Parting tool holder

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NP317
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Re: Parting tool holder

Post by NP317 » Fri Feb 14, 2020 10:29 pm

The actual insert holders are made from seriously hard steels. That will break before bending.
This is required due to the high forces involved during cutting.
RussN

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SteveM
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Re: Parting tool holder

Post by SteveM » Fri Feb 14, 2020 10:35 pm

whateg0 wrote:
Fri Feb 14, 2020 2:39 pm
Why not make one that fits your needs?
On my mill, it would take an entire day. Not enough horsepower and I still need to set up a multiple pulley system to make variable speeds / torque.

I'd rather be making stuff than making stuff to make stuff, especially when it can be bought. I just need to find it in my size.

Still working off an on on a 4-way toolpost for a friend.

Steve

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BadDog
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Re: Parting tool holder

Post by BadDog » Fri Feb 14, 2020 10:50 pm

I've got one of those adapters for the Sandvick blades. Inserts are a bit pricey, but last very well in my experience. And the blades are pretty pricey too. But these things have taken ALL the drama out of parting for me. With a rigid setup, they just simply work and cut beautifully every time.

And these type of parting tools MUST be held horizontal. You can't use the angled holders, even if you could find one tall enough.
Russ
Master Floor Sweeper

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SteveM
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Re: Parting tool holder

Post by SteveM » Fri Feb 14, 2020 11:14 pm

BadDog wrote:
Fri Feb 14, 2020 10:50 pm
And these type of parting tools MUST be held horizontal. You can't use the angled holders, even if you could find one tall enough.
The one I posted for the BXA toolholder is specially designed to take into account the angle of the toolholder. You would not be able to use a standard blade in the angled toolholder because the angles would add up to something that wouldn't work.

Steve

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BadDog
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Re: Parting tool holder

Post by BadDog » Sat Feb 15, 2020 12:04 am

Absolutely agreed. I was just making sure it was doubly clear for those with the insert blades like my Sandvick, those aren't suitable.

On that topic, I do have one of those for (IIRC) 3/4" blades in CXA. However, I never use it for parting. But having it and assorted HSS parting blades on hand, I have found that it's really quite useful as a grooving tool. Much easier to grind the parting blade to make a snap ring or o-ring groove than to grind that onto a standard square blank. Doing so allows me to make use of otherwise unused tools (since I started with the Sandvik). And a great fill in for when I don't have the proper insert for the Top-Notch which I used pretty much exclusively for threading, with only a handful of grooving inserts that never seem to match what I need.

I fully support gaining the skill to grind your own HSS tools. When I had slower and less powerful/rigid machines, they were by far the best option. And they still fill an absolutely essential role even with my current rigid/powerful/fast lathe when I don't have appropriate inserts to suit my needs. I absolutely would not accept losing that option, and can only offer my sincerest thanks for Harold strongly encouraging me to persevere with that skill when I was struggling (when I first came to this board). However, if you have the budget and machine, I heartily endorse the Top-Notch and Sandvik (or comparable) options available. They've made my day to day encounters with threading and parting (and once in a while grooving) into no stress events. They are expensive, but it still impresses me just how long those inserts will last. The only downside is the expense trying to acquire every insert shape or purpose (aluminum, super hard, etc) you might need, but all you really need is the main things you run across day to day. If you've acquired the skills to grind HSS, filling in the gaps is then trivial. And again, the Top-Notch in particular have stunned me with how long they last, so the expense is amortized over many many low stress applications, and I don't need an optical comparator to get the thread form correct.

Oh, and if anyone likes, I can post pics of my commercially manufactured horizontal holder for the parting blades. I acquired mine from ebay for (practically) chump change during the "great recession". I got it, a used blade, a new blade, and some inserts; all for about half what the blades cost retail. I'm far too cheap to buy such things, particularly since I don't work for pay, and so simply can't justify the expense.
Russ
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whateg0
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Re: Parting tool holder

Post by whateg0 » Sat Feb 15, 2020 7:46 am

Being able to now grind carbide inserts also opens up tooling possibilities that were previously reserved for hss. I used to use hss ground tools for things like snap ring grooves. Now I have a couple of carbide inserts for that. Not a huge advantage mind you, but it allows me to run the lathe at a higher spindle speed and put grooves into harder materials.

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GlennW
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Re: Parting tool holder

Post by GlennW » Sat Feb 15, 2020 9:03 am

SteveM wrote:
Thu Feb 13, 2020 10:55 pm
I have a pile of GTN2 parting inserts.

I had a toolholder like this:
gtnB.jpg
but the problem is that the lower portion is not well supported and it actually snapped off.

Tool was cutting great - right until it wasn't cutting at all.

I don't get why they just don't make the underside larger - it's not like it's going to get in the way.
You'll find that it is more of a rigidity issue with the machine causing the breakage than it is a design issue with the tool holder.

That is why parting on a larger more rigid lathe is effortless in comparison with bench top lathes. The cutting load on the tool is far more stable and consistent.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

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NP317
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Re: Parting tool holder

Post by NP317 » Sat Feb 15, 2020 11:58 am

My all-time favorite cut-off tool arrangement is those built into the Hardinge collet lathes.
The assembly is mounted above the spindle, right at the collet opening.
This makes the cut-off operation the most rigid possible. Cuts like butter with a HSS tool.
Wish I had one...
RussN

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SteveM
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Re: Parting tool holder

Post by SteveM » Sat Feb 15, 2020 3:01 pm

NP317 wrote:
Sat Feb 15, 2020 11:58 am
My all-time favorite cut-off tool arrangement is those built into the Hardinge collet lathes.
The assembly is mounted above the spindle, right at the collet opening.
This makes the cut-off operation the most rigid possible. Cuts like butter with a HSS tool.
Wish I had one...
RussN
I thought about how to make one to retrofit to another lathe. Whenever I see a video where one of those is being used, it's so quick and easy.

Steve

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SteveM
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Re: Parting tool holder

Post by SteveM » Sat Feb 15, 2020 5:54 pm

Shameless plug.

I have some blade type parting tools I can't use.

Here's the link:

https://www.chaski.org/homemachinist/vi ... 8&t=109165

Steve

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Re: Parting tool holder

Post by RSG » Mon Feb 17, 2020 9:03 am

Steve, Glanze makes a parting tool like you are after with a 20mm blade and it will fit the AXA size tool post holders.
Vision is not seeing things as they are, but as they will be.

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SteveM
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Re: Parting tool holder

Post by SteveM » Mon Feb 17, 2020 5:43 pm

RSG wrote:
Mon Feb 17, 2020 9:03 am
Steve, Glanze makes a parting tool like you are after with a 20mm blade and it will fit the AXA size tool post holders.
I can find it on their web site, but there are no prices, probably because they don't sell direct.

All the vendors I can find are in Europe.

Do you have a link for a US-based vendor?

Steve

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