Alternative to tabs for work holding? Double-sided tap? 0.5mm thick, long tabs?

[mattnedgus]

Thanks Washout - I might have to have a more in-depth search for sources of wider double sided for a try. Over on cnczone I posted the same question and dogsop suggested using blue tape to the back of the wood-to-be-cut and then gluing that to some hardboard with 3M spray adhesive which seems like a good idea too - it might be easier to remove than double sided too?

Cheers Jazz - It's wood I'm looking at the moment but I did wonder about that problem of breaking through. I've experienced the machine not quite cutting far enough through because of places where the natural flex in the wood has it standing slightly proud of the bed (unbeknownst to me at the time).

Out of curiosity what kind of feeds and speeds are you using to cut aluminium and brass? And do you use single flutes and coolant? I think it would push my machine too far but I wouldn't mind the experience of having a go.

[JAZZCNC]

Out of curiosity what kind of feeds and speeds are you using to cut aluminium and brass? And do you use single flutes and coolant? I think it would push my machine too far but I wouldn't mind the experience of having a go.

Oh so many variables that what works for me doesn't mean it will work for you. But I'll give a little idea.
Firstly I use method where I rough using 6 or 8mm 3 flute serated edge carbide roughing cutters so can push deep and hard. DOC will be anywhere between 3-8mm @ 1200-1700mm/min 15,000-20,000rpm.
Then I'll finish with polished 6mm Single flute full Depth of material.

Also I Often use Trochoidal toolpaths which cut mostly with full flute length or material depth and very fast.

In all cases I use Odourless mist or at least blown Air to remove chips and cooling.

Every machine is different so don't go by my or anyone else's settings without at least doing a few tests. Also don't be afraid to cut deep. One of the bigger mistakes in Ali or other materials is cutting too shallow and overheating the cutter. You want nice big chips that take the heat with them. If your making dust your doing it wrong.!!

[mattnedgus]

Also don't be afraid to cut deep. One of the bigger mistakes in Ali or other materials is cutting too shallow and overheating the cutter. You want nice big chips that take the heat with them. If your making dust your doing it wrong.!!

Thanks Jazz - it's interesting to get an idea of what others use. One of the problem-areas I've had is in my DOC's, feeds and speeds cutting baltic birch - I cut as deep as the cutter is wide (typically 6 and 8mm) with speeds of 13500RPM and feeds of 5000mm/min at the moment. I've been trying to get those chips nice and big while reducing some chatter and some instances where the cutter bites too deep and creates something similar to chatter but slightly deeper and further apart. It's frustrating trying to 'dial in' settings that work reliably to produce parts that need less finishing by hand! I'm considering rebuilding the Z axis to try and help eliminate some of the flex that must be present in the machine.