Advices for speeding up engrave process in brass (leather stamp for embossing)

[ovisopa]

Hello guys, I'm a newbie in CNC world, a afew months ago I bought a 900x600mm CNC (2.5kw spindle, NEMA 34 steppers), in the last few months I have milled different things in aluminium and plastic, now I need to make some brass stamps and I think is extremely slow (I tried speeding up but but breaked the tip of a few Vbits)

Usually for most of my operations I like to work with cambam, but for those stamps I think vectric is better (or my cambam knowledge is not enough), the problem is that either I can't find the option or there is no option to set the amount of stock to leave after the clearance operation, beacause I think the default value is to high.

I attached a photo so you can see the toolpaths one by one, I have 2 different operations but both operation have a different clearance tool.

1. 2mm endmill with a 5mm endmill clearance tool
2. 0.2mm Vbit with a 0.5mm Vbit clearance tool

I don't want to discuss about the first operation as it's not too slow, but the second operation , especially with 0.2m vbit is quite slow, I want to ask you what feeds you guys use for tools small as this: 30 degree vbit with 0.2mm tip. I use
- Feed of 1mm/second,
- Plunge: 0.5mm/second
- Stepover :0.08mm,
- Pass depth: 0.1mm

I really appreciate any help from you guys, what settings do you use when mill brass with so sharp tools ? And where do you buy the vbits from or what brand ?

The lines on the top where the horse is drawn are 0.14mm thick, the letters differ but for example, the letter T is 0.7mm thick.

Any advices are welcome as now my CNC is running for ~ 7 - 8 hours to finish a stamp like this

Similar Threads:

• Need Help!- TruTops (Trumpf) Punch -- Can't process Embossing Punches Automatically
• I can't engrave Rubber Stamp with my CO2 40W laser machine
• Need Help!- Can a laser cutting/engraving machine do leather embossing?
• Any Way To Cut/stamp out Leather Pieces Without Spending Thousands?

[ovisopa]

The second issue is related to cuting air, So much time is lost by cutting air especially on the exteriors, I think I chosed to correct operation , V-carve in aspire, I tried with profile but some letters ware not ok, much more thicker and the extremities was cut .

I attached a photo with the selected vectors and the generated toolpath.

Thank you.

[aarggh]

I buy loads of these kinds of solid carbide or sometimes HSS cutters from Chinese sellers on Ebay as they're dirt cheap. The only wear/damage I've had on any over the years is accidental plunging into hard material. With these very fine tips you need to really slow the plunge, but once it's cutting you can ramp it up a lot more than your doing. I should think at least 10 to 20 times faster, but just ramp it up gradually and see how well it copes with the chipload.

With Aspire, if your cutting air a lot, set the starting cut point in the toolpath settings lower.

cheers, Ian

[ovisopa]

Thanks Ian, the ebay link is not working but I got the last batch from AUTO HID PRO store on ebay, previously I got them from a local store but trashed a Datron vbit and a Djtol premium bit by mistake and than moved to chinese ones, never had the chance to try the Datron vbit on brass, I think I'll have to buy another set to see if it worts to pay 10x more.

I can't find any option for ramping up the feed after plunge, my plunge speed is 0.5mm / sec, with the 0.2mm tip this seem to be fine, I have just a few options on the V-carve milling operation

I wish the profile operation with a vbit tool worked better but even enabling / disabling sharp internal/external corners didn't made te simulation look good, tried once and the milled brass was even worse than the simulation.

Am I choosing the correct operation (vcarve) ? Is there a better way / software to make those brass stamps efficiently ? How could I only generate toolpaths on the exterior of the vector after the clearance operation ? as you can see in the photo bellow the toolpaths are generated for the entire space around the letter which is already milled by previous operations and clearance toolpath with the 0.5mm vbit



Any other advices are welcome.

[ovisopa]

In the end I couldn't find any way to make these stamps faster , I belive if no one ansewered there really isn't any way to make these in a efficient way using Vectric.

I'm glad I tried again using CamBam because with the help of some users on cambam forum now I can mill these stamps much much more quicker than with vectric or artcam express (whithout smart engraving module).

Check out the attachment , in the left side CamBam is twice as fast as Vectric defined the toolpaths, but still cutting way to much air (vectric is making two slopes, one for the angled profile, and another one on the exterior, you can see in my previeous pics),
on the right side you can see the toolpaths generated by Cambam with only one MOP , and there is another option so I can remove the exterior toolpath and keep only the slope profile. And before this finish pass made in 0.1mm increments on Z, I have just another MOP with a 1.5mm flat endmill, around the same profile but with a roughing clearance of 0.1mm and a much higher feedrate than the tiny vbit used in the finish pass.

Cambam is the way to go I really wished that someone can show me that vectric is not so bad in making those brass stamps.