Annoying the neighbors with TIN milling cutter

[BOB BLACKSHAW 1Participant @bobblackshaw1]

Hello

I have been making a simple joggling tool out of 7mm square mild steel, I used a 12mm Tin coated end mill. I needed a 2.38mm step on this so with the SX2P mill cut .4mm for 40mm long. The noise from the cutter was neighbour annoying for Easter Sunday but got one of the joggling tools done. I then got a cheap tool 12mm HSS from China done the same and it cut brilliantly and in half the time. What use are Tin cutters for, I'm not going to use them as all they do is create a noise and seem to rub on the material and not cut. Its a shame because I have quite a few but reluctant to use them.

[BOB BLACKSHAW 1Participant @bobblackshaw1]

[JasonBModerator @jasonb]

Sounds more like the Tin cutter is blunt or just poorly ground as a good one won't make anymore noise than a uncoated one of similar quality.

If you are cutting your 2.38mm steps in 0.4mm passes they that is just going to wear off the corner of your China cutter and it will end up no better than your Tin one. Even being gentle with the machine two passes of 1.2mm should be all that is needed.

[MWParticipant @mw27036]

I have bought uncoated HSS cutters from china (No, they were not a "set" ), whilst I expected the quality to be on the minus side they're actually pretty good, and certainly compare to some of the better ones I have. I was able to mill a small section of my table vise away with it in order to make it fit my table.

I do have some blunt M6 taps at the moment, they're almost as bad as just extruding a thread. So I think this might be a good time to make another tracy's purchase.

I did, used to use my machines indoors, but then noise becomes all the more apparent. I have since moved into my own space where i'm unlikely to annoy anybody, I suggest this would be a good idea!

Michael W

Edited By Michael-w on 16/04/2017 13:18:41

[BOB BLACKSHAW 1Participant @bobblackshaw1]

The Tin coated cutters all look a bit rough all the way up the spiral and have had minimal use, I got these from a uk outlet, not mentioning names. As for my .4mm passes I generally a bit cautious with milling and lathe but will give a larger cut from now on.

Thanks.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by BOB BLACKSHAW on 16/04/2017 12:40:45:.

What use are Tin cutters for, I'm not going to use them as all they do is create a noise and seem to rub on the material and not cut. Its a shame because I have quite a few but reluctant to use them.

The very nature of coating a tool will tend to blunt it at the microscopic level because you start with a sharp tool and then put an even coating all over it. However, this is probably a red herring – I think that having gold coloured tools is a cheap way of pretending that the product is of superior quality. In principle though, I think that coated cutters are a boon to the model engineering fraternity since they help us to get good results without using coolant and there are now many other coatings besides TiN.

It's the usual caveat I'm afraid: Expensive, branded tools have consistent quality. Cheap, unbranded tools may or my not be of good quality.

Cheers,

Rod

[MWParticipant @mw27036]

Posted by Roderick Jenkins on 16/04/2017 13:46:06:

I think that having gold coloured tools is a cheap way of pretending that the product is of superior quality. In principle though, I think that coated cutters are a boon to the model engineering fraternity since they help us to get good results without using coolant and there are now many other coatings besides TiN.

I agree it does seem to be a visual exercise rather than a proof of practicality. As you say, the very nature of coating it makes it hard to maintain a decent edge which may be why I've found the cheapest of the cheapo uncoated ones can still cut well. And if it doesn't then I've still got 5 more of the same size!

A lot of carbide tipped tooling also has been ground for a particular purpose on lathe tooling and does not necessarily mean it will work to a good finish on all materials,

I have found that the ones intended for aluminium give a consistently decent finish on plastic whereas the standard ones often intended for steel are blunter and not good for soft materials finish wise, which is why unless I know i'm going to turn hard steels i'd rather use home-ground HSS tools.

As these are both cutting tools for either mill or lathe work, I do wonder if the same argument applies to milling cutters when they are "general purpose".

Michael W

 

 

Edited By Michael-w on 16/04/2017 15:01:53

[JonParticipant @jon]

Totally agree there the goldy coating giving some means of a superior cutter. The steel used combined with the grinding is real poor quality as said many many times before and false economy.

Now the Seco goldish coating is rock hard over quality steel and with razor sharp grinding lasts 30-40 times longer than above. Its what I use to mill the tough 200/250 series tool holders and can do 7 whereas a quality brand name (not a shops brand name) carbide may not even do one, above cheapy not even one pass, that's the difference.

[Howard LewisParticipant @howardlewis46836]

Agree with everyone saying that TiN coating does not guarantee a better cutter. The coating is supposed to reduce friction and extend tool life, as I understand it.

A tool which is incorrectly / badly ground, or blunt, will not cut properly or quietly, whether coated or not.

Usually, if a tool chatters, the speed is too high, and reducing the speed should improve matters. Also, the feed should be related to the type of cutter, and the material from which it is made. As a rule of thumb, do not exceed 0.002 inch / tooth for an end mill. Difficult to judge with manual feed, but with practice, you will get the hang of it.

Of course, this assumes that the workpiece is rigidly clamped, and that the machine is well adjusted, and sturdy enough for the task.

Howard

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