Author Topic: parting off tool  (Read 5474 times)

Offline polecat

  • Jr. Member
  • **
  • Posts: 55
parting off tool
« on: September 15, 2016, 05:34:23 AM »
ok lads can you recomend a parting off tool for my c3 lathe 10mm shank and what speeds would you part off steel fast or slow i'm a beginner at this as you may sumise
polecat

Offline PekkaNF

  • Hero Member
  • *****
  • Posts: 2523
  • Country: fi
Re: parting off tool
« Reply #1 on: September 15, 2016, 08:17:35 AM »
10 mm shank is really small. I have about 150kg lathe with 550W induction motor, 20 mm shank for GTN2 inserts (Iscar) and justabout get near 50 mm in any material and 30+ mm on tempering steel. Top slide removed for rigidy.

* What material / what diameter?
* Are you willing to use any coolant?
* Are you willing to grind HSS?

Pekka

Offline polecat

  • Jr. Member
  • **
  • Posts: 55
Re: parting off tool
« Reply #2 on: September 15, 2016, 09:30:00 AM »
i have a job i'm doing for my motorbike i need 2 shims of steel 19.6 mm od with id of 16mm i've done that bit ok but i need to part them off the tool i have now is not up to the job  hence asking about speeds and a new tool
i am a time served engraver so know about sharpening cutters /drills i thought a tungston parting tool would be better at doing steel or better still an insert tool please advise
thanks polecat

Offline John Rudd

  • Hero Member
  • *****
  • Posts: 2525
  • Country: gb
Re: parting off tool
« Reply #3 on: September 15, 2016, 12:02:05 PM »
You newd a machine that  is pretty rigid when it comes to parting off....

I also have a C3  ( Sieg) but even  with  a 2mm parting blade it struggles....yet my bigger lathe on a GTN3 insert is a breeze...(1.5kw motor with vfd... :) )

On a C3, I think I'd go for a GTN2 make sure everything is locked up tight and go for 200 rpm...add a bit of lube for good measure..
eccentric millionaire financed by 'er indoors
Location:  Backworth Newcastle

Skype: chippiejnr

Offline bp

  • Full Member
  • ***
  • Posts: 119
Re: parting off tool
« Reply #4 on: September 15, 2016, 10:27:27 PM »
I have a Sieg C3.  I use either a 1/32" wide blade or a 1/16" wide blade, both from AR Warner in the USA.  The lathe can part off 25mm diameter 12L14 (free cutting) steel very well at something in the order of 200 to 300 rpm, with lots of squirted on oil, I use Inox.  The difference is the spindle is run "backwards" (i.e. clockwise looking from the tailstock), and the cutter is mounted upside down.  As the C3 is a modern machine with a bolt on chuck there is no danger of the chuck unscrewing.

Here are a couple of pictures.....



Best of luck!!
cheers
Bill

Offline NeoTech

  • Hero Member
  • *****
  • Posts: 826
  • Country: se
    • Roughedge Hobbyworks
Re: parting off tool
« Reply #5 on: September 16, 2016, 09:29:13 AM »
I have a large machine and tend to avoid parting off if i can.. hacksaw and turnning the chopped end is the safer solution many times.
Machinery: Optimum D320x920, Optimum BF20L, Aciera F3. -- I have not failed. I've just found 10,000 ways that won't work. http://www.roughedge.se/blogg/

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8966
  • Country: gb
  • East Sussex, UK
Re: parting off tool
« Reply #6 on: September 16, 2016, 10:04:11 AM »
Rigidity, confidence, and preferably an inverted parting tool in a rear tool holder are your friends parting off.

Rigidity - reduces the tendency to dig in

Confidence - don't just tickle the part with the tool give a smooth regular in feed with no hesitations

Rear Tool - the geometry of a rear mounted tool makes it tend to move out of the cut if a dig in occurs
Andrew Mawson
East Sussex

Offline PekkaNF

  • Hero Member
  • *****
  • Posts: 2523
  • Country: fi
Re: parting off tool
« Reply #7 on: September 16, 2016, 12:59:09 PM »
Yeah. I second to rigidy. It was hopeless with original toolpost and topslide. When I ditched the top slide and put oversize toolpost with two sizes too big parting off tool and parting off has been much easier. Also plan work order such that you can part od near chuck and if long piece, take tail stock out before cutting trough.

Pekka.

Offline rogprov

  • Jr. Member
  • **
  • Posts: 7
  • Country: gb
Re: parting off tool
« Reply #8 on: September 16, 2016, 04:13:37 PM »
I've had good results from grinding one from a 12mm HSS blank.

Like this

The picture comes from http://www.mini-lathe.com but mine is almost the same.

Roger

Offline polecat

  • Jr. Member
  • **
  • Posts: 55
Re: parting off tool
« Reply #9 on: September 17, 2016, 06:24:09 AM »
thanks lads job done 2off 19.6 od 16mm id and 0.8mm thick watched a few youtube vids slowed the speed down and it went ok quite chuffed
polecate