CNC engraver for clock dials

[mbhorology]

A few years ago I looked into a suitable machine for clock dial engraving but didn't really get anywhere as I didn't really get any positive vibes about the machines available on the market.

I've posted a picture below of a hand painted dial I have made previously and I'd like to reproduce this by engraving on CZ120 brass.



The depth of engraving doesn't need to be deep and I don't care about running a machine at very slow feed rates, but I do want to achieve crisp engraving with curves which do not have visible steps.

I'm exploring what is available again and it appears that in the UK Sainsmart and FoxAlien appear to be the budget machine suppliers. I'm aiming for a machine with ball screws for accuracy.

I've spotted the Sainsmart 3030-ProVer Max https://www.sainsmart.com/products/3030-prover-max and wondered if people thought this might meet my needs? The design looks sturdy and it claims to be suitable for metal. My feeling is the spindle would need upgrading...

[JohnHaine]

A good question, I've been wondering the same thing! I have a small CNC mill and have done small engraving jobs but I need to do a 300mm dia dial somehow. This one looks quite good but the steppers seem a little small for comfort, I'd rather see NEMA23s for a machine this size I think.

[mbhorology]

It's a fair point about the stepper motors. Whilst the design looks more sturdy on the 3030 as the bed moves instead of the gantry this model which does move the gantry has NEMA23 steppers and closed loop ones too. https://www.sainsmart.com/products/proverxl-4030-v2

The ProverXL 4030 is a little more expensive, but I'd still like to get confidence it will work for me...

[JohnHaine]

Only double the price..

I like the dial you made!

[mbhorology]

Thanks for the comment on the dial. I just noticed that the image was on its side - no idea how that happened!

Indeed twice the price, but having made expensive mistakes in the past ended up purchasing a 2nd time this is something I'd like to get right.

Having taken some advice from a friend who know more about CNC machines, I'm on the verge of considering the FoxAlien Vasto machine which uses linear rails and 16mm ball screws. The spindle I suspect with a max speed of 10000rpm is something which needs upgrading for engraving, but its a good starting point if I run the machine a slow feed rates. I'm not under any illusions this machine can be run fast as the design of these things is not as sturdy as my Centec mill for example, but the Y travel of this format of machine isn't any good for the surface I want to be engraving.

I'll report back on how I get on. CNC is completely new to me as I'm very much a manual machine tool user.

[JohnHaine]

That does look like a more capable machine. I don't think you should worry too much about spindle speed - my little Novamill runs at 5000rpm max and I have engraved brass with a 1mm end mill and PCB using TCT engraving bits quite happily - you just have to run slower. Of course you also need some form of CAD/CAM to generate gcode, I variously use FENGRAVE (which is free and very good for engraving, outputs usable gcode directly) or more generally CAMBAM which is more a CAM program though it also gives basic CAD, it can generate engraving code too. Very reasonable cost. If you go ahead might I commission a dial from you?