Long axis screw in the CNC processing will encounter many problems and we will answer the questions about how the CNC lathe machining factory process long axis screw.
The reason why this workpiece is called long lead screw is that its own length is relatively long and is relatively twenty times longer than its diameter so it can be called a long axis. Due to its slender characteristics, in the CNC machining process there may emerge bending and eccentric vibration phenomenon and deformation due to heat, resulting in cutting inaccuracy. It will also exert impact on the pillar, making it not smooth enough. Here are ways to improve processing quality.
You can make one or more support devices, place them under the long axis workpiece so as to give the long axis a stable support and the original length of a few parts will greatly reduce the length of the workpiece, then you can use the CNC machining of ordinary workpiece method to process as the workpiece is limited to the support frame, even if the length itself is large, and there will not emerge bending eccentric vibration and other consequences.
Another method is to add a sleeve to the workpiece, and the sleeve is fixed, this method makes the workpiece confined to the sleeve force, its length calculation is also calculated by dividing the length of the exposed sleeve into two and the length of the workpiece is made smaller, thus facilitating the processing. And we will offer you excellent CNC lathe service.
After finishing the above two measures, you can also consider a variety of ways to dissipate heat, such as choosing a good cutting fluid or placing strong ventilation equipment.
Screw backlash will cause the following undesirable problems.
The processing size is not stable: given the normal processing parameters, the processing size is either large or small and in different locations processing size is not the same.
Surface is super rough: Z-axis screw is too loose, the spindle will swing left and right up and down.
The processing right angle has been rounded: less than the specified position to start converting the next instruction.
CNC machining circle is made into an ellipse: ellipse is divided into 45 degrees ellipse (x y axis gap is too large) 90 degrees ellipse (see normal parameters in which axis size is not in place).
Processing out of the wavy pattern: screw may have card beads, bearings have entered the debris, screw clearance is too large.
Milling shaped holes will be taper: CNC machining products are combined with micro-vibration, the nut and then screw will rotate.
The screw-nut pair of CNC machining center is a rotating device with low movement friction and is easy to eliminate the rotation gap. It has the advantages of low wear, high efficiency, high precision and low temperature. It has brought tremendous help to the performance improvement of the transmission system.
Do all screw rods of CNC machining centers need to be preloaded? The reason for preloading is to prevent the ball from sliding off, but not all screw rods need to be preloaded. The higher the precision of preloading, the greater the load capacity. Specifically, it depends on the user's needs to select the level of preload.
What are the preloading methods?
1. Double nut threaded preload
The relative axial position of the two nuts is adjusted by round nuts, which is one of the pre-tightening methods.
2. Double nut washer type pre-tightening
This method is relatively simple and widely used. This is the way to add a gasket between the double nuts. The manufacturer can adjust the pre-tightening force according to the customer's requirements, and it is easy to install and remove.
3. Single nut variable lead self-preloading
This kind of pre-tightening method is to produce a lead mutation in the middle of the inner thread of the nut, so that the pre-tightening can be realized by causing the balls at the left and right ends to be axially displaced after assembly.The main purpose of eliminating the axial clearance of the screw nut pair of CNC machining center is to improve the transmission accuracy and rigidity.