Thread: Cutting aluminium sheet

what about aluminium blade in a circular saw

Tried the suggestions from everybody. I am now down two more carbide bits.

The Aluminium just seems to be too soft. It clogs up the cutter and then breaks the shaft of the cutter. It is 5005 aluminium sheet. I think I would do better with some 5083 or 5086. Thoughts on that anybody?

Russell

Lifting doesn't seem to be the main problem, it is just galling (in many senses of the word).

I had an air jet directed at the cut to blow away any particles, liberally applied kerosene that smoked away as the cutter went through it, DOC 0.5mm, feed 1600mm revs 19000. I tried it with an end mill and also with ball nose. The end mill seemed to do a better job than the ball end until it clogged on the tip of the cutter.

It all does a great job until it breaks.

Bob
found this info I think it explain what going on...
http://www.suppliersonline.com/prope...05.asp#General

Machinability The machinability is generally poor, especially in the soft temper conditions. However it can be machined, but with more difficulty than many of the aluminum alloys. Machining in the harder tempers, such as H34, H38, is better than in the soft temper condition.

http://www.australwright.com.au/data...ium%205005.pdf
Machinability 5005 is readily machinable by conventional methods. It should be machined at high speed with copious lubrication to avoid thermal distortion of the workpiece. Sharp tools are essential. High speed steel or tungsten carbide may be used. Cuts should be deep and continuous, with high cutting speeds. Woodworking machinery may be suitable for short runs.


You might be best using a high speed steel as this can be sharper the carbide and you will need flood coolant
You can use corelight instead of mdf it is water proof on your cnc if you are willing to go that far
http://www.nover.com.au/Public/Broch...april-2012.pdf

Laser cutting would work.

Hope this helps

Russell

Originally Posted by Bob Willson

Yeah right. I make a machine that costs heaps of money, takes a year to make and is accurate to 0.0005 mm and it should do the job as easy as - so that I can use a jig saw for complicated jobs..

Pity it doesn't work and you need to ask advice then

Bob,
PM sent.
Cheers
Kim

Hi Bob
I regularly cut 2mm ali (don't know what grade, I purchase a full sheet from an ali supplier so probably not a good machining grade... some sort of rolled grade).

It may not help in your project, but I use .5mm carbide V-bits, usually at 22 degrees and 350mm/minute feed rate, 25mm/minute plunge speed and .5mm cut depth.
Spindle motor is normally at 24k RPM and I have (more thanks to good luck than good thinking) a 10mm ali table so it's all water proof. I use straight water pumped from one of those el-cheapo garden weed sprayers with the spray tip cut off and replaced with a bit of air hose to point the water stream which recycles back to a bucket under the table. A pain when it empties, but effective until I get a pump.

The biggest problem I've found with ali is keeping the tool path cleaned out. My water supply literally hoses out the swarf and away from the job. It has the added bonus of lubricating the tool and keeping things cool and this is the only real success I've had with cutting ali.

Maybe it might help if you do a rough-cut with a v-bit, then a final cut using an endmill if you don't want the beveled edge?

Hope this helps

Hi Bob

I think your RPM is way too high. Granted I was cutting 6061 T6 but 800mm/min and 8-10,000 rpm with a 0.5mm DOC worked well for me ... using wd40 or diesel as lube in my case and lots of directed air to clear the swarf. I also always climb cut
As soon as it starts to gall you have to stop and clear the cutter... it won't get better as you have experienced and will just result in a snapped tool.

Good luck.

BTW the sound it makes as it cuts is always a good indicator of how well or poorly the cutter is performing.

BTW I'm far from an expert but your next step might be to get coated, high helix cutters specifically made for alloy.

Hi Malibu
Thanks for your helpful reply. The idea of using a V bit had not occurred to me. it may work well, It is something that I should be able to try without breaking another bit.

Mike
Several others have also told me that my revs are set far too high. I am waiting for some new 6mm bits, but in the interim I may try Malibu's suggestion above and also try a 5mm end mill to then clean up the cut. I also have a can of WD40 equivalent, so I may try that at the same time and also continue with the air compressor to blow the swarf clear of the cut.
6061 T6 is a structural grade of aluminium and is a fair bit better for machining than the 5005

Thought I would post a bit more as per Bob's suggestion Like most people I belong to a couple of forums, the main one being Joe's 4x4 Hybrid, and the topics of cutting aluminium come up regularly. There are two trains of thought, one being slow and steady the other being the exact opposite. People from both camps have had great success so I guess what ever works for you. The most important thing to me is the right tool for the job. I've used only one brand of endmill from Destiny Tools the Viper aluminium cutter and, as I said in an earlier post, I'm far from being an expert but must have hit the sweet spot straight off. I bought four of the Viper endmills (2x 1/4" and 2x 1/8") expecting to break a couple but still have all four intact. I first went to the supplier and asked for feeds and speeds and his advise was as I am a novice go conservative with my cuts 10,000rpm and 50" (1270mm) per minute and I chose the .5mm cut depth (if this is conservative where does aggressive kick in). I used plenty of lube, kero in a shower spray bottle, and the chips came off smoking hot but the cutter was very cool to the touch. The aluminium I was cutting was from the 5000 series which is softer and much harder to cut then the 6000 series which is much harder and easier to cut. Hopefully my limited experience may help someone else.

Cheers all
Kim

Thanks Kim

So these are the bits you are using?

They are quite expensive individually, but if they do the job without breaking then they will work out considerably cheaper.

Bob try local, much quicker
I use sei carbide talk to shaun 02 47212000 or [email protected] he is very helpfully

Russell
Ask for my discount

Yes Bob, they are the ones. I've bought a number of endmills now from Oliver "The Drillman" they are good quality Kyocera brand made in USA (would have thought Japan or Korea) . I believe Oliver used to work for them as some sort of rep. Very knowledgeable and happy to answer questions. Slowly changing mine over to better quality bits.
Cheers
Kim

last night i was cutting 3mm aluminium with a 2mm bit , and went fine for 3 hours then snapped a bit , the next 3 bits only lasted 50mm . so i went too bed

this morning , it did the same to a 4th bit , but with a fresh cut i noticed its depth was changing , the bit was winding its self into the aluminium as it was cutting , making the cut deeper

while undoing i found that the collet was firm , and i didnt want to tighten it any more than it was ?????

oil in the collet ???
so the 5th bit i spun the bit's shank in some emery paper to scratch it up a little , and its going good now

Bob
I was reading through this last night
CNC Feeds and Speeds Cookbook and Tutorial
following a suggestion from Wheelie.
http://www.cnccookbook.com/CCGWizard.html
Might be worth your while to have a look at that calculator.
30 days free trial.
Cheers
Wolffie