View Full Version : Milling Slots - Noob question
04-05-2016, 04:54 PM
For my first aluminum job, I need to mill a series of 6mm wide slots, 10mm deep in aluminum. I have a decent 6mm, 1 flute end mill. Looking at various Utube articles, most people have an air blast system of some kind aimed at the endmill to keep the slot clear. Can anyone recommend such a system I can fit?
If I have an air blast system fitted, do I also need a coolant feed? It would be much cleaner if dry milling was OK.
Can the air blast be replaced by a vacuum device instead?
04-05-2016, 08:08 PM
If the slot dimension is critical you might find it a little over size, if I needed a slot bang on 6mm I'd use a 5mm cutter.
The single flute carbide cutters are magnificent, I've done a lot of aluminium profiling with one using just air, with light cuts it keeps the cutter cool enough, I use a compressor and regulate the pressure to give the flow I need to clear the chips.
To direct the air onto the work I use a length of clip-together coolant tube with a canula needle epoxied into the end of the nozzle, I ground the end of the needle off square for safety.
I have a drip feed to introduce lubricant into the air flow which helps with aluminium and is essential with stainless ;-)
Vacuum will need a shoe over the work to lift chips out of a deep slot, if you had a 100% hard vacuum then you still only have atmospheric pressure working for you, about 14psi.
05-05-2016, 12:45 PM
I use a mister like this: http://www.ebay.com/itm/Metal-Cutting-Engraving-Machine-Mist-Coolant-Lubrication-Cooling-Spray-System-/252314226636?hash=item3abf198fcc:g:ttQAAOSwwpdW3~E X
And I also prefer using 1-flute cutters, they are phenomenal in Alu. For coolant I use what I have easy access to; alchohol. You adjust it so there is only a light spray, and the chips will fly out and not stick to the walls. Easy cleaning afterwards as it vapors. I have a fan that pulls it out of the room, but for short jobs its gonna be ok without.
Are you using a CNC or is this a manual job?
05-05-2016, 03:37 PM
Hi Nick & sinnsvak,
Thanks for the advice. I found a post where one guy used a 70 litre/min air pump with a flexable pipe and brass nozzle. He also found this to cool the work sufficiently on its' own. So, I've just ordered a similar pump and the mister from eBay.
This weekend I am going to build a complete enclosure for the 6040 with a pipe to fit to my dust extractor (a built in vacuum cleaner). That way, when I mill MDF, all the dust remains contained. That should solve all the environment issues :)
I think I may have damaged my new sorotec end mill by not clearing the chips well enough last time I used it. The cutting edge looks a bit 'nicked'. As for the slots, no, 6mm is not essential. As I have a 6mm end mill I planned on simply running the tool back and forth as a series of rows to create the slots. When all this is sorted, I'll go back to milling out that 40mm thick block of aluminium.
Good point about sucking out the chips. I'll stick with your solution to blow the chips away then hoover out the chips after the job is finished. As for using alchohol for extra cooling which then evaporates, brilliant idea!
06-05-2016, 07:21 AM
I use a 140 litre/min air pump made for ponds and a 1/4 locline kit with i think a 3mm nozzle. its works pretty well and load quieter then having my compressor running all the time.
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