View Full Version : Cutting Aluminium With A Cheapo 3020 CNC

28-04-2014, 08:31 AM
Hi Guys,

I have read a bunch of threads on here, but think most of them apply to proper machines, not ones like my little toy. This (http://www.ebay.co.uk/itm/300936444652) is the machine I have if you need more info.

Here is the spindle info...

Spindle motor: spindle motor with direct current(200w)
Cutting tool-holder: ER11/3.175mm
Spindle speed: 300~8000RPM/MIN (PWM stepless speed regulating)
Spindle precision :radial beat acuities 0.03 mm

Very basic as you can see, but for milling PCBs it works great.

I have the need to cut some 2mm Aluminium plate and as this is probably going to be a one off, don't want to invest in upgrading the machine.

Any suggestions on what type of cutters, DOC, speed etc would be greatly appreciated.



28-04-2014, 10:32 AM
I'd go with 3mm Single Fute Spiral Cutters like these -

Carbide Engraving CNC Router Bits Single Flute Spiral Endmill Cutting Tool 1/8" | eBay (http://www.ebay.co.uk/itm/291049116021?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)

I've been using one of these cutters to profile small plates from .7mm Titanium plate and it's working very well, I've also found that they're very easy to resharpen on a fine grinding wheel as the geometry of the single flute is not complex.
Stick your work down to a spoil board/plate with strong double sided tape and use a Profiling Feature which ramps down into the work a set depth per circuit of the profile.
Try with a .2mm per pass ramp down into the work and if everything's smooth at that increase your feed until it starts to sound a little less smooth then back off a tad.
For feeds & Speeds download the free trial of HSM Advisor here -

Advanced CNC Speed And Feed Calculator - HSMAdvisor (http://hsmadvisor.com/)

It's nothing short of toptastic, it gives me a good start point every time and Mach3's feed override allows me to creep up to the edge of the envelope for my job, tooling and setup

29-04-2014, 08:24 AM
Thanks for the reply.

I noticed that it doesn't list Aluminium as a suitable material for those bits though.

As there seems to be a limited range of bits with a 3.175mm shank, I wondered if it was worth getting another size collet?



29-04-2014, 09:21 AM
Someone mentioned this site recently, they have a great range of cutters etc.
Search Results Associated Production Tools (http://www.shop-apt.co.uk/search/for/er11/)

Edit: It was 'Washout' here; http://www.mycncuk.com/forums/tool-tooling-technology/7439-aluminium-cutting-2.html#post57533 Thanks by the way Washout I'll be getting some from there myself.

30-04-2014, 12:13 AM
If it is only for very occasional use (cutting ally) Just take it very steady and go for it. I sometimes cut ally with my converted pcb machine and I can only use 1/8" shank cutters. I use 1/8" 2flute carbide spiral down cutters as they are the largest cutters I have.
I limit the DOC to 0.5mm, spindle speed about 18k rpm and feed speed about 400mm/min. I use WD40 as cutting fluid applied in small doses so as not to make much mess. After a couple of passes the fluid tends to just stay in the "trench". I do not produce chips as such, more like ally filings which just swim about in the trench. I know that the afficionados will frown upon this method, but it does allow me to cut ally if I wish. G.

05-05-2014, 09:59 AM
Thanks for the help guys, I managed to do it by taking it slow. I don't think this machine will cope with some of the speeds suggested, but it did it ok in 0.2mm steps at 100mm/min.