|Dave Cee||09/01/2017 20:44:49|
|37 forum posts|
Would I be able to use either size in my tool post? The 16mm tool holder is the same length as the TP (90mm) so would be held by all 3 screws. The 12mm tool holder would only be held by 2 or is that ok?
Also, the 16mm has 8mm tool bits rather than 6, or does that really matter?
Thanks for looking.
Edited By Dave Cee on 09/01/2017 20:45:16
|Paul Lousick||09/01/2017 21:25:53|
|805 forum posts|
I think you have to go for the 12mm tool holder because you only have a height of 15mm from the bottom of the toolpost to the centre. The 16mm tool holder requires a minimum of 16mm.
I use a 12mm holder on my 9" Southbend lathe which is a similar setup to your lathe. The cutter just sticks out a bit more than shown in the drawing below. Still very rigid and works well.
|colin vercoe||09/01/2017 21:27:15|
|19 forum posts|
The size of the tool shank is also the the height of the cutting tip so unless your toolpost can be adjusted below the 15mm indicated on image the 16mm tool will be too high, the size of the insert for home use will probably not matter larger insert is more robust and more expensive, securing the tool with two screws will be fine.
|Dave Cee||09/01/2017 21:32:27|
|37 forum posts|
Thanks Paul and Colin.
Have to say this is a very active forum, and very helpful!
I thought it might have to be the 12mm, also, just had an email from Tania @ EE and she only has 1 set of the 12mm in stock so I think I will grab those.
Thanks ever so much.
|187 forum posts|
At the risk of swimming against the tide I can't see why you wouldn't go for the 16mm and just drop the toolbit down a tad (1mm or so) in the holder so that it is still bang on centre. Wouldn't work for most carbide insert tooling, but for this particular design I can't see that it would be a problem. Always good to go for the most rigid set-up possible, and 16mm square is a fair bit more chunky than 12mm. That you can hold it with all 3 screws is even better.
(Disclaimer - I don't actually own one, so if someone knows better and can say that slipping the toolbit down by 1mm will compromise the function at all, I'll happily be corrected...)
Edited By Bikepete on 09/01/2017 21:37:38
|Paul Lousick||10/01/2017 02:20:05|
|805 forum posts|
Bikepete beat me to it. Mill a bit off the bottom of the tool holder
Edited By Paul Lousick on 10/01/2017 02:27:32
|Simon Collier||10/01/2017 03:49:59|
207 forum posts
i just measured mine. Two are 1/2 inch and one is 15 mm. I also have the left hand one. They all take 1/4 bits. In theory a 16 mm/8 mm might be more rigid if you like to take 3 mm cuts, but in practise, negligible. If you have the bit low down, it can bring the front of the tool bit jaws too close to the work for comfort on some jobs, such as facing. I would strongly recommend the 12 mm.
Edited By Simon Collier 1 on 10/01/2017 03:52:51
12663 forum posts
One thing you may have to watch if lowering teh toolbit is that you will get less clearance between work and holder as the bit is retracted, could get a bit tight on facing cuts
8mm bit will take more grinding than the 6mm.
|Dave Cee||10/01/2017 08:45:59|
|37 forum posts|
Thanks for all the replies .
Am going with the 12mm Couldn't go with the milling idea either as I have not got a Mill yet.
|Kenneth Deighton||10/01/2017 09:16:20|
|53 forum posts|
Hi Dave, you don't need a milling machine, just mount the holder flat in a 4 way chuck and skim off the amount you need, simple, done it before. Ken.
|John Haine||10/01/2017 10:09:54|
|1917 forum posts|
How would you mount it flat in a 4 jaw with that projection on the bottom? And quickly checking with a file the steel of the holder is hardened, so you won't get far trying to mill or turn it anyway!
|1576 forum posts|
I managed to mill a hardened Sandvik toolholder with a carbide mill so it can be done. I had to take 2-3mm off the bottom.
3166 forum posts
It could be done on a 4 jaw and use a carbide tool on the lathe, coming in like a tailstock
Easier I find if you first drill a small centre hole to depth, then skim off to the centre hole depth, a carbide tipped masonry drill can do the hole
edit: You will also get more grip/support from the upper/lower jaw on the chuck if you place a long piece of metal between the jaw and the workpiece, even a bit of clean HSS above and below would help spread the gripping force right across the workpiece
Edited By Ady1 on 10/01/2017 10:59:53
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