Have you ever met such situation: when you use a cnc cutting tool to process a material with a certain cutting parameters, but the working effect is not so good as what you thought? Your first reaction may be that there is something wrong with the quality of the carbide inserts? Is the parameter settings are unreasonable? And with your doubts, you will ask the supplier to find out the reason. Or sometimes if you don’t have time to dig deeper, and just let your purchaser go to find a new reliable supplier. This happens from time to time.
Complaints from one of our cnc cutting tools end users.
Recently there is similar cases happened on one of my milling inserts end users, who bought LNMU0303 inserts from us on last November. That day I intend to ask for her new order request, but she told me she was a little disappointed, as the quality of the second part was not the same as the first one, she can’t work with them as well as the first part. She mentioned used to work with them about 3 hours in roughing, but the second part was about to 1 hours maximum.
Through her speech, I can fully understand her sadness. In order to solve this problem for her better and timely, I simply inquired about whether the inserts model, grade, workpieces and setting parameters are same for two times machining. Is there any coolant during processing? Besides, I also let her to try to provide the whole processing video and the worked inserts pictures for checking. The other day she offered all information: the insert is for processing plastic mold, material hardness have HRC46-48, cutting parameters are Dz=0.7 mm, feed=2500 mm/min, spindle speed=800rpm.
After checking with technician, we found the main reason for this problem was that the number of revolutions of the spindle was too low, which caused the chips to stick to the tool easily, and the processing time became shorter. And we checked the former record and found she purchased different grade of inserts, so there is possible her worker mistake used the insert grade, that’s why two times insert service life is different. In the following we suggested her to adjust spindle speed into 1500rpm, and machining without coolant. After one week, we received her feedback and she told with our parameters the got so much better and said thanks to me.
The methods to use the carbide inserts suitably.
Through this experience, I realized it’s very important for us to provide the professional and timely after-sales services for our customers. And it’s more necessary to train them how to use the carbide milling tools correctly.
Following are our basis cutting data for high feed milling inserts.
P(for steel processing):
Vc=150(120-200)m/min
fz=0.25(0.10-0.35)mm
M(for stainless steel):
Vc=140(120-160)m/min
fz=0.2(0.10-0.30)mm
K(for cast iron machining):
Vc=180(150-200)m/min
fz=0.2(0.30-1.50)mm
The parameters are only a reference, the specific parameters need to be comprehensively determined according to the working conditions, material hardness and machine rigidity, etc.
Besides, when designing or modifying a new machining plan an existing machining plan, it is recommended that cycle time, tool life, part quality and surface finish be the main goals. Then make it specific, graded and quantified to form testable and acceptable indicators.
If the law of the cutting force is known, the direction of the cutting force can be selected, thereby improving the clamping rigidity of the part. In addition, considering the method of reducing the depth of cut, the radial force can be transformed into an axial force direction.
Last but not least, choose a tool with a main deflection angle, increase the feed rate, increase the chip thickness, increase the cutting speed, etc.
Hope you have learned a lot from above article. Any doubt, please feel free to contact Melody at +86 177 7337 8761.
