Which parting tool for a Boxford?

[Beanwood]

I'd like a parting tool for my Boxford CSB.

Tool height to centre appears to be 12mm - and I don't have a QCTP or any parting holders currently.
I've seen a couple of interesting things on Chronos - but would like to know what you all think - as I really have no idea, and don't undrstand how they measure things - with a 1/2" shank, but 3/4 blade for example, which is presumably too tall for my little thing!

Chronos suggested
or
Cheap and cheerful
or
'Professional version'

 

[Agroshield]

None of the above, especially the middle one.

This would be high on my list:

SLTBN Part Off Blade Tool Blocks with Blade - Arc Euro Trade

SLTBN part off tool blocks with NCIH self-locking parting blades and GTN inserts. Sizes: 6-16mm shank, blades for 2mm & 3mm GTN inserts

www.arceurotrade.co.uk

 

[Kram]

As above.

HSS blades like to shatter and go flying when they get overloaded. Theres a very real risk of injury with them! If a carbide lets go it is normally just the tip. The holder and blade are somewhat more flexible, although they can still be damaged.

GTN2 are good for a small lathe, generally they are sharper and slightly less durable than others, which suits a small lathe - lower cutting pressure and less rigidity required.

The wider 3mm inserts take a lot more force and require rigidity, they dont work too well on mine.

 

[Seadog]

I used both GTN2 and 3 on my AUD.

 

[Beanwood]

None of the above, especially the middle one.

This would be high on my list:

SLTBN Part Off Blade Tool Blocks with Blade - Arc Euro Trade

SLTBN part off tool blocks with NCIH self-locking parting blades and GTN inserts. Sizes: 6-16mm shank, blades for 2mm & 3mm GTN inserts

www.arceurotrade.co.uk

Yep - thought that about the middle one - but it was the right price

I used both GTN2 and 3 on my AUD.

GTN2 and 3 being the width of the cutting tip presumably?

I was slightly put off the insert type by youtube clips of tool holders bottom lip breaking when the inserts snap out.


I did like the look of the chip breaker ones on Chronos - are these a no as well? Chronos chipbreaker

 

[Agroshield]

GTN2 and 3 being the width of the cutting tip presumably? ...chipbreaker ones on Chronos

Yes, the 2 and 3 are ther kerf width in millimetres. You need a different holder for each width of insert; yo ucannot put a 2 or a 3 indsert into the same holder.

A lot of what will suit will depend on the diameter of what you are parting. In your original post, the first one from Chronos has a scalloped holder, giving a maximum diameter. That design provides good support under the blade, but it is forever fixed.

The Chronos chipbreaker blade here is nice because it has a vee ground into the top, so will curl the chip, making it thinner than the groove being cut, hopefully leading to less jamming. It is only 10mm high though, so if it sticks out too much it will bend downwards under cutting forces. You can slide it in and out of the holder to give best support for a specific diameter.

The insert holders are usually 19-20mm deep, so a lot stiffer. They can also be slid in and out.

The machine holding the parting blade needs to be in reasonable condition as well for success. Try to part off as close to the chuck as possible, so the workpiece does not deflect. Bell-mouthed chuck jaws do not help. Lock the carriage. Try to use with minimum compound slide overhang. Dial the blade in with the direction of travel.

Be prepared for something to break. Buy two blades - that gives you four insert pockets to hone your craft with. Don't worry about the money. Better to use it on developing a skill than pouring it down your throat.

 

[RichardM]

Your original post - I'd go for the soba one although it it flat and when you regrind the blade you will have to alter height, it supports the blade fully.
If you want inserts - gtn2 means you put less strain on the screws, check what the design depth of cut is for the respective holders between 2&3.

 

[Misterg]

I've owned all of the ones suggested so far. (Yes, even the 'christmas cracker' version that's the middle one in the original post - it is ****tier than you can imagine.)

Hands down, the 'best' is the GTN2 one suggested by @Agroshield.

Best = cuts quickly, without drama, lasts longest, copes with decent diameters, doesn't twist off line.

I bought spare inserts with mine, but I don't think I've ever needed to change one.

(This is on a mini lathe, by the way )

 

[not done it yet]

None of the above, especially the middle one.

Mine is similar, but much better than that.

It sits on the rear of my cross slide on a separate (rigid) toolpost. It works faultlessly on anything except for the odd job which really needs a carbide tip.

I don’t buy much (if anything) from Chronos. Arceuro almost all the time. But I’m just a hobbyist, not a commercial set up.

 

[Kram]

One thing to note is the Arceuro set is quite cheap for the parting block, blade and insert. If you buy seperately they will cost a bit more, so its a good price.

However the Arceuro sets are for a 19mm high blade, where as generally 26mm are the standard, 32mm for larger lathes with more centre height.

Blade height will make a reasonable difference to rigidity at deeper parting depths. This will complicate it a bit as you say you dont have a QCTP and it may be a lot of effort to get on centre... I'd highly recommend you get a QCTP, it saves so much time and messing about.

The 250-111 sort have a 14mm shank slot however easily enlarged to 16mm, lets you use bigger tools and I think I get better results than my lathe should, as a result.

In my case I bought a similar set from RDG with 26mm blade, this thing.

Indexable Parting Tool 2mm x 26mm Blade (16mm shank) - RDG Tools

Indexable Parting Tool comes complete with a 2mm thick blade (1 tip included) unit will part upto a 4″ diameter bar 16mm shank a quality tool 5056685106471

www.rdgtools.co.uk

 

[Beanwood]

I'd highly recommend you get a QCTP, it saves so much time and messing about

Well up on my wish list- and it is almost Christmas!

 

[Beanwood]

OK - the deed is done - GTN 2 and GTN 3 blades with the Arceurotrade holder (Same holder for both seemingly).
I can always buy another later if I don't like it

 

[Guineafowl]

Can I be awkward and say I have all three on my AUD?

1. This type for most things. Much more rigid and positive clamping means no parting off disasters.

2. Blade version of above only for longer reach.

3. Hss for custom stuff - left or right bias to leave a neat finish, or for making hose barbs. Ground thin for circlip grooves.

 

[striker]

Can I be awkward and say I have all three on my AUD?

1. This type for most things. Much more rigid and positive clamping means no parting off disasters.
View attachment 476037
2. Blade version of above only for longer reach.

3. Hss for custom stuff - left or right bias to leave a neat finish, or for making hose barbs. Ground thin for circlip grooves.

I have the no.1 type. It's great but won't work on larger diameters.

 

[Guineafowl]

I have the no.1 type. It's great but won't work on larger diameters.

I got the no.1 after ruining both ends of a quite expensive Cutwel GTN2 blade type. Problem is, its toolholder is clamped into another toolholder, so there’s a lot of sideways stick-out. Not much warning - an unhappy noise, then - BANG! - the part, insert and blade all ruined.

I’ll happily part off under power with no.1 type all day, but no.2 type always gives me the heebies.

 

[smashweld]

HeebieJ Parter V2?

(was only for some nylon bushes)

 

[Beanwood]

The purchase arrived late last week, and yesterday I finally had chance to try it.
OMG - It's one of those tools that makes you think why didn't I buy one ages ago.
Used many of the tips from above - not too much sticking out, gib strips snugged up, cut near the chuck etc. and it performed flawlessly, cutting 40mm steel rod once I had centre height worked out accurately, which was indeed a bit tedious.

 

[Guineafowl]

once I had centre height worked out accurately, which was indeed a bit tedious.

Rotate tool 45deg left, use corner of parting tip to face a bit of brass, start low, tweak tool upwards until nib disappears?

 

[not done it yet]

Rotate tool 45deg left, use corner of parting tip to face a bit of brass, start low, tweak tool upwards until nib disappears?

Then raise it a tiny amount to take into account the far heavier load, compared to near zero cutting speed at the centre nib, imposed on the tool tip when actually cutting full width and at possibly higher surface cutting speed and with extra stick-out.

 

[Guineafowl]

Then raise it a tiny amount to take into account the far heavier load, compared to near zero cutting speed at the centre nib, imposed on the tool tip when actually cutting full width and at possibly higher surface cutting speed and with extra stick-out.

Makes sense.