CNC engraving of brass labels

[labelcnc]

Hi, I'm a new user to this forum and I hope it can help me.
I am looking at a couple of CNC routers advertised on Ebay with a view to engraving brass name plates on them. I have no problems with software, labels can be designed on anything from AutoCad look alikes to Solid works, transferred through MeshCam or similar.
It's whether anyone has used the machines for this purpose I am interested in, particularly will they be rigid enough.
Machines being looked at are:24338, and :24339.
Can anyone say if they have used these machines please?

[Wal]

In theory they should be rigid enough - brass cuts very well and if you're using small tools (2mm and less), you'll likely bust the end-mill before you run into morbid machine deflection... Having said that - they may be poorly built and you may get vibration and resonance leading to excessive small tool breakages and a rough looking cut..!

These ebay specials aren't that popular on the forum - many a tale told of configuration woes and poor cutting results... If it's really light duty stuff you're planning to put one of these to work on then you'll probably be alright - you may have to swap out a few parts here and there and persevere a bit with the config, but if you're game for that caper, then hey - they're a place to start.

(Probably not been that helpful here, have I..?)

Wal.

[labelcnc]

Thanks Wal, that's just the sort of feedback I'm after. I anticipate the duty to be light, 0.5 mm deep cuts, could be a relatively low feed rate and generally a small cutter as sharp(ish) internal corners are preferred.
Hopefully someone who has a machine will also come back.
Is there a thread running on configuration troubles?

Graham

[dfox1787]

i would stay away from the china cnc machines. I have spent more money repairing and replacing parts then i would if i just bought a good quality machine in the first place.

[cropwell]

I have got a light duty machine made in Devon (especially for cutting clotted cream :hysterical:) unsupported rails make deflection a problem and engraving brass is a matter of trial and error, mainly error.
Engraving bits (V chisels) simply chew the brass for me and I think that may be a vibration issue due to poor rigidity. I get better results with a small end mill, typically down to 0.4 mm. I have tried 0.2mm but those buggers are so delicate, they will break if you even look at them funny. I have to use very low feed rates and DOC's and lots of WD40.

If I were doing it as a commercial venture, I certainly wouldn't use a Chinese low cost gantry machine. The second machine looks better, but again column rigidity could be an issue.

[Wal]

>Is there a thread running on configuration troubles?

As it happens, there's a thread a couple down from this one:

http://www.mycncuk.com/threads/11054-My-Cheapo-Chineese-3020t-mini-CNC-Build-%28more-like-improvements%29-leanring-all-the-way

The machine is probably a near approximation of what you're proposing to purchase - as you can see, it's a bit of a project..!

Wal.

[labelcnc]

Thanks Wal, I did read through that one, fortunately for me I have considerably more machine knowledge than he exhibits. Don't believe he will ever get it going! I will have difficulties with configuration etc, but am far more concerned whether the machines are suitable. Beginning to look not.
2nd reply said to buy quality machine. What & where?

Graham

[A_Camera]

I am interested in, particularly will they be rigid enough.
24339.

Never used those two but if I'd buy one of those it would be the second one. I think it has much better rigidity than the first, assuming it does not use unsupported round rods.

[magicniner]

In the same position I'd be inclined to buy a basic Machine Mart bench top mill and convert it properly, they're not World Class but at least you'd be starting out with a half-decent structure in Cast Iron.