Frage Engraving stone with a Stepcraft

Hi all,

just thought I would post about some engraving I've been doing in stone on my Stepcraft 420 (1).

Wasn't sure I would be able to engrave in stone - but after a bit of experimenting I'm getting some decent results now, I think.

Below is a pic of some engraving I did yesterday in a Travertine stone tile, and the other picture is my stone engraving set up.

Happy to answer any questions if anyone is interested.

cheers

Looks great! Which mills & speeds did you use?

Hi Frank,

thanks for the comment.

For this engraving I used a 6mm shank 90 degree PCD bit, which I ran at 6mm/sec with 0.5mm pass depth. I had my HF spindle running at 75% and the cutter sounded fairly happy at those feeds and speeds.

The PCD engraving bit was one I bought on Aliexpress and it seems good quality so far. I haven't used a PCD bit before, but apparently the cutting edge is formed from a metal infused with small diamonds.

I think you might be able to run these diamond tools dry (with good dust extraction), but I ran them in the waterbath I made for my 420. Other diamond tooling I use needs to be kept cool - hence the need for water - but I think PCD bits might be different from other diamond tooling.

I can look for a link to the PCD bits I bought from Aliexpress if you like.

regards,

Duncan

Thanks for the many answers! If you ask Google for 6mm 90 PCD you get directly to Alibaba

Anyhow, did not work with Waterbed so far but noted it in case I get asked to do something similar.

Hi Frank,

you're welcome

Yes - there's plenty of PCD bits on Aliexpress (which is the easier to use version of Alibaba, I find

Some PCD bits are only intended for woodworking - so worth checking to make sure any bits are designed for stone.

I'm still getting used to using these bits - seem very good so far. I'm sure I read somewhere that you can engrave stone with them without using water cooling. Haven't tried it with these bits yet - but at my work we engrave slate "dry" with carbide bits all the time and it works fine.

I prefer to use the waterbath for my Stepcraft not because the PCD bits need it, but often I will be using other bits that are brazed diamond or sintered diamond - and they definitely work better with water cooling.

So its easier for me to just do all my stone work in the waterbath.

Of course I have to be careful with this waterbath as electricity and water are not great together!!!

It took me quite a while to perfect the waterbath so I felt confident that water wasn't going anywhere where it could create trouble!!

regards

Duncan

Hello everyone!

Duncan, I was when I took a look at you test engraving in the travertine stone ..
This looks so promising with regards to signs making.
I'm new here and just about purchasing my first CNC and looks it's gonna be 420 Stepcraft..

I'd love to carve V-grooved lettering in a piece of slate.. I think it is softer than the stone you worked with.

Duncan,
Great Job.

Hi Mike,

Cheers for your comments

I've enjoyed using my stepcraft to teach myself about cnc, it's a system where there are all sorts of accessories that you can buy for it to turn it into a milling machine, engraving machine, 3d printer etc, etc, etc.

For me that is the strength of the Stepcraft system - its great to explore all sorts of different avenues.

With respect, one thing I don't think it is, is a production machine.

The stone engraving I did was great fun and I learned so much, but it is a LOT slower than even an entry level engraving machine would be.

There is only so much you can ask of a stepcraft, so you have to run it within its limits.

I don't mean this as a criticism of the steppi- its a quality little machine for what it is. For me it's worked out great because all I wanted my steppi to do was teach me CNC and have a machine I can experiment with. It's done that very well

If you are intending to use a steppi to handle any commercial production then you will probably find you very quickly outgrow it's capacity.

The travertine I engraved was pretty soft as stone goes, but so is slate (usually!) so you should be OK doing a bit of engraving on that.

If there's anything else you want to ask then please feel free.

Regards.