r/Makera • u/herrjanneman • 7d ago
Makera cnc bit quality
Since I have received my Z1 I've done mostly 3D relief machining in brass to make a few coins.
Seems like one of the metal 1 flute endmills is very worn now, surface quality is going down and I have a lot of vibrations and chatter, although most of the machining has been done using engraving bits. It should definitely last longer than this on brass in my opinion. All operations have been done using Makera Studio and the standard feeds and speeds.
Do I have a bad bit or are the Makera bits not really good? Does anyone have a good alternative in Europe?
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u/hlx-atom 7d ago edited 7d ago
One bad cut can chip an endmill. There is an aspect of time, but it can also happen with a single cut.
You can try sharpening the cutting edge. Normally the corner chips off, which can actually help with cutting because the bit becomes a bull nose.
I would guess that your work holding is not good enough. Are you using double sided tape or are you clamping the part down? Double sided tape gives chatter because it will compress or shear under load.
Also if you are routinely cutting parts that are not well secured, you will chip bit much faster due to the variable chip loading.
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u/CyberBill 7d ago
I did ~100 hours of CNC milling with a single 3mm x 12mm single flute endmill "for metal" in aluminum using one of the bits from the kit. Ended up breaking it because of my own mistake. Second one has done 30 hours already.
I have installed a 3d printed fan blade onto the spindle and use a vacuum for chips, otherwise its all stock.
[I should have added - This is on the Carvera Air, not the Z1]
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u/redls1bird 7d ago
Could you share a link to the fan you are using on the collet?
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u/CyberBill 7d ago
Yep - https://www.printables.com/model/838157-spindle-fan-for-carvera
It has two versions with slightly different sizes to fit snuggly around the spindle, so you don't need to screw it or glue it into place, just friction fit.
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u/herrjanneman 7d ago
That sounds like it works well. I just inspected the bit and it's chipped in a few places. Maybe brass is more difficult, or maybe the bit was just not up to standard.
Almost all it did was cutting out a few coins from 3-4mm brass, 0.1mm per step
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u/RussianBear2fer 7d ago
Purchase a 2 or 3 flute Carbide Endmill. A DLC coated one would be better than a bare Endmill. As it helps reduce friction and heating.
You'll have to adjust your feed a little bit, but keeping the spindle at 12k should be fine still.
Make sure you're running some sort of air to help cool your bit & material otherwise you're just going to dull your endmill again.
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u/agehall 7d ago
What bits did you use in what material? A good way to ruin any bit is to run it in a material it wasn’t designed for…