Trouble-free and successful parting off - Tips film #37
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- čas přidán 28. 10. 2015
- Often being the most challenging and also the final operation, you can't afford failing when parting off. Watch this episode for tips on how to make parting off trouble-free and successful.
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Transcript:
Parting off is one of the most challenging applications in metal-cutting and always used on turning centres, sliding head lathes and multi-spindle machines with a bar feeder. It is often one of the final operations and as a lot of time has already been invested into the almost-finished component, a tool failure at this stage can prove extremely expensive. Therefore it is worthwhile focussing a little extra on this area; and in this episode we will discuss the main guidelines to ensure trouble-free and successful parting off.
There are three main stages of the parting plunge, including the main long cut through the bar, the approach toward the end of the cut and the short stage just before reaching the component centre. As the tool is fed deeper, chip evacuation becomes essential but even if good external-coolant setups are used, chips can still get in the way to cause heavy loads and poor component finish. Internal, over- and-under, high precision coolant channeled through the tool provides the highest machining security. With over-coolant taking care of chip control and under-coolant prolonging tool life and increasing surface speed by between 30- and 50%.
Effective parting systems include inserts with a specially-developed channel to ensure coolant reaches the right position on the cutting edge. The geometry can then fold and curl the chip, making it narrower than the groove so that it evacuates without becoming trapped.
We recommend starting with the first-choice grade and recommended speeds and feeds for the material being machined. A speed that is too low can form a built-up edge on the insert, while a feed that is too low increases time in cut and risks more insert flank wear.
As the tool reaches the component centre, cutting speed decreases below the recommended value, causing a built-up edge and high loads on the insert. To avoid insert breakage and poor chip control, reduce feed by 50-75%, two millimeters before the centre. This small change in programming provides a large increase in tool life.
Always set up the tool with the shortest possible overhang, the recommended maximum being 8- to-10 times the insert width. To avoid tool breakage and rapid flank wear it is also essential to maintain the centre-height setting to a tolerance of plus or minus .1 of a millimetre or .004 of an inch.
So there you have it, a short guide to getting the most from your parting-off operations. To summarize, here are three main points to remember:
- use the first-choice tool- and cutting data recommendations
- use high precision coolant whenever possible
- always reduce feed at the component centre - Věda a technologie
muy bueno, gracias
Cool content
Hi Sandvik, thank you for this video, how about using G96 on parting as well?
Expected roundness after parting off tube part
Please help me to solve ovality when parting off a tube part in 2axis cnc lathe, our part spec OD:189.80-189.90mm ID:175.1-175.2mm thickness 8.54-8.56mm but ovlaity comes 0.2mm in OD and ID
I love the videos! they are so great! can you show by examples how to use the speed charts?
I have a Qcut tool holder but I'm really bad when I set the propper feed rate and spéed. I feel I go too slow than I could, but if I increase a little then it goes too fast and makes a horrible noise.
In my workshops handbook (verkstadshandboken), it recommends (for example), Material group 4 (seghärdningsstål) Alloy steel = 0.05 feed @ 200mm/rev Material group 23 Aluminium = 0.05 feed @ 450mm/rev
I hope this helps.
Dave Smith can I buy that handbook? I have problema with the licencia of my inserts
Ro Cuevas Just get the data from their website.
The website has gotten a LITTLE BIT better than it was last year.
Side note, regardless of what your rep says, you really need high pressure coolant to get those chips out of the cutting zone.
I have been less than impressed with this system as far as insert life is concerned.
Not shocking to me considering that's what they make the vast majority of their money on.
I find Iscar grooving/cutoffs to just WORK and Sandvik...not so much and for a bit less.
Not throwing Sandvik under the bus, but it is what it is.
When someone calculates the speed, I have a question because the radii is Zero, what diameter should I use? What about interrupted cutting?
Program for constant surface speed with a G50 cap.
С субтитрами эта анимация особенно прекрасна
Please help me to solve ovality problem when parting a pipe in CNC lathe machine
Hello Vignesh,
what material you machining and what geometry do you used?
QD system have you tested pure Nickel 270 not having luck no interruption 2" diam solid part 1125 grade keeps plugging up the top coolant hole
+onefugowie
Hi!
It is difficult to give you a perfectly optimised suggestion without more information about your specific operation. But it seems like you need a geometry that gives shorter chips. Try geometry -CL. Higher coolant pressure will also help to evacuate chips.
Best regards
Staffan Lundström, Product manager P&G, Sandvik Coromant
+Sandvik Coromant thanks for info will look into CL it works well don't get me wrong but when it does seam to fail its plugged the top hole...I think changing insert sooner maybe its loosing chip control after certain amount of parts
No matter what parting tool I use, they refuse to cut.
If I push hard, motor stall or worse.
I don't understand this tool geometry and why it doesn't work.
The most important thing is to see if the cutting edge passes by the center of your part, or just a little under it.
But if it goes upper the center, the insert will break