Tool post height

wow that looks like the dogs............ ca $10 on Ali

looks like you would use that with a standard myford clamp

https://www.myford.co.uk/acatalog/TOOL-CLAMP--74-1409-1-1278.html

I'll go and check tool height and revert

The smallest tool holder for some inserts is 16mm so no choice. The TNMG is a case in point. I’ve just got some polished inserts for aluminium at a very good price and they work really well. The tool holders are cheap on the auction site.

MLA version QCTP with no overhang

Alan

Alan, unless I'm missing something the holder still has no direct line of support under the tool and is over hanging from the toolpost which is the "disadvantage" people are talking about

my lathe never been that clean, eat you dinner off it

For those who would like TNMG inserts, but don't have a big enough lathe to take the common size 16, (there are smaller, but they are like hens teeth), you can look at WNMG 06 which has all the advantages but is smaller.

The reason i posted about using the larger tooling was not because there is anything wrong with the smaller items.

The are so many cutters in the larger sizes of good quality over the smaller items, E.G. I have a 16mm boring bar ,which is a TIZIT, used . I paid £8.00 for it.

Steve.

Edited By Alan Jackson on 09/07/2021 17:37:32

I found at the model engineering shows all the bigger stuff was cheaper. I suppose because many model engineers have modest size machines. I’ve paid as little as six or seven pounds for a tool holder. Having machined a Sandvik tool holder for a friend I was confident of being able to machine them when needed.

that looks very solid to me, and simple. These triangle tips have a lot going for them

BTW has anyone come across a prog for decoding carbide language for tools and tips, ie you just put in the code and it spits out the spec

I saw it mentioned somewhere now lost in the mists of dementia

There's a useful pdf you can download here - (it's the one that used to be visible at Carbide Depot..)

Midwest Supply - Carbide Insert Designation

Re Carbide tip codes.

There was a thread on here, not too long ago.

Look through previous threads, or use the search facility.

Howard

heres my take on the tool height dilemma

hope it make sense - for illustration only as you must check your own dimensions

so with the desirable and plentiful 12mm holder you can

a) skim 2mm off the holder base (or part skim as suggested leaving a step on the overhang)

b) Skim the top of the topslide - but then the 4 way block will be wrong and you will need shims for a 5/16" hss

c) Make up a 4mm shim piece to fit under the holder and use the elephants foot

d) buy a new chinese machine and stop dickering around

What do you think

Obtw I have made the assumption that a 12mm holder will also mean the height of the tool tip - is this always right?

Another member mentioned the use a  16mm holder and doing some skimming to make it fit.  According to my estimate it should fit as is under an elephant foot see below - pls advise as I dont have one of these yet and I was thinking of getting a set with  triangle pieces (in fact it was steviegtr as above)

Edited By brian jones 11 on 10/07/2021 16:02:34

Edited By brian jones 11 on 10/07/2021 16:06:07

Personally am averse to making any irreversible changes to the machine, so would advocate milling the underside of oversize tool shanks.. (But not enough to weaken them seriously. 2 mm off a 12 mm will not be as weakening as 2 mm off a 8 mm shank.

Stiffness is BD^3 / 12 , so keep D as large as possible in the interests of rigidity.

One or two tool shanks have been reduced in depth, but leaving the area immediately near the carbide tip at full section, for that reason..

Howard

Indeed I have been scrabbling around, but most of the links are to iso type tables (15 or so)

what I wanted was to input the code and the app would spit out the decoded result.

this could all be done on Xcel but I have so many dozens of unfinished little jobs I was hoping someone may have got there first

OBTW one member wisely noted that referencing US mfg beware as they use imp units vs metric for rest of the world and the coding maybe different

6mm and 8mm are also readily available you could just buy those and not modify anything, a bit cheaper too. Look through this album of mine virtually all done with 6 & 8mm shank insert tooling.

You may be surprized at what can be taken off with just a 6mm tool that happens to be in a QCTP with the overhang "problem" mentioned by others and all this on a far eastern machine. 1/4 depth of cut so 1/2" off diameter in one pass.

Edited By JasonB on 10/07/2021 16:15:58

Says it all really

Ok for clarity then what tools are you using in the vids, they dont look like inserts, brazed tip? HSS

it is said that you can get a finer sharp edge on HSS so make cutting easier. too sharpe an edge on carbide makes them liable to chip the edge too easily especially on manual feed.

It also appears that the combination of surface speed, depth of cut and feed rate are what can make all the difference

saw a vid on this on here somewhere - fascinating 3" billet taking off 10,20,30 thou same speed same power feed only mid one gave a mirror finish

30 thou he upped the feed rate, and it came out fine? how do you work all this out

have not got a grip on this yet

perhaps cnc s/w does all this calc for you/

The OP was clearly about insert tooling as per the picture so I don’t know why it’s changed to HSS?

.

Does it matter ?

… The thread is about Tool post height

MichaelG.