Milling cutter advice

[Maarten KipParticipant @maartenkip72631]

Hi to all,

I am relatively new to milling and was wondering if anyone could give me advice wich milling cutters are a good start for a beginner?

I have an Emco mill with ESX25 (ER) collets. Mostly i am planning to mill aluminium, brass, bronze, cast iron and mild steel.

What size is usefull and what geometry of the mill cutters? Finger, ball, 2 flute, 3 flute etc.

Will Weldon shafts fit into ESX25 (ER) collets?

Kind regards,

Maarten

[Maarten KipParticipant @maartenkip72631]

[Thor 🇳🇴Participant @thor]

Hi Maarten,

Weldon shaft will fit the ESX collets. I use both end-mills and slot-drills, I also have a few 3-flute and a couple of ball type, they don't get used often. Have a look here, they stock cutters made to cut Aluminium (and its alloys), and both HSS and carbide.

Thor

[JasonBModerator @jasonb]

For general use you could start with just a couple of sizes say 5 or 6mm and 10mm, flat centre cutting ends and 3-flute are good all round cutters. Add any specific shapes and sizes as and when you need them.

If your budget allows then get coated ones for the steel & iron and separate ones for aluminium which can also be used on the brass and bronze, these tend to be uncoated and have a steeper helix angle to help remove the amount of swarf produced

Yes Weldon shank will be fine in your collets just make sure all the flat is within the gripping area of the collet

I won't suggest any suppliers as the ones I use will unlikely be economical to buy from, better local or mainland Europe.

[Martin King 2Participant @martinking2]

Jason, You have a PM

Martin

[Maarten KipParticipant @maartenkip72631]

Thanks Jason and Thor!

[Clive FosterParticipant @clivefoster55965]

I tend to buy YG Only One 3 flute cutters as Cutwel prices are reasonable and the extra over plain HSS is worth the performance and life gains. Especially when that bit of "saved until its useful" material turns out to be a bit more obdurate than expected. Cope well enough with aluminium alloys at manual machine speeds that I see no great benefit in getting more appropriate material specific cutters. Being three flute centre cutting they do both slot drill and end mill duties.

But I don't buy many cutters, mostly when I have to have metric, having a lifetime supply of old style HSS 2 and 4 flute cutters in imperial sizes.

If you are buying weldon flat cutters consider getting enough sidelock holders for the cutters you generally use to leave one of each size permanently mounted. Quicker change than collets, stick out is always the same and no possibility of inadvertently switching between cutters of the same size so ending up with the whole stock blunted simultaneously. I found out the hard way that its easy to loose track of which cutter is being used and which is the sharp one waiting to be switched in. Shoulda got properly organised earlier.

Consider getting a small insert type cutter to use should you have anything obdurate to handle. I got a Little Hogger three insert one from Chronos years ago, shortly after they first came out. Not an everyday cutter but when I need it I need it. Nice thing about that one is its ability to take triangular, square and round inserts.

If you aren't equipped to sharpen cutters do remember to exploit the flanks by cutting as deep as you can within the common rules :-

for end mills, which cut on the side never in a slot, depth equals diameter and step over 1/4 diameter

for slotting with two or three flute cutters depth equals half diameter.

However centre cutting three flutes like the YG ones I like are frequently happy at 1/3 rd diameter step over, maybe more, when on endmill duties.

There are only so many passes the cutter can make before the ends become blunt so you might as well get as much metal off as you can for each pass.

If you can re-sharpen cutters nibbling away at 1 or 2 mm a time might work out better as you can take 2 or 3 mm off the end several times when resharpening before the cutter gets silly short. I have some doubt that re-sharpening is worth it for folk like us. The machinery isn't cheap, learning to do a proper job takes serious time and cutters are quite reasoanbly priced these days. Unless you luck into something seriously underpriced the cost setting up to resharpen properly probably buys over 100 endmills.

For us the big win from re-sharpening is likely to be getting out of jail when you've just blunted the last cutter of the size you must have. Most likely when the cutter you are using is getting old and balks at a piece of "saved material". So you assumed its time to change the cutter when in fact the material is super obdurate and promptly kills the nice new cutter.

Yep. Been there dunnit, got the tee shirt and wrote the book.

If a cutter balks always test the material with a file just in case. Even when you "know" what it is. Yep, gotten that one wrong too.

My T&C grinder is pretty much dedicated to drill sharpening because its so nice to be 60 seconds away from a real sharp drill.

Clive

[Maarten KipParticipant @maartenkip72631]

Thanks Clive for your elaborate answer!

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