Indexable Carbide Tips and Tricks

Now I've got a new 9 piece set of indexable tip tooling , I realize that I will have to have some replacement tips to hand before long as the current one wear out .
When you get the replacement tips & brand new tools already tipped up is there any need to give them a wipe on an Arkansas stone etc.to sort out the cutting edges or is it usually fit and start working without doing anything to them ? .
 
For indexable tooling/inserts, you don't need to do anything to them, they are ready to use right out the box. You can try touching up the cutting edge on an insert as they become dull if you want but the whole purpose of indexable tooling is so that you are able to change out an insert (when dull or broken) and continue machining without having to worry about tool position (datum).

I never bother with touching up indexable inserts or regrinding them. As a hobbyist it will save you money but I rarely pay full price on inserts anyway so I just swap them out. I never throw any away though for some reason, well only the ones that are badly damaged.
 
Before anyone embarks on a long winded discussion on the relative merits of sintered carbide over high speed steel tooling let us have a look at history first.
HSS (high speed steel) replaced carbon steel tooling for production work over 100 years ago.
Sintered carbide tooling (first developed in Germany) replaced HSS in the 1920's for production work, carbide tooling technology has progressed considerably over the last 60 years, geometry, coatings and the manufacturing process itself.

Therefore do not expect modern carbide insert tooling to be very friendly when used on machines not particularly suited to it.

If you feel the need to use it choose tooling that resembles HSS tools regarding geometry and edge preparation, positive rake triangle tools are my go to choice when the setup is not ideal, such as deep bores and turning longish parts where chatter is likely (will surely happen).

Just my experience over 25 years working in a machine shop of course, your mileage may vary (-:
 
Thanks Wreck Wreck,
I did indeed notice that the old pensioner lathe I have chattered & fair tore into the steel a lot more than when I was using my MK 1 precision eyeball ground HSS tooling .
That's when I wondered about the idea of having to zip the new index tips across an Arkansas stone & ended up asking for that reason .

I upped the cutting speed to nearly40% faster and that went to some way to reducing the problem, taking to a it higher speed was hopeless except for a top speed fine cut to finish .

Would you give me your thoughts on the ring type indexable tips for stripping metal off along a bar ? I have a couple of HSS home ground cutters that I've made with a radius tips that work well , I've also ground up a couple of pointed tips with a very slight radius on the tip that work well on stripping the meat off bars too. .
 
There's basically 2 types of inserts, negative & positive. The round inserts I have are positive (RCMT) but they are ground high positive polished inserts for use with aluminum (RCGT). I find that they give a nice finish at higher feed rates than say a 1/32" nose radius insert. What's great about round inserts is when you need a new edge, you can turn it ever so slightly to get a fresh edge so you can imagine how many "cutting edges" you will get, well if you're using it for turning or facing.

But I mainly I use them for making grooves & radii close to a shoulder. These are Ti 6-4.

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Thanks Will ,
I just lurv those shiny coloured well finished parts& the bright ones as well ..They look good enough to be conversation pieces ,so what are they for ?:)
Do you make your own tungsten or titamium darts by any chance ?

This index tip thing is a whole new language for me to get hold of . I think I'll have to swan around the internet looking for some translation charts so I can work out what I might need long term .
 
Sorry David, I totally forgot to reply to your post. The ones on top are 10" long ice picks, the one on bottom are 2 spears that screw together to make one spear 30" long. You know, a friend actually asked if I could make Ti darts. We don't see him anymore so I never went forward with the idea. Tungsten I have never messed with. I do have some zirconium that's been sitting here. It so much more expensive than Ti that I'm waiting for a worthwhile idea to use it for.

Yeah indexable tooling can be very confusing, took me a bit to figure it all out. I'm no expert on indexable tooling & I don't work in production nor am I machinist by trade, but I can offer some suggestions on where to start if you'd like. What size is your lathe & what is the max tool shank size does it accept?
 
Thanks Will

It's 1943 or so old British made Sphere back lathe similar to the Atlas 10 F of the day , it has a ten & a half inch throw , with a 5 " chuck , I have the original 3 & 4 jaw chucks & the original face plate plus the original lantern tool post c/w cup ring and wedge . It also had a MYFORD over center fulcrum tool clamp that could handle 1" square tooling and a more modern MYFORD machined block four face tool holder that took up to 1/2" square shanks

It wasn't as good as I think it can be with these arrangements so I have lashed out and purchased a QCTP . This qctp can handle all the various high carbon , HSS square & square tool steel that came with the lathe when I purchased it .
To give a bit of standardization I purchased a boxed set of nine pf 16 mm shanked indexed tools , The QCTP has 2 x round bar , one 5/8 x 3/321 parting , one knurler complete & four more 16 mm square straight shank holders .

One thing I have done was take up as much play in the slides by adjusting the gibs & had to file the top of the compound slide down flat as some Pratt had used a standard high tensile bolt to fit an ancient Myford fulcrum arm type tool post , it has obviously been rotating in the slot as the slot has a definite cone " chavelled out" mid way along consequently starting to pull the top lips of the "T" slot upwards by about 15 thou.

I gave it a bit of a test run for a week or so and have found it totally different to the older cutting tools and older tool posts.

So any tips to think about would be most gratefully read and worked with .

The QCTP is a piston type with two faces at 90 degrees to each other supposed to be a best fit for a 10 to 12 throw lathe. the tool holders accept 5/8 " ( 16 mm ) square tools ( the next size down would have only been able to take 1/2 square tooling .
I didn't fancy the smaller size tooling for an 8 to 10 inch throw or the available QCP for that range of lathe . for after consulting the oracles on the site I gather that is would not have been so solid when sat high up on the compound slide . i also had a lot of 5/* tooling for HSS , brazed tungsten tips and some ancient hand forged high carbon steel tooling.

Re .. Darts :-
I did meet a guy about 20 years ago who swore that he had machined & ground up some used depleted uranium rounds recovered from a gunnery range where he & the " warthogs were playing ".

I don't know if he was talking through his butt , however the barrels of the darts were exceedingly heavy , like thin knitting needles & flew to the board like guided missiles .
 
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