Thread: Old lathe clean up Newbie

Hi Chester, Guys,

I agree 500 rpm is about right for a 16 mm drill in mild steel. Personally I prefer to go a little lower in speed with large drills, say around 350 rpm. The problem is unless you have the workpiece firmly secured there is a risk of the drill grabbing and you not being able to hold it. A 6 mm pilot hole is Ok with the drill at about 900 rpm.

Whilst step drills are Ok for sheet and thin stuff, I wouldn't use them for anything above a couple of mm thickness.

Prior to getting a lathe...

I wouldn't normally have considered a step drill, except I was being cavalier due to the 'cheap' price of the $5 set and needing to enlarge the bore through a motorcycle rear wheel bearing spacer from 15mm to 20mm - I thought this step drill won't work and will blunt before it makes any headway.

The spacer wasn't hardened bearing steel, but it wasn't soft stuff either.
The 20mm step drill did surprisingly well for the three steps 15mm-16mm, 16mm-18mm and 18mmm-20mm, through about 20mm depth of the spacer.

Clean hole and none the worse for wear.

FWIW - It isn't one of the step drills with the quick change 1/4" hex shank, it's got an 8mm shank with three flats for the chuck teeth

A bit of suitable cutting fluid or lubrication will probably help things along.

Well the foot plates drilled relatively easy, 4 mm pilot and the new Sutton 16mm drill bit with probably way to much cutting fluid went through with no problems.
foot plates.jpg

A QCTP from Mag Pro arrived, prices on their website and stock levels seem to differ from their ebay store, direct was cheaper. Seems plenty of good deals in their store with prices not that much more than Ali Express with far quicker delivery. Tool post took 5 days to arrive. Ordered a heap of tooling from Ali though as they seemed heavy duty at a very reasonable price, we will wait and see.
QCTP.jpg
tool 1.png
This is the spec and style in various configurations.

Hopefully this week the weather will improve and I can make some headway in the lathe and stand.

Are all the tool holders for TN** inserts?
The N is negative rake. Nothing wrong with that and you generally get double sided inserts meaning more cutting edges/points per insert and they are usually quite robust.
Not so good for lighter cuts though, and on my Takisawa lathe of similar size my go -to inserts are mostly CCMT.
I started off with mostly negative rake inserts like WNMG (and still use them for heavy cutting or interrupted cuts) but found the CCMT much nicer for general work.

Steve

Originally Posted by OxxAndBert

Are all the tool holders for TN** inserts?
The N is negative rake. Nothing wrong with that and you generally get double sided inserts meaning more cutting edges/points per insert and they are usually quite robust.
Not so good for lighter cuts though, and on my Takisawa lathe of similar size my go -to inserts are mostly CCMT.
I started off with mostly negative rake inserts like WNMG (and still use them for heavy cutting or interrupted cuts) but found the CCMT much nicer for general work.

Steve

Not necessarily, as I've ranted about before.... I've been roughing with a CCMT or KNUX lately, and finishing with 0.2mm off the diameter cuts (and sometimes less) with a negative rake CNMG at 750 rpm and getting a mirror finish. It's mostly in the chipbreaker.

Conversely, while these Tungaloy NS530 CNMG 120404-11 are capable of taking finer cuts (while retaining excellent finish) than any of the various CCMTs I have on hand (No CCGTs here), trying to take much more than 2mm off the diameter makes the lights go very dim as 5hp of motor bogs down, and produces chips that are just about glowing. Horribly inefficient, but they're not designed for that use - the -11 geometry is specifically intended for finishing. Hence, as I say, roughing with CCMT - it's faster with the quick change toolpost to slap in the CCMT tool or the KNUX tool than change the insert in the CNMG tool back and forth, and any crappy eBay regular old CCMT off the shelf is capable of taking much more material in a pass than these CNMGs.

I really need to stick one of these CNMGs under the microscope to help illustrate the point (literally), they look like a CCGT on steroids.

I've also got some TNMG inserts for my boring bars with a deep groove molded in, which makes them a highly positive cutting edge. Nose radius is a bit big for super fine finishes, but they cut incredibly freely (more so than the CCMT boring bars).

Point is, ANY holder, regardless of insert shape or rake, is only going to perform as well as the geometry molded into the top of the insert you install in it (and in some cases, the nose radius you choose). The only really relevance of the insert designation is how well supported it is in offering those choices. To paraphrase an old advert "Inserts ain't inserts." Buy two sets of generic Chinese 'CCMT' off eBay from two different sellers, they probably won't have the same chipbreaker geometry, and one may not work anywhere near as well as the other...

Some of the 'Negative' geometries are much easier to find affordable NOS genuine branded inserts for than the 'positive' geometries....

I've noticed the price differences and product and stock differences also for Mag Pro between their ebay story and their website - the website doesn't seem to get much attention.

I suspect that the price differences are ebay and paypal fees and shipping if it's included in the purchase price

I've been meaning to get a tool or two from them and was planning to ask them if buying direct from them for a product only listed on ebay, which isn't on their website, works out better for them.

Out of interest, what size toolpost did you get?

Yes initial tooling is all negative rake and these are the cutters I ordered to go with the relative holder. General metal and ally. Happy to take suggestions if I should be purchasing a certain holder and cutter to compliment what I have ordered already.

All DESKAR.

VNMG160408-TM LF9018, 10pcs

WNMG060408-TM LF9218, 10PCS

SNMG120408 HA GH02, 10pcs

TNMG160408-TM LF9018, 10PCS

TNMG160408-HA K10, 10PCS

SNMG120408-TM LF9018, 10PCS

VNMG160408-HA K10, 10pcs

Thanks
Chester

Originally Posted by ruckusman

I

Out of interest, what size toolpost did you get?

The tool post is the 250-222 model, listed as the 10 inch to 15 inch swing on the M&G website. Was only $235 which was cheaper than aliexpress, stock wise it showed no stock on the ebay store but 8 on their direct website. Generic kit comes with the 4 different tool holders and a knurling tool. Quality wise they seem to be built quite well, just need to order some extra 201 / 202 / 204 holders. The pricing on extra holders is all over the place ranging from about $15 to $35 each, so some digging between aliexpress and ebay to be done to find the best deal as I want another 10 holders to get me started. I'm thinking you wind up with a cupboard full of these to use the tool post as intended.

regards
Chester

These are the current holders on the way
EDGEV MSDNN.png EDGEV MTGNR 91 Degree.png EDGEV MTFNR.png
Then right and left hand of these couple
EDGEV MWLNR.png EDGEV MVJNR.png
boring bar in 8mm, 10mm, 12mm and external threading
SDUCR 8-10-12.png EDGEV SER.png
With the few clamping style tools from the old set that came with the lathe I think I should have enough to get my hands dirty in the learning process. Other than an internal threading tool of some sort is there anything I should have on my list of must haves for learning? A few people have mentioned the EE diamond tool holders for making the use of HSS easy, what about the Maxigear holders? seem like a similar idea.
Again, I appreciate all the input and ideas put forward.

Regards
Chester

Originally Posted by getshafted400

I'm thinking you wind up with a cupboard full of these to use the tool post as intended.

regards
Chester

I have 16 holders, and I still find myself changing tools over in the holders every now and then. The more varied the work you do, the more different tools you like having set up and ready - for example I've got 3 different size boring bars set up at the moment, a 30, 20, and a 10mm (which I just changed from a 12mm yesterday so I could get inside a smaller bore).

With regards your inserts - interesting choices as to shape, perhaps not ones I'd have made myself, but they'll certainly work. Deskar actually provide a decent range of inserts, in that you actually get to choose a chipbreaker (the two letter code at the end), but no real documentation on them that I can find, so you have to guess what the different chipbreakers are intended for!

The following is entirely my opinion, and I'm reliably informed I'm usually wrong.

It looks like the TM geometry is a pretty normal general purpose geometry, should remove metal quite well, and give good finishes on decent depths of cut. Probably won't finish nicely on light cuts, especially with the 08 nose radius - it will need to be doing some work to give that nice finish.

Looking at the shape of the HA in the middle two photos here: https://www.aliexpress.com/item/1005005837111207.html

They have quite a deep scallop on top that spans the full length of the side, rather like a CNMP insert, and appear to have very little 'land' molded into the cutting edge. These should be somewhat more freely cutting than the TM, and may finish better, although the 08 nose radius may counteract that, an 04 in that geometry would likely finish quite well. Chip control may not be as good as the TM in many materials, more likely to produce death ribbons, but

Where it gets interesting, is when you look at their CF geometry: https://www.aliexpress.com/item/1005006727892087.html

These look kind of similar to my beloved Tungaloy CNMG120404-11... A prominent cutting tip, with a deep short scallop behind it coming right out the sides of the insert, creating the image of quite an aggressive hooked tip, and a prominent chip breaking ridge in the middle. These in an 04 nose radius I reckon would be well worth an experiment if you were looking for a finishing insert.

OxxandBert, want to try out the WNMG080404-CF? I'm actually kind of tempted to try them out if the price stays at $25 when I log in, I've got a WNMG tool I never use because the inserts I have are crap, and I have plenty of other choices....

Originally Posted by Jekyll and Hyde

…..
OxxandBert, want to try out the WNMG080404-CF? I'm actually kind of tempted to try them out if the price stays at $25 when I log in, I've got a WNMG tool I never use because the inserts I have are crap, and I have plenty of other choices....

Sure thing. Just ordered some in the stainless carbide flavour.

Steve

[QUOTE=Jekyll and Hyde;2014977] interesting choices as to shape, perhaps not ones I'd have made myself, but they'll certainly work.

Thanks for the input. Being a newbie I looked at a tooling chart showing how the cutting edge interfaced with the material and went with holders that looked like they gave a range of cutting options. Was surprised at how many choices there was and so many seem to do quite a similar range of cuts but with different shaped cutters. I'm sure there is a reason for the subtle differences but at least I have a starting point. From what I have read on this forum and others the rabbit hole is pretty deep in this hobby, so sure with some time the tooling collection grows and as you suggested you get your favourites for the way you work.

The actual carbide cutters wow, took me a day of reading to get my head around the indexing codes to even have a small understanding of what the code was telling me. The sandvik.coromant.com site and secotools.com site are full of great resources and learning that I am sure I will come back too many times to grow my understanding. Cross referenced all the cutters and chose some pretty basic all round profiles with a medium radius as a starting point to get a feel for the lathe . Hopefully by keeping variables to a minimum across the different shape cutters/inserts I won't be introducing extra problems to understand, that's my thinking anyway. Really appreciate when someone takes the time to put up a response that guides and grows my very basic understanding. Will order a few 04 radius of the same inserts so I can compare on finishing.

Thanks again for your input.
Chester

Don’t get too hung up on the holders and inserts - you’ve got more than a good enough variety there to get you started.
You definitely don’t need a QCTP holder for every tool (but if that’s what you want there’s nothing wrong with it either)

A couple of the really interesting and satisfying aspects of the hobby from my perspective are working out ways of machining something with the tools you have - (which likely won’t be the perfect ones for the task), and the making of tools and fixtures etc to fill in the gaps in your tooling inventory.
Those things keep you thinking and also give you a good sense of satisfaction when you build a tool etc from scratch that works.

You will screw things up, break tools, get frustrated as heck at times but the main thing is just get into it with what you’ve got and make stuff and have fun!!

Steve

Hi Chester, Guys,

I know that I keep banging on about HSS ! But at least you quickly learn what works for you. You do learn about cutting edges and the shape required.

With carbide inserts you have to learn which one works best for your machine and for each job and material. It very quickly gets expensive, where as regrinding a HSS tool bit takes just a few seconds, and you get an almost as quick a result.

I got rid of my QCTP a long time ago and made my own Norman patent one !

25-09-2018-006.JPG
Norman Patent tool holder.