mystery artefacts...

[aegir71]

Hi, I am milling machining wax using 0.5 mm single flute up-cut and I keep getting these artefacts appearing in the surface of the wax (see pics) They are basically regular holes dug into the wax, the odd thing is that they only appear after type or features to the right (x+) of these feature and usually , but not always, at the top or bottom of these features. the wax is being cut at rates and speeds that does not melt it or I would blame clogging..

[Boyan Silyavski]

Looks like clogging. Do you use some kind of air blast while machining?

[aegir71]

Looks like clogging. Do you use some kind of air blast while machining?

Hi Boyan, i don't at the moment, would having a suction system work equally as well as I would like to recover the chips to recycle?

Does air blasting have a beneficial effect on the surface finish in wax to your knowledge?


thank you

[magicniner]

In addition to moving chips air will cool your work and tool to some extent.
Vacuum can never provide the chip clearance possible with compressed air, with vacuum you have a maximum (which you never achieve) of 1 atmosphere (Circa. 14psi) to play with, by using compressed air through blunted medical canula needles as nozzles you can get excellent results with relatively deep cuts & small tooling, the needles are easy to incorporate into standard snap-together coolant tube system nozzles, you can experiment with angle, position and number of nozzles to optimise chip clearance,

- Nick

[Boyan Silyavski]

I use 0.8mm nozzle in my setup / fog less/ and it will blow and clean chips from slotting with 20 mm cutter on the mill without any problem, so i assume 1 needle 0.5-0.8mm will be alright. Have not machined wax, but on any plastic its beneficial. I dont see any other reason for that marks, except some vibration on Z. If its clean around , when you finish the job you could vacuum the wax / i do that when machining brass. Air cools the tool quite a lot, much more than vacuum can do.

[aegir71]

Thanks guys, you have persuaded me to get myself a compressed air system as you have both described.
I'll have a look at the rigidity of the z axis too.

Onwards and upwards, thanks again for your help!