I found my iscar parted off great with the main carriage locked and the longer stock supported with a centerYou have chatter, could be stock too far out, lathe not rigid enough or blade past its best and not holding the insert securely or I suppose just crap inserts.
This would be my first thought too... Since you've tried a few different things, and good parting inserts just glide through metal... Also is the chuck bellmouthed, it could be that the stock isn't held properly right through the Jaws.Is the stock inn the chuck flexing.
Have you tried with a dead center
Have you tried incressing the speed and force ie are you running the speed fast enough and driving the blade in, mine seems to love speed and force. I know it goes agains everything i have read about parting, but it works for me, with an old Colchester MasterView attachment 320828I wanted to get some decent quality inserts and went with the shop-apt uni-tip branded GTN2's, as Id had good results with there other stuff.
AP200 UM25 Part-off - Parting Insert 2.2mm PVD Coated for General Use
Carbide Insert for Parting 2.2 mm wide PVD Coated for Steel, Stainless & general use type AP200 UM25 by Associated Production Tools Ltdwww.shop-apt.co.uk
Cant get them to cut. Its on centre, Ive tried plus and minus. Does the swarf in pic tell anything?
I still have my last useable chinese gtn2 in other end of the blade, its chipped, but it cuts ok with decent swarf wheels coming off. This bar is just mild steel. These apt inserts have much less top rake than the fragile chinese ones.
I had problems earlier in the year, the Iscar blade and inserts were just as stubborn, lots of chatter and wouldnt cut properly, until I learnt to wind them in harder... Trird that.
Any ideas?
Perhaps you should just stick with the Chinese ones?View attachment 320828I wanted to get some decent quality inserts and went with the shop-apt uni-tip branded GTN2's, as Id had good results with there other stuff.
AP200 UM25 Part-off - Parting Insert 2.2mm PVD Coated for General Use
Carbide Insert for Parting 2.2 mm wide PVD Coated for Steel, Stainless & general use type AP200 UM25 by Associated Production Tools Ltdwww.shop-apt.co.uk
Cant get them to cut. Its on centre, Ive tried plus and minus. Does the swarf in pic tell anything?
I still have my last useable chinese gtn2 in other end of the blade, its chipped, but it cuts ok with decent swarf wheels coming off. This bar is just mild steel. These apt inserts have much less top rake than the fragile chinese ones.
I had problems earlier in the year, the Iscar blade and inserts were just as stubborn, lots of chatter and wouldnt cut properly, until I learnt to wind them in harder... Trird that.
Any ideas?
He probably is, just a different name on the boxPerhaps you should just stick with the Chinese ones?......
I can get any working, it is the longevity that I seek and in that there are vast differences between brands...
I know hood gets great results with the Iskar ones but your lathe is smaller I believe?
That little tit on the face tells you that you are not quite on dead centre . . follow it closely to see if it is above or below the cutting tip and make micro adjustments till it is gone .Very happy with the tool and it's set up now.
View attachment 321547 View attachment 321548 View attachment 321549
Cut the eye off the needle and use a fine drill in the tailstock chuck to drill a hole in a bar that fits the lathe chuck I tired alu but the drill grabbed & snapped .ok thank you I shall have a go at that.
A darning needle was too thin to grip in my chuck.
I shall put the tit bit back in the chuck and see if the tool tip is below or above the tit to start.
Hood ,It may be on centre, when parting the metal tends to shear off when it is nearly through and usually the extra is on the parted bit but it will also leave a mark on the part in the chuck, sometimes slightly recessed.