Help Me Choose a CNC

[crumpz]

I'm a complete newbie to the world of CNC, looking for guidance on making the right purchase.

I'm looking to help my wife lessen costs with her simple jewelry business. She makes hand stamped necklaces with custom designed stamps we get made. She stamps them onto circular blanks made out of sterling silver and gold fill (brass base). The blanks are 13mm x 13mm, and the stamped designs are around 9.5mm x 5mm.

The custom stamps get pretty expensive when we come up with new designs, so I thought a CNC machine would be a great way to lessen our custom stamp costs by engraving the designs instead of punching them with a stamp.

I've been thinking a Nomad 883 Pro would be the best option based off of my very limited understanding that it's capable of .001" accuracy. Admittedly, I'm not sure what that really means, other than I'm assuming the Nomad is capable of accurately engraving designs onto a very small area 13x13mm with designs that are around 9.5mm x 5mm.

I thought for sure the Nomad 883 Pro was the way to go for my needs, but the cost has always made me pause, it's not that I'm unwilling to spend that much, I just always wondered if there was a cheaper alternative to achieve what I wanted, since all I really want to do is engrave out simple designs onto a small area, and nothing more.

Can the MillRight M3 achieve what I'm looking to do on a small area?

[martin]

What are the stamps made of?

[crumpz]

The stamps are made out of stainless steel. I may be misunderstanding your questions, but I'm not looking to make custom steel stamps myself, but instead replacing the stamps with a CNC and engraving directly onto the disc blanks.

[martin]

Ah, yes, I misunderstood then.

First, I own a Mega-V, not an M3, so I cannot directly attest to the M3 itself.

Now, if you are already using a stamping process, going with engraving will change the look of the final result. Which is fine, but it's something to consider from an artistic perspective. I had to ... adjust my artistic vision ... when switching from manual engraving to a laser, for example.

I don't know your process, so I'm not really sure if you're primarily interested in accuracy vs. repeatability, but in the above I'm assuming accuracy (so in my usage if I tell the machine to cut a one inch slot, the slot is actually close to being one inch and stays one inch across the length of the slot).

Given that stamping is intrinsically, um, "rounded" (?? I mean to say that when you stamp, the metal has to deform to match the die, and this tends to create rounded edges rather than sharp right-angle edges), I'd be surprised if you couldn't do what you want with an M3, the right end mill, and a well-trammed machine. At any rate I would be comfortable doing it with my Mega-V.

[Bruce]

I just looked up the cost of the Nomad...wow! I would bet you could get the M3 and build an enclosure for half of that cost.

[crumpz]

Martin, thanks for getting back to me.

Is it wrong of me to assume a CNC that has better accuracy is capable of engraving smaller designs? In my case 9.5mm x 5mm engraving of a design onto 13mm x 13mm disc blank. I plan on using end mills that have 0.0025" to 0.005" tips to allow for as much detail as possible.

I've always assumed that the Nomad 883 was the right CNC for what I wanted to achieve since it markets it's accuracy as 0.005 inches. Admittedly I'm not entirely sure what this means, but I assume it can move around the x,y,z axis with that level of precision.

I haven't been able to find what level of accuracy the M3 claims to have, which is what my initial concerns were with the M3. Do I even need that level of accuracy for what I'm trying to do?

Bruce, the price of a Nomad has definitely made me take pause. Being so new to CNC, I wonder if I can get away with an M3 and achieve what I'm trying to do. Although the plug and play aspect of the Nomad definitely appeals to a newbie such as myself, but if I can achieve a similar result w/ an M3, I'm willing to go through some struggles to save a chunk of change.

[rowiac]

If you are planning to engrave in soft materials, the M3 should be able to do it with an accuracy of 0.005", especially in the small sizes you are asking about. Accuracy gets more difficult with larger projects. The M3 uses a trim router (e.g., DeWalt or Makita) which only come with 1/4" collets. You will to get a 1/8" collet to use the smaller endmills you will need.