“Quality” milling cutters, adn where to buy?

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Good morning all,

I’ve had my mill a few months now and am starting to get to grips with it, made a few small parts and planning on buying and building a couple of Hemingway kits.

When I got the mill I bought a small selection of 2 and 4 flute cutters in a couple of diameters from ArcEuro. These have served me well and allowed me to learn, however some YouTube education has led me to believe that I will get better results with better cutters.

So I really wanted to get peoples opinions of the validity of this, and if it is correct what sort of budget should I be allowing for cutters, which are the better makes, and where is good to buy from?

Many thanks,

B

 

 

[JasonBModerator @jasonb]

Which ARC ones did you use? Their Premium range are a lot better than the “golden” budget range.

APT are also reasonable without breaking the bank. Cutwel do YG-1 which are a bit better again but price goes up and on a hobby machine you may not get the full advantage of what you are paying extra for.

If you are paying a bit more then think about type and use. Coated for steel and iron but uncoated and with suitable geometry for aluminium and non ferrous metals. Keep the two separate so the ali ones keep their edge.

I find 3-flute does for most jobs if you want to keep the number of different cutters down.Carbide are worth thinking about but do need a bit more care in use as they can chip if mishandled

Also think about how you use them, a hobby mill is often better run fast with lighter cuts than a big heavy industrial machine which can chug along and take heavier cuts. Have a read of the second half of this article of mine.

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Thanks Jason,

The 2 flute cutters were the “Premium” HSS type, the 4 flute ones were the gold coloured ones.

To be fair both types have cut everything I asked them to, I think the vids I have seen suggest better surface finish is achievable with more expensive cutters, nit sure how true that is.

I have been running fast and light (the mill obviously, I am neither fast or light) and keeping the two flutes purely for ali and brass.

 

Maybe a couple of more expensive 3 fluters might be worth an investment for evaluation.

[JasonBModerator @jasonb]

In HSS for steel/iron try

https://www.shop-apt.co.uk/3-flute-slot-drills-hss-8-cobalt-tialn-coated-40hrc.html

Non ferrous

https://www.shop-apt.co.uk/2-flute-slot-drills-hss-8-cobalt-aluminium-series-un-coated.html

 

Or Carbide for steel/iron

https://www.shop-apt.co.uk/3-flute-end-mills-45-helix-altin-coated-carbide-45hrc.html

or

https://www.cutwel.co.uk/milling-tools/milling-cutters/general-purpose-milling-cutters/general-purpose-carbide-milling-cutters/nc-mills-coated-carbide-milling-cutters/nc-mill-square-end/3-flute-nc-mill-general-purpose-x-coated-carbide-slot-drill-up-to-50hrc-plain-shank-g9f43-series-yg-1-g9f43

Non Ferrous

https://www.shop-apt.co.uk/3-flute-polished-carbide-end-mills-for-aluminium-un-coated.html

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Cheers Jason. 🙂

[Bill PhinnParticipant @billphinn90025]

The Arc Premium HSS type have given me good finishes. The only end mills that out of the box have in some cases not produced good finishes were the SWT-branded HSS ones that are widely available on Ebay, and the only slot drills some of the very cheap plain or TiN-coated ones.

The reason why those that didn’t cut well from new didn’t cut well became apparent to me when I looked at the leading edges of the cutting tips on the ends and noted they hadn’t been ground at all well, or were essentially already blunt.

On this point, sometimes milling cutters aren’t adequately protected in transit and will arrive with a chipped tooth, in spite of them being in their own plastic case. Examine all your milling cutters carefully on receipt.

Likewise, examine the milling cutters you’ve been using for a few months and see whether they are in fact still sharp.

On non-ferrous metals, the best surface finishes I’ve been able to achieve have been with a fly cutter. Once you’ve learned to grind and hone your own HSS flycutting bits and seen the mirror -like finish that can be achieved, on non-ferrous metals at any rate, I think you will always have a place for flycutters alongside your milling cutters.

On a final note, beware of Ebay sellers advertising “new” milling cutters that are either unboxed or in already opened boxes. I’ve reason to suspect that in many cases these cutters have in fact been used, even if only lightly. What many of these sellers are clearly capitalising on is that the difference between a worn milling cutter and a new one can be quite subtle and not immediately obvious to the naked eye.

 

 

 

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Thanks for the reply Bill.

As a general rule I don’t buy anything from Ebay, too many bad experiences in the past.

Funnily enough I have just finished making a fly cutter, currently using RCMT inserts, but will try with HSS.

Cheers,

B

 

[JasonBModerator @jasonb]

If you are using it on non ferrous then treat yourself to an RCGT insert which will work better, APT do them in twos so not a big outlay to try them out.

Having said that my flycutters seldom see the light of day now as I find the face/shell mills five as good a finish in a fraction of the time.

[not done it yetParticipant @notdoneityet]

Good advice above… but possibly only if your machine is capable of getting the best out of the cutters.  As JB states “you may not get the full advantage of what you are paying extra for”.

One member, who recently departed the forum, bought in professional grades of end mills from sellers to the commercial sector.  It is the same/similar with cutter holders – those really expensive ones (with very minimal run-out), that cost an arm and a leg are likely to afford no extra benefit if the machine is not up to a similar quality.

Do ignore the youtube reviewers.  Most will not give a poor review, so they will receive more items (often free) to review.  I know of one person who gave an honest review of some cheap angle plates.  There were no more offers of doing further reviews as the items were really of poor quality and everyone who watched the review would have realised that they were not really great value for money.

[Peter Cook 6Participant @petercook6]

One thing to add into the equation is the operator – at least in my case!

I am amazed how much better the surface finish is when I mill something using the rotary table – which has a stepper motor – in effect giving a very smooth power feed. Using the same cutters at the same speeds on the same material and manually twirling the dials at the same sort of feed rate gives me a much inferior finish – I presume because I can’t keep the individual tooth cuts anything like as consistent.

[Robert Bowen-Cattry]

On 23 September 2024 at 11:26 Robert Bowen-Cattry Said:

…

I’ve had my mill a few months now …

What sort of mill is it.  Fitting fancy cutters to a basic mill probably won’t improve it much.

When I got the mill I bought a small selection of 2 and 4 flute cutters in a couple of diameters from ArcEuro. These have served me well and allowed me to learn, however some YouTube education has led me to believe that I will get better results with better cutters.

Youtube has no quality control.  It’s a mix of good and bad advice.  Trouble is the best videos require an experienced machinist, who is also a good communicator, and knows how to make a watchable video.  Not that common.   Quite a few are made by inexperienced machinists with video skills, and it can be fun watching them to see how many inadvertent mistakes they make.  Another group are ‘influencers’ – rewarded in some way to push products, and therefore prone to bias.

My experience of ArcEuro is good.  I’d describe them as a careful vendor of mid-range products, priced to suit hobbyists, but capable of reasonable performance on hobby machines.   You need to ask exactly what a top-end cutter will do for you.   Briefly:

• Will be to specification out of the box – no blunt, mis-ground, or poorly hardened.   This is important to professionals because time is money, much less so to hobbyists who don’t mind a delay replacing a dud.
• Long life when run at commercial speeds.   Again, important to professionals, but very few hobbyists run cutters at anything like commercial rates.  Our machines lack power, speed and rigidity, and we probably don’t cool or remove swarf to spec either But in general, posh cutters last a bit longer than cheaper ones.   I’ve not found it worth paying the extra, but it depends on what you do in your workshop.
• Guaranteed balance for high-speed running.  Probably a waste of money in a hobby workshop.
• Making it less likely that poor results could be due to a defective tool.  That allows the operator to concentrate on what he’s doing wrong!  But a bad operator can quickly convert an expensive cutter into a dud: I’d rather learn on mid-range cutters and check them for damage with a loupe, rather than fling money at well-made cutters in hope they’ll survive my blunders.
• Bragging rights down the club!
• Also acceptable if coughing up makes you happy.   Many enjoy using good tools, even if they make no practical difference.   Reassuringly expensive is a thing.

So I really wanted to get peoples opinions of the validity of this, and if it is correct what sort of budget should I be allowing for cutters, which are the better makes, and where is good to buy from?

Simple answer, assuming lots of cash, is someone like Cutwel.   I doubt they get a lot of business from hobbyists though, because as a group we lust after industrial quality only until told the cost!   A nice 20mm 4 Flute Multiple Helix K2 Coated Carbide Chamfer Prep Weldon Shank End Mill from Cutwel is £124.10 plus VAT, and maybe postage.   Are you up for spending on that scale Robert?

My experience, based on relatively light experimental work in a Far Eastern equipped workshop is that posh cutters don’t make enough difference for me to spend big money on them.   Someone who works faster on high volume output needing a quick good finish might get a different answer, one that might include upgrading their machines as well.

Budget depends entirely on how much metal you cut.  Many small cutters are consumables, and it might well be cheaper to burn through several inexpensive cutters rather than tie money up in posh one.

Where not to buy from may be helpful.  This is difficult: ebay and similar do offer genuine bargains.  Trouble is they are mixed in with carp and it’s hard to know what’s what.   Avoid too cheap, vendors who don’t have an engineering track record, and imports.   Not that they are all dishonest, but a proportion are flogging manufacturing seconds, worn tools in new boxes, forgeries, and factory rejects.   The reputable UK suppliers are unlikely to send complete rubbish, and should refund/replace if a lemon gets to a customer.

…

B

 

 

Dave

[Neil LickfoldParticipant @neillickfold44316]

Depending on the mill size, but the rigidity of the machine will determine the depth and size cutters that can be used. Out here, under 6mm diameter cutters are fairly well priced. The cobalt HSS is a lot better at keeping a sharp edge over non cobalt hss. Carbide has it’s own huge field. I buy the non coated for ali, and the coated for steel. My most common cutter is the 3 flute and is a compromise on the 2 and 4 flute. I use the slightly worn cutters for roughing out and good ones for finishing. Cutters with a corner radius will last a lot longer than sharp cornered cutters. Some parts require a sharp corner, so do that with the finishing cutter.

Carful diamond filing or with the a diamond mounted point, you can sharpen HSS or Carbide cutters enough for roughing out at least. It takes time, but saves spending if finances are tight. A cutter can be sharpened many ways suitable for roughing and with great care for finishing as well.

Sometimes making it into a single flute cutter can be very effective for finishing, although can take longer for the process.

There are also multi flute cutters which work very well for fine finishing only, and allow for a higher feedrate of the cutter runs true. If the tool holder is not very good, and has an obvious run out, mark where the high side is, and use the cutter noting where it was last used. On heavy cuts all will cut, but on light cuts only the offset side will be cutting. The cutter can be rotated to the less worn edge etc.

 

[duncan webster 1Participant @duncanwebster1]

Tubal Cain (the British one, not that Yankee upstart) was an advocate of grinding a small chamfer on the tips of end mills. What we need is an equivalent of 4 facet drills for end mills. I’ve done it by hand, but not very accurately. Lovely surface finish, but not cutting equally on each tooth (let’s be honest probably only cutting on one tooth). The geometry is beyond me, someone out there will be able to do it.

[HopperParticipant @hopper]

For the little bit of milling I do on the Myford with vertical slide, I just use the absolute cheapest cutters from Aliexpress  China. So cheap they are not worth sharpening and they give good results. Surplus Chinese industrial kit, not ” hobby grade” I assume. China is not a manufacturing super power by using duff milling cutters  .

If you are getting bad finish on your milling  , there is a plethora of other factors that could be causing it. Be wary of taking anything on YouTube as gospel. Some of it is good. Much of it is not. Good sharp cutters help for sure but are not the whole story.

[JasonBModerator @jasonb]

You can buy cutters with the small 45deg chamfer for the same sort of price as a flat ended one you no real need to add one yourself. Though it can be a way to get a second life out of a cutter where onlt the corners have become blunt due to shallow vertical cuts. Just look out for the icon on the suppliers site

Likewise the ones with radius corners, I use them quite a bit but not so much for the surface they leave but they are ideal for mimicking the fillets on cut from solid “castings”. Also can be better than a ball nos ecutter as the cutting edge is moving faster. Again marked on supplers with an R.

Also the majority of carbide inserts will also have a corner radius, typically 0.8mm in the types we tend to use.

Dave picks an expensive 20mm cutter as an argument for cost but on the OP’s wM16B machine you would be paying for a lot of carbide that you can’t make use of. It may have a bit more stiffness for a deep single pass profile cut but the machine is possibly not going to hav ethe cuts to take advantage of it unless the cut is very shallow. Could use it for flat surfaces as it would need fewer passes but then you have paid for the rest that won’t get used. Better to do flat surfaces with a slow flycutter or an insert cutter if you want to get it done before tea time. That way you are only replacing a small amount of HSS or Carbide when it blunts not the whole thing and initial cost of holder will be less too.

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Wow, a lot of information to digest, thank you all so much.

I think my take from this is to stick with my current cutters until I break them, then maybe look at the APT or Cutwel offerings. I fully agree at this stage it is more likely my inexperience causing the sub-par surface finish.

Although I have got the hang of calculating the correct spindle RPM I’m still having trouble translating the movement speed of the table via the hand wheels. I expect this is an experience thing and I will get better at it.

[JasonBModerator @jasonb]

Don’t run them until they break, they will probably get blunt before that, if they are not already. Quite possible early learning has shortened their life so it could be the edge has gone off them, look at the last two photos in the article of mine if you are getting large burrs and/or fine swarf then it is time to change them

[Robert Bowen-CattryParticipant @robertbowen-cattry70600]

Thanks Jason.

[HollowpointParticipant @hollowpoint]

My advice as usual is slightly against the grain. Don’t be afraid to use eBay to look for new old stock. There is a vast selection of the very best cutters money can buy (usually at a fraction of the price of what they cost new) available. If you stick to sealed boxes or if the cutter is etched with the brand name you should be fine.

Look for these, all top notch:

Dormer, Presto, Sandvik, Seco, Kennametal, OSG, Europa, Osborn, Guhring, Widia, Kyocera, Ceratizit, Hertel, WNT, Meykstag, Walter, Iscar.

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