- Thread starter Kram
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Do you have power feed on the cross slide? if so, part off under power with the feed set appropriately. The feed is so much more consistant and the lathe doesnt get scared and bottle it causing jolts and you can concentrate on getting coolant where its needed at the coal face of the parting tool to remove the heat generated.
Screwdriver
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I hate parting off. It is always fraught but you get vastly better results with the following:
Correct set up. Tool height should be bang on, stick out needs to be as minimal as is possible (to reach the middle) and the tool needs to be dead square.
Begin the cut then widen slightly by moving the saddle a few thou, this should give you a little bit more relief. Parting off needs relatively high constant pressure on each cut. Dive in, get the cut going then back out, lubricate/cool as required.
If you get chatter, change speeds and if all else fails, use the starting cut as a guide for hacksaw. Never, ever use a hacksaw on a spinning part. Only ever wear gloves when working on a lathe if you're really sure you have too many fingers.
I often used to have to cut off parts with a hacksaw but more recently, after a fair bit of practice with the above, it's been getting easier. Seriously though, don't get blasé about fling or sawing on a spinning lathe. There's a lot of power there, a fair bit of momentum on even a medium size lathe running a four jaw and if it gets a grip on you, it will not stop until it has ripped something off.
Correct set up. Tool height should be bang on, stick out needs to be as minimal as is possible (to reach the middle) and the tool needs to be dead square.
Begin the cut then widen slightly by moving the saddle a few thou, this should give you a little bit more relief. Parting off needs relatively high constant pressure on each cut. Dive in, get the cut going then back out, lubricate/cool as required.
If you get chatter, change speeds and if all else fails, use the starting cut as a guide for hacksaw. Never, ever use a hacksaw on a spinning part. Only ever wear gloves when working on a lathe if you're really sure you have too many fingers.
I often used to have to cut off parts with a hacksaw but more recently, after a fair bit of practice with the above, it's been getting easier. Seriously though, don't get blasé about fling or sawing on a spinning lathe. There's a lot of power there, a fair bit of momentum on even a medium size lathe running a four jaw and if it gets a grip on you, it will not stop until it has ripped something off.
I had a warco style lathe for a while and it looked nice but could not pull the skin of a rice pudding....different league to a boxford
Hood
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Is it an inserted tool or HSS?
Inserted parting tools like to be fed pretty hard and when they are going right the swarf comes off in nicely coiled bits kind of like a clock spring, then again some Inserts are poor and do not cut well.
A parting tool needs to be on centre although some manufacturers actually state they should be slightly above centre, 0.1mm or so.
You lathe however may not have the guts for a high feed when parting, especially if it is a VFD controlled one as yours seem to be .
Inserted parting tools like to be fed pretty hard and when they are going right the swarf comes off in nicely coiled bits kind of like a clock spring, then again some Inserts are poor and do not cut well.
A parting tool needs to be on centre although some manufacturers actually state they should be slightly above centre, 0.1mm or so.
You lathe however may not have the guts for a high feed when parting, especially if it is a VFD controlled one as yours seem to be .
God mode restorations
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I am reading these posts of intrest. As I will be having a go at parting once I get the correct tool. Is it ok to part from the front post as I have seen a lot of videos with people using rear tool posts to part.
Screwdriver
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Because it is such a critical setup and an often used procedure for production work, it can be handy to have a parting off tool permanently fixed to the cross slide which frees up the compound slide for your other tooling.
Plus of course, it gives you the opportunity to buy another toy
brightspark
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rear toolpost parting much better if u have a long cross slide 
http://www.practicalmachinist.com/vb/south-bend-lathes/rear-tool-post-236997/ ive got one on a myford I just bought cheap . I have a mint ml7 but wouldn't swop the slide on to it but I am swopping the clutch of it on to mine
http://www.practicalmachinist.com/vb/south-bend-lathes/rear-tool-post-236997/ ive got one on a myford I just bought cheap . I have a mint ml7 but wouldn't swop the slide on to it but I am swopping the clutch of it on to mineCurrently I've only got a front toolpost (harrison short cross slide on at the moment). If I can swing it and get my slide back far enough, I'll have a go at parting it off under power, even if I have to slide the parting tool deeper as the cut progresses.
no gloves, no jewelry, no loose fitting clothing and no long hair round machines with rotating spindles here. You can do what you like with your own fingers but I've seen the results first hand of a momentary lapse of concentration by a experienced hand.
no gloves, no jewelry, no loose fitting clothing and no long hair round machines with rotating spindles here. You can do what you like with your own fingers but I've seen the results first hand of a momentary lapse of concentration by a experienced hand.
Hood
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Not sure what is available in the small size but if you can get a block that takes a 26mm blade then it would be worth investing is quality blade and inserts. I am now using Iscar Tang style and they are simply amazing and J and L have them on special every so often, £90 incl VAT for a blade and 10 inserts.
Impressed ..the one i had would never manage that.
Any pictures??Because it is such a critical setup and an often used procedure for production work, it can be handy to have a parting off tool permanently fixed to the cross slide which frees up the compound slide for your other tooling.
Plus of course, it gives you the opportunity to buy another toy
Gritineye
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I wouldn't be using a tipped tool on a low powered lathe like that, you can hear it's not cutting cleanly.
A HSS tapered parting tool will cut much cleaner and quieter and use less power to do so.
You will get a better feel of the feed as you'll not be pushing it in so hard, grinding the tool is so simple nothing to be scared of there.
A HSS tapered parting tool will cut much cleaner and quieter and use less power to do so.
You will get a better feel of the feed as you'll not be pushing it in so hard, grinding the tool is so simple nothing to be scared of there.
Hood
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Afraid I have to disagree there , a decent insert parting tool will not require any more power than a HSS one and it will have the added benefit of the chip breaker deforming the cut material so that it becomes narrower than the groove and exits easily.
Now a cheapo parting tool insert is a different matter and the ones that do not have a positive stop are definitely to be avoided.
Now a cheapo parting tool insert is a different matter and the ones that do not have a positive stop are definitely to be avoided.
brightspark
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I make my own carbide parting tools cut from a circular saw blade and fit in a holder works a treat on any size lathe
Hood
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indy4x
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I have always hated parting off, mostly ended up in tears usually with a broken parting tool.
Bought a reasonable quality tipped parting tool and spent some time setting it up and so far it's been fine, no chatter, no more jams and feel quite chuffed. Not done it with the power cross slide yet but it's in the list of things to try out
Bought a reasonable quality tipped parting tool and spent some time setting it up and so far it's been fine, no chatter, no more jams and feel quite chuffed. Not done it with the power cross slide yet but it's in the list of things to try out
Kram
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Id like a blade parting tool if it will let me part full depth?
Do you know insert shape code for the ones you recommend? I was looking at the GTN type.
I agree about power, lathe struggles at half speed and need to be geared down, not decied the best way to do it.
Do you know insert shape code for the ones you recommend? I was looking at the GTN type.
I agree about power, lathe struggles at half speed and need to be geared down, not decied the best way to do it.
Hood
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The GTN are inserts that do not have a positive stop but some blades do incorporate one although the cheap ones do not, so not an insert shape I would recommend.
The ones I am using now are the Iscar TAG ones and previous to that I used the A2 Kennametal ones.
MSC Direct are now on to the November special offers so the blade/insert offer has finished but it will likely be on again in January if you can wait.
This is them.
https://www.mscdirect.co.uk/LAI23-02165K/SEARCH:KEYWORD/product.html
When on offer they are £82.99 plus VAT and delivery which takes the total to £105
