I am trying to route .063 sheet aluminum to make signs. I have tried up cut, down cut, 2 flute, one flute, fast speed feed rate, slow speed feed rate and have not had good results. Can anyone help me?
Not sure what your issue is. but there have been several people here on the forum that list their success in this area.
Do a forum search and also you need to frame your issue for us to be able to help you.
Hello,
aluminum can be really difficult depending on the alloy - some are nice to machine, others a nightmare.
Aluminum gets soft when the temperature rises and at a certain point it starts sticking to the tool, clogs the flutes and finally breaks it.
- It may seem contrary at first but the harder and stronger the alloy the better to machine.
Hard alloys have a much lower tendency to get soft and stick to the tool. - The softer the worse - unfortunately sheet aluminum is usually soft as it should be bendable.
Try getting material advertised as “half hard” or “hard” - avoid material described as “annealed”. - Especially bad is anodized aluminum as it dulls the tool quickly and is soft, too.
About the tool:
- A tool for aluminum needs large flutes to get rid of the chips quickly without compressing and further heating them up.
This is best achieved with a low flute number so single flute is usually the best option for aluminum. - The cutting edge needs to be very sharp to cut with low forces and thereby avoid unnecessary heating.
- The flute should be as smooth as possible - preferably polished - to make it hard for the aluminum to stick to it.
This is a big weakness of many cheap tools - Even if the tool has only one flute, is sharp and polished it may not be designed for aluminum -> only use tools specifically designed for aluminum.
Other things:
- Cooling / greasing helps a lot -> just applying a bit of cutting oil to the surface with a sponge will make a big difference.
- Feeds and RPM are critical for aluminum milling - and unfortunately not really easy to get right without some trying.
You basically want small, nice looking chips: - If the machine produces dust increase feed or lower RPM
- If the chips are deformed lower feed or increase RPM
- Stop the machine after a few seconds and check if aluminum starts sticking to the tool -> if yes increase feedrate or lower RPM.
- Try trochoidal milling - this will work over a very large range of feed and RPM values.
Parameters( assuming you use Estlcam): - Feedrate as high as reasonably possible without shaking the machine too much
- RPM medium to high
- Cut at full depth at once - no need for multiple passes
- Trochoidal step width: 2-5%
It should create nice, needle like chips.
If they are deformed decrease trochoidal step widht a bit
If they are very fine you can increase it.
Christian
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Search this forum, there are more threads where people had trouble routing sheet aluminuim, There is one that makes helicopter instrument panels and succeeded in making proper cuts.
One of the problems of aluminum is that the std sheet metal you buy in DIY shops is maple sirup, it will stick to your tools and is very difficult to machine properly. If your hand saw is sticking to the material it will be difficult to cut. WD40 sometimes help but is not very healty.
Harder quality sheet metal is more difficult to find but a lot easier to cut.
Thanks all the feedback. The problem is what everyone described above. The aluminum is soft and I am getting what I would call tearout!
I was doing it in four passes. The aluminum was also getting really hot. I work at a sign shop and we have our letters water jetted. I thought I could use the router but I haven’t had any luck. It cuts the Lexan face great!
Also you want to cut fast but shallow. Like CRAZY shallow.
This will help prevent heat build up.
Also if you cut a channel a little wider than the bit that helps as well.
I have recently started to cut sheet aluminium (1mm) with a single full depth cut. Works quite well and takes a lot less time 
Feedrate 300mm/min for 2mm bit (1F) and RPM 10k.
For 3mm 3F I used 600mm/min.
Sheet was secured to the waste board using masking tape / super glue.
A light mist with denatured alcohol also used.
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I just got some CA glue and debonder to try my luck at small aluminum/brass pieces. I will post my findings. 
The debonder is new I have never used it before.
I use ca glue and masking for everything. No debonder needed.
It really is amazing the hold it has, and then the masking tape just peels right off when you’re finished
Do you have any issue with the adhesive bond of the tape softening and letting go with heat buildup in the work piece? Assuming there is heat build up…
I have never milled aluminum, so have no input as to heat related issues with masking tape adhesive.
I work at a sign shop and some of my routing is aluminum, I’ve had bad luck with the 3xxx grade aluminum but the 5052 grade is a dream to route (.080). Have also had better quality finish with climb milling. Trying to figure out what’s best for the softer 3xxx grade .080 sheeting, just routed 3 stop signs out of a sheet, the first 2 came out super rough, but the 3rd came out nice…
