machine-building to me that reliability trumps all other aspects because it doesn't matter if it's the fastest machine or the largest machine or the strongest machine that gives a perfect finish because if that spindle isn't turning it's not making money.!! . . . And that applies to both large and small businesses.

[Boyan Silyavski]

All right , but what spindle you suggest for such a machine?

if someone has stone machinery he will definitely not cut it on the CNC to squares and such. And if a shape cut is needed the Waterjet Cut is used. So again we are there that spindle is used for engraving.

I said change bearings, yeah for DIYer . Change spindle for a stone mason or send spindle for change of bearings. What, HSD spindle bearings are eternal ???? Nope, you send spindle to a company to refurbish costing probably 2-3k.


And again, what about puch engraving. I doubt final client would care if V carved or punched, as far as there is a nice result. Otherwise laser engraving would not exist.

[phill05]

Morning all,

I have been looking into getting a cnc machine that will carve letters into stone, this would include sandstone, granite and marble.

I have no idea what it is that I am looking for.

I was looking at the x-carve ones but i don't know if it would be powerful enough to engrave stone.

Could someone please advise what cnc machine(s) would be best for this type of work, which would be within an affordable range, would i be able to get one for around £5000? where would I get one from, could someone advise of a decent supplier preferably within the uk?

Many thanks for any help

Dan

In answer to your question straight from a user, you would not get a stone cutting machine for £5k, we spent £7500 for the basic machine direct from China plus shipping plus taxes plus delivery from port.



This was in 2012 the machine is 1.8m x 1.4 bed it has a 5.5kw 24000 rpm water cooled spindle on ER 32 collets, it has never had to be run higher than 16000 rpm, In 2015 we had to change the controller from DSP to Mach3 (down time 2 days), In 2017 I fitted new bearings to spindle (downtime 1 week ordering the bearings 2 days fitting) the machine has been run day and night over weeks at a time, from 2012 to date.
For the different stone, granite, marble, Stone you can use Diamond tools for edge work, roughing out and levelling, Carbide for profile cuts, cutting text in Granite you use PCD (poly crystal diamond) for marble you use PCD or carbide.
I grind carbide into shapes to use all the time and they cut really well with plenty of water, we cut 2 1/2D highly detailed reliefs in stone memorials.
In my opinion don't discount the Chinese machines yes there is problems with controllers but this is something you can overcome by using them to earn some extra to pay for a better system.

Phill