There are several different methods to use when machining collets to your desired size. Please note that it’s very important to seat a collet into the spindle prior to machining. Expand the collet between .003”-.005” depending on how much the inside diameter of the part varies. Listed below are a few options to choose from:
Insert the assembled collet into the spindle and seat it by putting a ring or hose clamp over the unmachined diameter of the collet. Next, activate the draw tube. Remove the expanding screw completely from the collet. Take an extra expanding screw and cut off about .250” of the thread. Insert the shortened screw into the collet and manually expand the collet to the desired size for machining. Having a shorter screw will allow you to manually expand the collet without the screw bottoming out into the rod. Once machined, replace the screw with the original expanding screw and tighten it securely into the rod. The collet is now ready for use.
Insert the assembled collet into the spindle. If the collet permits, tree pan a groove into the face of the collet and insert a turning ring (we can provide) into the groove. Seat the collet by expanding it on the turning ring. At this point, the collet should be expanded between .003”-.005”. Machine the collet to your desired size. Remove the turning ring. The expanding collet is now ready for use.
Insert the assembled collet into the spindle. Seat the collet by putting a ring or hose clamp over the unmachined diameter, and activate the draw tube. Bring the draw tube to the forward position and back out the expanding screw so that only a few threads are engaged in the rod assembly. The expanding screw should be sticking out from the face of the collet by at least a ½”. Drop the hydraulic pressure on the collet closer so that the draw tube moves very slowly. Activate the collet closer to draw back. Depending on the stroke on of the draw tube on your machine, the expanding screw should not engage into the taper of the collet. If the expanding screw does engage into the taper, abort this procedure and manually turn the screw of the expanding collet screw into the collet so that you obtain between .003”-.005” of expansion. Machine the collet to your desired size. Bring the collet closer to the forward position and screw the expanding screw securely back into the collet. Slide your part over the machined collet. The collet is now ready for use.
The above are just a few options that we recommend. The following are some links to videos for your review. Need more info? Do not hesitate to contact us to go over your specific applications. 800-423-5145