Dry milling aluminum in general and 5154 in the hobby

[sovcams_back]

Hello, I'm just starting out in the hobby machining. I've got two micro machines - a lathe and a mill, both manual Taigs. I'm not a native English speaker but I'll try to do my best.

I've tried so far to collect as much information as possible on the starting out in the hobby machining and I got overwhelmed with many conflicting ideas.
I see that on YT many manual machinists with small mills like Taig, Sherline and Sieg don't use any coolant when milling aluminum. Mostly they do surface milling like squaring blocks, making some steps on the sides and taking material out in the middle of the top. Normally large diameter milling tools are used for that.
On the other hand in the CNC aluminum machining with lots of pocket and groove milling as I understand the cooling is a must.

So is manual milling of aluminum with large diameter tools and slower spindle speeds normally less demanding in terms of cooling?

The second question I have is specifically on the 5154 aluminum alloy. I just happen to have couple of 1/2" thick plates of approx 14x10" size, a few thicker but smaller in size plates of the same 5154 and quite a lot of different round 5154 stock ranging from 1/2" to 3" in diameter and various lengths.
I'm not restricted to building model engines in my future machining hobby plans but anyway - is the 5154 alloy of any use in the model engines field at all?
I know that 5154 is of relatively low hardness as compared to 6061 for instance and having high plasticity it will definitely present some difficulties in machining without coolant which rhymes well with the first part of my question.

 

[kuhncw]

Hi,

Your English is very good. You should be able to machine aluminum with no coolant and have no problems. My experience is with 6061 and 7075. I've not machined 5154. Maybe others on the forum have experience with 5154.

Your Taig machines will do a fine job for you

Welcome to the forum and good luck.

Regards,

Chuck

 

[Lloyd-ss]

I don't think you will need any coolant with your machines, but you will definitely need some sort of lubricant, which you can apply with an artist's paint brush. Heat build-up won't be the issue, but chips welding to the tools is always a problem. More problem with the mill than the lathe, because the chips tend to clear themselves on the lathe, but not the mill. Just keep them cleaned out as you machine, using a small paint brush or similar.

If you get aluminum buildup on your tools, just clean them off with diamond lap or fine sharpening stone.

 

[timo_gross]

.. chips welding to the tools is always a problem. ...

I agree, recutting chips and built up are the enemies for reasonable dry milling.

For tapping i use some fluid it helps a lot.
I see that some cutters weld chips like crazy (I can leave the coated cutter in, it will do fine for the small cut, ... never does :-( ), others do not as much. Some coatings ("gold color" and others) have horrible build up with Al.
In doubt uncoated and polished. HSS endmills with a good finish might work reasonably well with Al, if you take it slow.
Special Al tools work better but are more expensive.
Try to remove chips. ( I think a small wet / dry vacuum is a good option for a small milling machine)

 

[minh-thanh]

Hi !
I have not machined 5154 . aluminum
In the past , my friend gave me some aluminum bars and plates ( he bought but never used ) , which is aluminum cast from aluminum scraps , it is actually much softer and more flexible than 5052 aluminum . When I cut cooling fins, thread... I usually use w20, w40 oil, the cutting tool is HSS .
I made 2 engines with that aluminum - With the connecting rod using brass bearing or 6061 Al connecting rod
Hope this helps

 

[danallen]

I use a water soluble oil at about 20:1 and apply it with an acid brush.

 

[Jasonb]

It's unlikely you are going to get things warm enough to need coolant to actually cool the work. Small amounts of coolant, cutting fluid, Kerosene or even WD 40 will help in stopping small amounts of material sticking to the tools cutting edge which in turn created heat and make snore stick. I just brush apply Kero when manual machining.

Also avoid coated tooling such as TiN and TiAIN which the metal will find it easier to stick to so use uncoated HSS or Carbide. Also worth getting aluminium specific cutters as they will remove the larger volume of ships quicker due to their high helix angles.

Lastly when doing things like slots they can fill with chips and cutting the chips will blunt the cutter and spoil the finish so remove them, without flood coolant to wash them away it is best to blow them away with a small compressed air line or failing that blow through a rubber tube but be careful getting close to the cutter

 

[sovcams_back]

Thanks much for all you replies! That definitely clears up things for me.

 

[mcostello]

Aluminum build up on cutting tools should be easily removed with a cut on a piece of steel. Another solution would be drain cleaner. (See what I did there?)

 

[packrat]

Your English is wonderful, like has been said WD-40 seems to work on manual milling of aluminum.
I have milled 6061-T6 with WD-40, if you wont to spend more money try TAP MAGIC for aluminum.

 

[SmithDoor]

Hello, I'm just starting out in the hobby machining. I've got two micro machines - a lathe and a mill, both manual Taigs. I'm not a native English speaker but I'll try to do my best.

I've tried so far to collect as much information as possible on the starting out in the hobby machining and I got overwhelmed with many conflicting ideas.
I see that on YT many manual machinists with small mills like Taig, Sherline and Sieg don't use any coolant when milling aluminum. Mostly they do surface milling like squaring blocks, making some steps on the sides and taking material out in the middle of the top. Normally large diameter milling tools are used for that.
On the other hand in the CNC aluminum machining with lots of pocket and groove milling as I understand the cooling is a must.

So is manual milling of aluminum with large diameter tools and slower spindle speeds normally less demanding in terms of cooling?

The second question I have is specifically on the 5154 aluminum alloy. I just happen to have couple of 1/2" thick plates of approx 14x10" size, a few thicker but smaller in size plates of the same 5154 and quite a lot of different round 5154 stock ranging from 1/2" to 3" in diameter and various lengths.
I'm not restricted to building model engines in my future machining hobby plans but anyway - is the 5154 alloy of any use in the model engines field at all?
I know that 5154 is of relatively low hardness as compared to 6061 for instance and having high plasticity it will definitely present some difficulties in machining without coolant which rhymes well with the first part of my question.

For cutting any aluminum I use clear thread cutting oil and a brush on to cutter.
You find trying to aluminum dry is hard to do.
I can cut steel dry but not aluminum.

Dave

 

[Bentwings]

I use a few drops of tap magic when I can . I used to just use saw cutting oil or lube it sours after while so I just had a little pre mixed in milk jug. Some time a small squirt bottle but the wet brush idea works ok I likes the acid brushes as I could use them everywhere . I can’t say I liked costed tools . I much preferred plain tools I had round smooth abrasive rubber Hines that unpolished the flutes with . Some where I go a round Arcansas white hone this thing put really sharp edges on high speed steel tools. You have to be careful of not putting too much rake angles on tools of they chip off then you have a problem wD40 used to be a popular item as the containers has nice spray pipes or nozzles but it’s not the best coolant or lube . It’s really not a lube but a water lifter works ok in the toilet too .
I agree, recutting chips and built up are the enemies for reasonable dry milling.

For tapping i use some fluid it helps a lot.
I see that some cutters weld chips like crazy (I can leave the coated cutter in, it will do fine for the small cut, ... never does :-( ), others do not as much. Some coatings ("gold color" and others) have horrible build up with Al.
In doubt uncoated and polished. HSS endmills with a good finish might work reasonably well with Al, if you take it slow.
Special Al tools work better but are more expensive.
Try to remove chips. ( I think a small wet / dry vacuum is a good option for a small milling machine)

 

[mcostello]

Kerosene works as do WD40, any type of penetrating oil as can be found in yard sales, flea markets, discount stores. The air is to keep the tool " dirty" as a clean and dry cutting edge will pick up Aluminum easily.

 

[bluejets]

Use mineral turps when machining, gives a mirror finish.
Use aluminium tap magic especially for standard soft aluminium tapping as it can be very "doughy" and small taps can break easily.
Normally use crc when drilling rough out work on the pedistal drill.

 

[Steamchick]

Hi Bluejest: I'm Not sure what "crc" is?
Ta,
K2
(A man of few words has used his thoughts well).

Found it: Just needed to search with the right semantics.

32686 | CRC Super Tapping Fluid II Thread Tapping Fluid 250 ml Aerosol | RS

uk.rs-online.com

THANKS!
K2

 

[packrat]

Yes..CRC makes spray lube and penetrants here is the US...

 

[Preston Engebretson]

We have used Olive Oil almost exclusively when cutting Aluminum...nice smell, and easy to get.

The finish if the tools are sharp is like a mirror...

Regards,

Preston

 

[JohnBDownunder]

We have used Olive Oil almost exclusively when cutting Aluminum...nice smell, and easy to get.

The finish if the tools are sharp is like a mirror...

Regards,

Preston

Interesting to me as I have made up a batch of "Angel's Breath" mentioned on a forum yonks ago. It consists of 1/3 Olive Oil, 1/3 White Spirit and 1/3 Turpentine. Fairly sure the turpentine mentioned is supposed to be the pure stuff artists use.Not mineral turps.
Here in OZ I got some Eucalyptus Turpentine from one of our big box stores.The other two ingredients I already had.
Works for me, also smells ok. A friend of mine, I am 99% sure has shifted to neat Olive oil after trying the above.
Guess like lost of stuff in hobby shops it is what works for your way of chewing metal.
Regards,
John B

 

[Jasonb]

I would have thought pure olive oil a bit thick and sticky and likely to stop the swarf being thrown/blown away but thinning with turps etc would just make it into a much lighter oil so should be fine.

 

[giel]

for aluminum use a LITTLE spiritus (called this way in the Netherlands) it is de naturated alcohol .

keep fire extinguisher or a fire blanket within reach.

using this for 5 years i NEVER had fire but it could possibly ignite (oil can to easy especially when misted)

use a few drops or a light squirt every once..
helps lubrication and prevents sticking of chips and will stick them together a little bit (prevent flying around) when machining and wait a few minutes and it will evaporate and you can vacuum everything away..

little note keep your workplace ventilated!

cutting oil on an open machine will give TOXIC fumes!!! olive oil i don't know..

closed machines with cutting oil (flood cooling) always are mandatory to have filter units on them to prevent operator cancer and lung problems.

big studies have been done on this part and proven health risks!!

also goes for mist cooling,also a big no-go with cutting fluid/oil
(Dutch health code) don't know how the rest of the world is regulated..