Parting made easy

[goldstar31]

Unfortunately, your reference on HSM refused to offer anything but 'question marks in boxes'

I'm using a fairly up to date Mac- if that means anything!

Diverting back to 'Thomas', his stuff is on Hemingwaykits.

Sadly, the parting off answers could be solved if those wanting information could find where they hid their pocket books and wallets.

 

[Richard Carlstedt]

So let me try this to help the thread and first show the concerns a machinist has to start a parting job
This is shown in the first two pictures.
The 3rd and 4 th Pictures illustrate what are positives for parting.
Please note the last photo shows why a rear tool post in mostly succesful because of it's location relative to the cross-slides centerline
Rich

 

[Paul C]

Excellent! Pictures are certainly worth many words

 

[goldstar31]

What lathe is being photographed please?

 

[propclock]

Thanks for that. I must admit I hadn't thought much about the
parting tool in relation to the cross slide, good on you.

 

[stackerjack]

So let me try this to help the thread and first show the concerns a machinist has to start a parting job
This is shown in the first two pictures.
The 3rd and 4 th Pictures illustrate what are positives for parting.
Please note the last photo shows why a rear tool post in mostly succesful because of it's location relative to the cross-slides centerline
Rich
View attachment 112180

View attachment 112181

View attachment 112182

View attachment 112183

I parted off a 3" diameter bar of tough steel a while ago. Imagine the tool overhang on that. But I still get jam-ups now and again. Plenty of practice, and a bit of luck are what you need.
Jack

 

[CFLBob]

I parted off a 3" diameter bar of tough steel a while ago. Imagine the tool overhang on that. But I still get jam-ups now and again. Plenty of practice, and a bit of luck are what you need.
Jack

The last one I had trouble with was 4" D2 tool steel blank on an 8-1/2 x 20 lathe. The cross slide couldn't be pulled far enough back to put a cutoff tool into the piece after I'd cut in about 1 to 1-1/2". I had to take the tool holder off the QCTP to clean the cut. I broke two cutoff tools. Went looking for a cutoff tool with carbide inserts and can't find one small enough for my tool holders. Most are 26mm, just over 1", my holders are 1/2" - can't handle even 5/8.

After my luck ran out, I parted it off with a carbide blade on a reciprocating saw. Which generated about a pound of sharp little splinters that I had for a week afterwards.

 

[Richard Carlstedt]

Goldstar
It's a Boxford Lathe ( Which is the British Version of the Southbend...but Greatly improved !)
I rebuilt mine (scraped the ways) and it is a bit different. The "Legs" of the carriage were ground parallel to the cross-slide ways, so when (but I never did) I put a Boring table on the carriage, it would have accurate support outboard for the table and be more stable. the ground surface is great for using a mag base indicator too. I am using a Southbend Taper Attachment (cross-slide), but the Tool-slide is Boxford. The ground Starritt Plate you see is for a DRO mounting and makes it really simple AND protected scale mount. you can see the scale just under the small black nob in the closeup picture. Since the top of a Taper attachment cross-slide is parallel already, you put in one pin (to the slide) and indicate the edge with travel and then pin and screw it down. The scale is then placed under the plate and is in perfect alignment and is out of the way (no damage!)
Rich

 

[Richard Carlstedt]

Double Post deleted

 

[goldstar31]

Thanks Rich

You had me baffled as I once had to sort out the damage which 'school children' occasioned before I could use it.

As you will have read, I'm a Myford sort of creature- and I had mine slideways ground and the worn saddle Turcited. The previous creature who used- misused it ran the gear box on mahogany dust- or so it seemed.

Thanks for your comments

Norman

 

[cobra]

The last one I had trouble with was 4" D2 tool steel blank on an 8-1/2 x 20 lathe. The cross slide couldn't be pulled far enough back to put a cutoff tool into the piece after I'd cut in about 1 to 1-1/2". I had to take the tool holder off the QCTP to clean the cut. I broke two cutoff tools. Went looking for a cutoff tool with carbide inserts and can't find one small enough for my tool holders. Most are 26mm, just over 1", my holders are 1/2" - can't handle even 5/8.

After my luck ran out, I parted it off with a carbide blade on a reciprocating saw. Which generated about a pound of sharp little splinters that I had for a week afterwards.

I certainly like the carbide tipped blades.
I built this holder for 26mm blade that fits my QCTP.
Makes parting a breeze.

Jim