What is better? one bit , several passes or 2 bits, less passes?

CAD (Design) Software Carbide Create
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Hi!
Just a newby here… I am starting to carve with this incredible machine, and of course I need some help with my jobs… What its better for a good finish?? A 6 mm bit"slow" and 1mm deep cut, or a 6mm bit with “normal” speed and then a small bit ??
With the small bit, I need of course to make new toolpaths( Carbide Create) to carve only the parts I want to finish, and its not a very easy thingm but with a “normal” speed I see I am breaking the wood, instead of cutting it…

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I will start by saying I have no experience with CNCs. From being on this forum for a while, those who will help you often ask for details such as wood species, speeds (feed, etc.), type of 6mm bit, and so on - although many on this forum will be able to provide a ‘rule of thumb’ answer. If you provide as much information as possible, I am sure the responses will be even more helpful. I too am looking forward to learning from the answers.

1 Like
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well, you are rigth
for me this is “fast” ??
wood: pine
10.000 rpm
bit flat 6mm ( around 1/4)
DOC 3mm ( around 0.2)
Feed 5.000mm( 200 ipm)

and this will be with the small bit
10000 rpm
bit flat 3mm ( around 1/8)
DOC 1mm ( around 0.03)
Feed 1000mm( 40 ipm)

any ideas ??

I see that the 6mm bit breaks the wood, and I can see some “non cutting” zones, like the wood is… just being pushed apart, depends of the direction of the “grain”( it says grain??? )

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@Aitor - unfortunately, I have to say it depends. It depends on exactly what you are trying to carve. If you are doing a full 3D model, then a smaller bit with a smaller stepover will give you better final results. If you are doing a 2.5D cut, then the same bit, but slower will likely produce a better surface finish.

-Tom

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thanks… just a 2d sign… I will try then the slow …

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I’m struggling with feeds and speeds myself. I’m only 2 weeks in, and in general, I find that I’m pushing the machine too hard when I go with the “correct” feeds/speeds. I’ve started upping the RPMs and slowing the machine down to get better results. On 1/4" bits (6mm) I’ve been gong with less deep passes - especially for things like slots where the entire bit is engaged. I have a 1/8" (3mm) bit that seems to work better for profile/cut-out - it can cut 3/4" (19mm) material in a single pass.

I’m not an expert - just working through trial and error on a lot of scrap!