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DuffelBuffelWuffel
07-09-2015, 10:59 PM
Hello,

My name Is Ruffel and I have a FS4MG epoxy granite milling machine from Germany.
While the machine is perfect, my skills aren't ... The goal of this topic is to learn how to cut alu. on my machine without issues.
And I will be posting my journey here. I'm not exactly sure of this is the right category ... but yeah :)

Setup:
- FS4MG milling machine
- China 2.2KW 12-24K RPM spindle (mechatron equivalent) with parker VFD
- Leadshine hybrid stepper setup on 3 axis
- Eding CNC (USBCNC) 3axis
- aquarium pump for my coolant

Problem:
The problem is that Alu likes to stick to my end-mills really fast. I have tried manual lubrication, different alu. composition , different cutting settings , different endmills.
This is all without any cooling or air blast.

So..
I have bought a few things to make alu cutting a bit better and generally making my life easier:

- 280 l/min Hailea ACO piston 500 pomp for blowing chips and mist
- Vertex VA-4 because my VK-4 can only open 62mm ...
- Haimer 3d taster
- VHM 6mm 1F endmill , VHM 8mm 1F endmill. I already have a bunch of 6mm VHM endmills here.
- 2x china mist setup that is sold on ebay (~10$). This + pump + ethanol as "mist" -> seems to work for Datron
- Some AlCuMgPb (2007) Alu for doing some test milling. This stuff is supposedly one of the easiest Alu comp to mill. I have also some 5083 and some 6061 / 6082 laying around (although not marked , second hand).

I had already planned to buy the Haimer and the VA-4 , so these are not specific for this problem.

Previous experiments

I have using G-wizard to check all my speeds and feeds. According to it I should have been fine. But I't kinda can't estimate if gumming is going to happen.
My machine is stable enough to do feeds of about 1-3 m /min in 3d motion with no problems.

To be honest due to work and other experiments I have not used it to much in the last few months. Now I have dedicated time for this project and I really want to do some cool projects.

The last experiment was with the following settings:
6mm 2F VHM (new), 24K S , 10mm depth , 0.595 mm stopover , feed from 1000-6000 (kinda tried everything) occasional lamp oil lube , no air blast. After about 30 seconds to 1 minute of time before the endmill would clough up again. Other than that is worked perfectly, nice surface finish and fast milling. The chips were about 10 mm long with a small spiral in it and they were not warm. The endmill got hot because of the rubbing.

Alu was from the 5083 or 6061 or 6082 series (yeah... second hand )

New plan
I'm waiting for all the parts to arrive. First I will set up the mist / chip blasting system up. I think this will already help enormously if not solve the whole problem.
Set up the new vice and dial it out with the Haimer. To start I will probably do some face milling with a 6mm 2F VHM (new) that I already have laying around. This will be probably on the "new' 2007 Alu that I got.
When this goes well than I will try some pocketing, slotting and contouring of this piece.

If that all works out fine than I'm gonna try some milling on my "old" Alu (5083 / 6061 / 6082) and see if that works out. I think this should not be an issue with the misting system.

In the end I'll try out my new "expensive" 6 mm and 8mm 1F VHF endmills and see if that works out. Datron seems to have good luck with them ... so why not me ? :P


So... Any tips are appreciated , this might be a bit of a weird topic ... so I'll say sorry beforehand.

Thanks,
Ruffel

DuffelBuffelWuffel
08-09-2015, 01:57 PM
The first part cam in , the Hailea 500 pump. it is a bit bigger than I had imagined.
But being this big it also gives some confidence that it will work good:
http://www.mycncuk.com/attachment.php?attachmentid=16010&stc=1

DuffelBuffelWuffel
08-09-2015, 02:03 PM
It is almost as high as two toiled paper roils stacked.

I'm currently thinking on how I'm gonna run my air lines.
13mm ID from pump to the mill head and split it there to 2x6mm ID or do it directly at the pump....
not sure yet , do you guys have tips ?
(system won't let me edit the post above)

Boyan Silyavski
08-09-2015, 04:15 PM
What are you trying to do, a mist system? you need an reservoir under pressure and air coolant mix valve and 1mm nozzle, system pressure 2.5 bar. Datron uses direct pressure liquid pump and 0.4mm? nozzles or sth like that.


aluminum best is done with 2 stage process:
-roughing
-finishing

1 flute or 2 flute, up to three, depends on geometry and slot cut or no.

6mm bit seems to be the best for home use

try something conservative and speed it up / the feed rate/ and or increase the depth pass:
12000RPM, 1.5mm pass depth , 800-900mm/min


kerosene works best, or just mist spray proper coolant mixture


you will do nothing without a coolant, just brake bits


my test show that 4mm tubing/2.5mm inside/ is ok, so it does not matter in your case

DuffelBuffelWuffel
08-09-2015, 04:28 PM
Yes I'm doing an mist system. I ordered two of these:
http://www.mycncuk.com/attachment.php?attachmentid=16018&stc=1
http://www.ebay.co.uk/itm/Mist-Coolant-Lubrication-Spray-System-for-CNC-Lathe-Milling-Drill-Grind-Machine-/252043904329?



I did some googling and other people seem to have good luck with these aquarium air pumps. Most of them use the 80 l/min models but recommended going 120l/min +.
So I just got the biggest one. A compressor would be just to loud for my situation. And the paintbrush one's seem to have a hard time to keep up with the airflow.

If it does not work out than I will just return it in 14 days and get my money back. In that case a paintbrush / real compressor will be the alternative.
People who use compressors seem to be running these nozzles <1 bar so I think I'm alright.

As a liquid I'm testing lamp oil or ethanol , these both should work out fine.

The 280 l/min might be a bit much for my two little misting units , so it is possible that I need to add 2-3 more or just some copper to get some more volume trough it.

here is somebody running a 65-120l/min system:
https://www.youtube.com/watch?v=_X9TPBCdGyo

Thank you for the recommendation. I will defiantly try it.

JAZZCNC
08-09-2015, 11:30 PM
After about 30 seconds to 1 minute of time before the endmill would clough up again. Other than that is worked perfectly, nice surface finish and fast milling. The chips were about 10 mm long with a small spiral in it and they were not warm. The endmill got hot because of the rubbing.

The chips being cold is not a good thing. They should be so hot they hurt when they hit your skin and the part should be cool.

With a 6mm tool and 10mm doc with 0.6mm Stepover is a fair removal rate so will need plenty of chip clearing so if you haven't got enough air or coolant then you'll be recutting chips and why cutters are gumming up.

Buy some serrated edge 3 flute carbide roughing cutters and you'll get much better removal rates.
With 8mm 3 flute roughing tool I can cut 15mm DOC ground plate with trochoidal tool path with upto 1.5mm stepover at 2500m/min dry no lube just air, lots of air. With Air mist I can push harder.

Finish with full depth 0.2mm pass using 2 flute HSSE cutter with air/lube and get a mirror finish.

Air is a minimum must have when cutting ali and plenty of it. Low fog mister is perfect provided there's enough air to clear chips.

Clive S
09-09-2015, 08:18 AM
Yes I'm doing an mist system. I ordered two of these: These look like the same at a third of the price.

http://www.banggood.com/Mist-Coolant-Mist-Lubrication-System-Unit-For-CNC-Lathe-Milling-Drill-Machine-p-979642.html

DuffelBuffelWuffel
09-09-2015, 08:51 AM
Yeah I know. I just wanted to have it before the weekend.

Boyan Silyavski
09-09-2015, 11:18 AM
The chips being cold is not a good thing. They should be so hot they hurt when they hit your skin and the part should be cool...
my legs are witness to that ...

Welcome back Dean!



These look like the same at a third of the price.

http://www.banggood.com/Mist-Coolant-Mist-Lubrication-System-Unit-For-CNC-Lathe-Milling-Drill-Machine-p-979642.html

Thanks Clive,
i have browsed and browsed but have not seen these


Yeah I know. I just wanted to have it before the weekend.

Then make something provisional. By the way a quiet airbrush compressor like mine 17l/min (http://www.vpiera.com/en/producte:Cos/1/graphic-design/airbrushing/compressor/compresor-silent-dalbe-dr/6232) is enough when using the proper nozzle and making fine mist.

Much prefer mixing air with coolant as a cup of coolant could provide cutting all day long


here is my system:

On first video you could see the system and the damned mist when too much flow. Watch HD quality ant see how the light shows the mist in the air. What i am saying is it should not be like that cause after 5 min you could hardly breathe in the workshop.



https://www.youtube.com/watch?v=6wFqyHL5fcY



On second video is properly tuned and spraying just the minimum. The air when thin is so strong that will blow crap from 20mm cutter from 20cm distance and clean properly before the cut . Plus no problem breathing in the workshop




https://www.youtube.com/watch?v=c07M_-QUVUE

JAZZCNC
09-09-2015, 11:33 AM
Welcome back Dean!

I Never left Boyan.! . . Was more unjust put in the naughty corner.!

The other voice in that video sounds like a Yorkshire Man.?

Boyan Silyavski
09-09-2015, 04:11 PM
I Never left Boyan.! . . Was more unjust put in the naughty corner.!

The other voice in that video sounds like a Yorkshire Man.?

Its my friend Jeff Potter. he happens to live nearby, we became friends from here, the forum. We are in his workshop making my Z. No idea where is he from exactly. On all pictures on Facebook he wears a red white vertical stripes T shirt, so he should be from somewhere there, i dont know the team name though...

DuffelBuffelWuffel
09-09-2015, 06:13 PM
I replaced the aquarium air pump with AS196 compressor with one paint/air gun.
When this all works out than I will make me a decent "fogbuster" setup.

The single flute VHM cutters also came in and they look really mean:
http://www.mycncuk.com/attachment.php?attachmentid=16022&stc=1
6 and 8mm

Around Friday / Saturday I'm able to start experimenting.
Again than you for all the help!

DuffelBuffelWuffel
13-09-2015, 02:47 AM
Quick update.

Vertex VA-4 vice came in and I must say It very good for the price. Nice and heavy (~20Kg) and it allows larger work-pieces to be clamped because of the movable jaws.

I also installed inductive sensors on all axis to home the machine. The step loss is 0-1 and in the rare occasion 2. 1 step loss is about 0.0025mm and that is probably because my sensor holder is a bit wonky and the sensor probably has some error to. I have hybrid steppers with encoder so there should be none to very little step loss. I haven't tested it with a dial indicator yet...

The Haimer 3d probe is a nice piece of kit. When I was getting it out of my ER tool holder It fell a few cm and the probe broke off. So I have ordered a new one and a spare.

The As196 compressor is a nice and quiet compressor. I would like some more volume. In a later stage I might hook up 2-3 of them to a 50-100L tank and get that up to 6 bar. This would be nice for non-cnc stuff.

Last but not least I received the china mist thing from ebay ... but I haven't had much luck with it.
There is no way to adjust the amount of coolant that gets in the nozzle. When you turn the air down and the coolant reservoir is higher than the nozzle you will get quite a stream of coolant coming out of the nozzle.

When the reservoir is just a bit higher or lower than the nozzle there will be no coolant coming out. Does not matter if the system is at 1, 2 or 6 bar. The airbrush pistol that came with the compressor does a much better job. It even has a ionizer pin inside of it. Might hack that up later ....

I would like a fogbuster ... but they are just so damm expensive. Haven't the Chinese copied it yet?

Now I just use 1 or two air blasts at the endmil.

Oh and I also found out how to do automatic tool height compensation with EdingCNC and a tool-setter. Sadly during my last test I entered the estimated tool length wrong. The tool went into the tool-setter and broke the limit switch inside... Damage 3$

Tomorrow I will do some milling with the machine. I will also make a short movie about it and post some pictures of my setup.

DuffelBuffelWuffel
14-09-2015, 07:12 PM
All went ... excellent to my surprise :)

All the feeds and speeds from gwizard work out fine , I had no mist on at the time , just a light (like blow light) air stream at 4 bar.

Video:
https://goo.gl/photos/3BqRiQLr8N396J7P6
This is about 1200mm feed, 12-15k rpm? and 2.5 mm deep . 7.9993 mm wide with a 8mm single flute cutter.

Video 2:
00:00 -> 20:00 is finishing the top at like 168 feed (gwizard) very light load. You can see the machine in the reflection of the material.
@23:00 it goes a bit deep ~10mm , 8mm 1F (conventional acc. Gwizard)
https://goo.gl/photos/tfS2MxWC95hTbb5t5
I changed the cam after that.

I like the 2F VHM cutters more than the single flute. The 2F allows me to go higher rpm and feed-rate (at least in Gwizard).

Finishing:

https://goo.gl/photos/UKZSaxefNBPmG6Xc8

Picture of machine:
https://goo.gl/photos/UgQrhXFBPk1CAceN6

https://goo.gl/photos/hCpUkn3ZG5RDuqREA

The AS196 is a bit low on air volume in my opinion. I would like a harder stream of air.
Adding a 25-50-100 liter external tank with an additional pressure regulator might do the trick.
So the compressor can turn at 4-6bar and filling the tank. The tank can provide 1-2 bar at a bit higher volume than regularly.

Due to the small tank (1.5l?) turning down the pressure regulator from 6 bar to 4 3 2 or 1 does not help to get the volume up.

The machining time is usually so short that a bit bigger tank should solve this problem.

Or I might get a timer and an solenoid that just pulses the air at a higher pressure every few seconds for a short period. Allowing the compressor to catch up and clearing the chips and cooling the bit better.

Anyway.. the machine and cutter works fine. I'm trying some higher feed-rates next weekend to "comply" with the HSM idea.