Which machine for headstones - please help.

[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.

[JAZZCNC]

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

This is the problem it gets expensive very quickly for the correct spindle. Only a few manufacturers make spindles truely designed for stone,granite etc. The ones i know of are VEM which is an italian company and HSK who make spindles for just about every type of machine.
The correct spindle as a hollow Stainless steel shaft for water cooling and flushing, much like thru coolant on Mill's. They also often have extra bearings in the nose.
The prices are silly.!

http://vem.it/

My friend ended up buying a from a Chinese supplier. It was basically a modified BT40 milling spindle head with Stainless steel shaft and thru coolant. It was separate motor type not Electro spindle like 3Kw types.

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.

Yes and no. Yes for straight cuts they use a cutting saw because it's quicker. But for Sink holes etc or shaped designs like Workstaions etc they do cut the shapes with parallel rourter cutters. Also how do you think they form the edge profiles after the Water jet cuts the shape.?
The Big boys do indeed use Water jets for speed but they are very very expensive to buy and run so you'll find most of the smaller worktop people actually do it manually or with a CNC machine. My friend did it all manually for a very long time untill we built him the CNC machine. We are planning the next version that will be much larger and have twin gantry's for cutting and milling.!! . . . The prices of Stone cutting CNC machines is eye watering.!!

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.

None. But 3 months isn't an acceptable life span which is how long the 3Kw lasted before the bearings gave up. Plus it wasn't doing a very hard job, it was only fluting draining boards. The water is what killed it mostly and the tooling MUST be run with water and lots of it.

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.

Boyan, I've no idea about these other methods and I'm not disagreeing with you just for the sake of it. I know these 3Kw spindles cannot handle the water required for the tooling to work correctly and last Engraving or cutting Marble and Granite, sandstone and softer stones yes possibly if Air/Extraction is used but in the main they are too fast and too weak for a proper Stone cutting machine which will cut harder material like the OP asked about.