Aussie Mike's machine shop

[Aussie Mike]

Uploaded part 2 of the handbrake machining project.

[ame]https://www.youtube.com/watch?v=Y6J8wXg2BRI[/ame]

Cheers

[Aussie Mike]

If anyone is interested in a great milling machine my old BM-30A manual mill is on the market.

Hafco BM30A Milling Machine in VIC | eBay

Cheers

[Aussie Mike]

I love it when goodies turn up in the post.

These are solid carbide end mills in 10mm, 8mm and 6mm diameters

The plain silver ones with the high helix are a 3 flute design with geometry specifically for aluminium. The flutes are also set so you can plunge cut down like a drill.

There are 2 Ball nosed 2 flute end mills. These are great for machining a pocket with a nice radius on the corner. The other two end mills are 4 flute and designed for machining steel and harder materials.

The darker colored coating on some of them is an Aluminum Titanium Nitride (ALTiN) coating. It's a very abrasion resistant coating which makes them ideal for harder steels like 4140



Using this CNC mill is changing my mindset around tooling as I work more with it. Previously I would have a selection of different sized cutters from about 3mm up to 20mm or more. Mainly for getting the inside corner radius I want on a particular part. With the CNC machine you can program whatever radius you want so that’s meant I’ve been doing most of my milling with 8mm and 10mm end mills. So now I'm collecting a variety of styles and geometries around these sizes that should be able to do most jobs I need.

Cheers

[renovationinnov]

sorry to be ' dumb' but what are the 3rd from the left & 4th from the right
they are different so what milling do they do different to the others
as I don't know I'm a chippy
rob

[Aussie Mike]

Originally Posted by renovationinnov

sorry to be ' dumb' but what are the 3rd from the left & 4th from the right
they are different so what milling do they do different to the others
as I don't know I'm a chippy
rob

Not a dumb question at all Rob. As a chippy just think of end mills as fancy precision ground router bits. The materials and geometry used are just to suit metals rather than wood and they are run at much slower speeds than a router bit. I'm typically running around 2000 RPM instead of 20,000 for a router bit.

These end mills are also ground from solid pieces of super hard Tungsten carbide which is the material braised onto the tips of your wood working circular saw or masonry drill bits. Most are usually made from tool steel which is the same as most regular drill bits

The odd looking end mills you referred to are the ball nosed type. Instead of having a square shoulder and cutting a square slot or rabbet they cut a slot with a radius bottom. This pic comparing a square and ball nose might make it a bit more obvious



End mills unlike drill bits cut on both the end and the side of the tool. They typically have from 2 to 5 flutes. Generally the harder the material the more flutes you want to spread the load across. Higher numbers of flutes usually means a lot stronger tool for the loads applied to it. You want the tool cutting and not flexing and rubbing across the surface.

Here's a 2 flute ball nose end mill on the left, A 3 flute aluminium cut in the middle and a 4 flute conventional on the right.



The aluminium cut endmill has different geometry to suit the softer material. It's designed to run at higher speeds and the higher helix is better at clearing chips away from the cut. One of the issues you have with aluminium is chips getting dragged back into the cut and messing up the surface finish or welding themselves to the tool. The higher helix also means there is more cutting edge in contact with the material which reduces chatter. Before one edge is leaving the cut the next one is starting. Chatter is a harmonic vibration that causes the tool to flex and bounce over the surface which can lead to tool breakages and also leaves a poor surface finish.

Looking at the close up of this aluminum cut end mill you can see how the ends of the 3 flutes have been ground to cut the bottom of the slot. If you look close you will see the left side flute has been ground so the cutting edge extends right to the middle of the cutting circle. This is what allows it to plunge cut. The 3 edges cover the whole area of the circle where most 4 and 5 flute end mills will have a hollow in the middle where it won't cut. They need to start at an edge or a pilot hole to get going.



Sorry to bore you all with this but I find the design and geometry of these tools quite interesting. Especially the developments in recent years.

Cheers

[750hp]

Great stuff Mike. I'd love to go and do a TAFE course on metalwork and fabrication, but I'd be annoyed if the teacher didn't have your passion!

[Rog246]

What a great explanation of how these things work and why. Understanding the why's and therefores helps making sense of this, to me anyway.
Thanks Mike

[SVO 050]

Craig,
I work for TAFESA as a maintenance fitter, you will find that the country lecturers have a great attitude and passion for their work as they have to cover all aspects of the job from visiting employers to counselling students.
If you choose to complete a night class you will find the lecturers go out of their way to pass on their skills and experience.
Just my observations from in side the organisations.
Cheers
SVO

[Aussie Mike]

I had good experience with TAFE. I did a MIG welding course many years ago and it was brilliant.

I'm a trainer by profession now so that's why I probably feel the need to explain things LOL!

Cheers

[renovationinnov]

thanks mike that was my 'LEARNT SOME THING TO DAY '
rob

[Rog246]

[QUOTE

I'm a trainer by profession now so that's why I probably feel the need to explain things LOL!

Cheers[/quote]

Does this mean you're well trained then Mike?

[Aussie Mike]

Originally Posted by Rog246

Does this mean you're well trained then Mike?

No I just bluff my way through. This bloke is my hero.

[ame]https://www.youtube.com/watch?v=Ac7G7xOG2Ag[/ame]

Cheers

[Cobra72]

Hahaha.....that is gold!

[Rog246]

MATE........he's not only a hero.....

Hes a friggin' legend !!


ROFLMFAO

[gjkrv8]

What no phoofa valve? I can't see how it would work. :-)

[Bernica]

I saved that one. Thanks Mike. He's now my hero too!
I can totally relate.

[Gav]

What's so funny about that?
I think that clip was very informative.

[SVO 050]

Brilliant Mike, that,s a gem.
Now that you have revealed your vocation it explains your posts , now I know why you enjoy educating the forum users..
Cheers
SVO

[Aussie Mike]

I've been collecting a few more bits of tooling for the new mill.

These turned up in the post today. They are corner rounding bits. I've always wanted a set and with the CNC they are so much easier to use as you can just add the tool offset into the program.



For those who don't now what they are, they are designed to cut a nice rounded outside edge. Like the ball nose end mill cuts a rounded inside edge. This set has a variety of radius cutters from 1mm to 8mm.

Should be able to add some nice finishing details to parts with them.

Got a few more goodies in the post but they haven't turned up yet.

Cheers

[Aussie Mike]

Here's a little machining job idea I've been working on. I've designed a work light for the milling machine that attaches to the end of the quill. It uses an LED Halo ring like they use in BMW headlights. The idea is the the light shines around the whole cutter and casts no shadows so you can see the cut easier.

The normal work light shining in from the side can cast shadows making it hard to see sometimes when you are trying to machine up to a scribe line etc.

The Aluminum housing attaches to the end of the quill with some strong neodymium magnets. This lets you quickly un-clip it for extra clearance. 12V DC connects to it via a curly cord that stretches and retracts with the quill.



It was a fun machining project.

Cheers