bobnolathe
Plastic
- Joined
- Jun 9, 2007
- Location
- north carolina
This is another item about cutting tapers on the lathe. (taper 002.jpg(65.8KB) ATT 00003.htm(477bytes)) It is different in having a couple of ideas that I had not seen before. This set-up can be removed from the lathe and replaced without changing the settings,it does not require changing tailstock settings, only one measurment is required, and it works.
When the tailstock is set over to cut a taper the center of the work rotates around the lathe center point, digging a circle out of the countersink hole and the edges of the work ride on the sides of the point, often damaging it. In place of a 60 degree center use a single ball from a ball bearing set. Make a socket for the ball in the tailstock holder by drilling a countersink and then opening this with a ball nose milling cutter. This forms a hemispheric pocket with a small dimple in its base that help hold lubricant. Place the ball in this socket. The ball should be the same size or smaller than the socket. Small diameter turnings work best with a smaller ball. The work at the headstock can be held by a 60 degree point as there is no rotary movement, only angular displacement. If the work has a large a ball joint may be used here also. The ball holder for the tailstock is bored into an insert fitted into boring head . (taper001.jpg(61.3KB) ATT00003.htm (477bytes)) Or a tool holder can be made with a dovetail slide that adjust by a threaded shaft. Both methods provide sensitive adjustment and can be removed and replaced without changing settings. Duplicating a taper from an existing part is done by mounting the pattern between center s as the work to will be held when the taper is cut. Using a dial indicator adjust the left side of the pattern taper to be parallel with the lathe bed. The pattern needs to be reversed, end for end, from the direction the taper is be cut, (taper004.jpg(59,3KB) Att00035.htm477 bytes)). Cutting is done by traversing the apron, not be moving the compound. Making a taper to specs rather than a pattern requires knowing the amount of set-over and lenght of the taper. Note that making duplicate parts, using the same settings, will only work if the parts are all the same length This system allows lathe speeds high enough to make carbide inserts happy and give a nice finish. (Taper0005.jpg(63.7KB ATT0043.htm(477bytes))
When the tailstock is set over to cut a taper the center of the work rotates around the lathe center point, digging a circle out of the countersink hole and the edges of the work ride on the sides of the point, often damaging it. In place of a 60 degree center use a single ball from a ball bearing set. Make a socket for the ball in the tailstock holder by drilling a countersink and then opening this with a ball nose milling cutter. This forms a hemispheric pocket with a small dimple in its base that help hold lubricant. Place the ball in this socket. The ball should be the same size or smaller than the socket. Small diameter turnings work best with a smaller ball. The work at the headstock can be held by a 60 degree point as there is no rotary movement, only angular displacement. If the work has a large a ball joint may be used here also. The ball holder for the tailstock is bored into an insert fitted into boring head . (taper001.jpg(61.3KB) ATT00003.htm (477bytes)) Or a tool holder can be made with a dovetail slide that adjust by a threaded shaft. Both methods provide sensitive adjustment and can be removed and replaced without changing settings. Duplicating a taper from an existing part is done by mounting the pattern between center s as the work to will be held when the taper is cut. Using a dial indicator adjust the left side of the pattern taper to be parallel with the lathe bed. The pattern needs to be reversed, end for end, from the direction the taper is be cut, (taper004.jpg(59,3KB) Att00035.htm477 bytes)). Cutting is done by traversing the apron, not be moving the compound. Making a taper to specs rather than a pattern requires knowing the amount of set-over and lenght of the taper. Note that making duplicate parts, using the same settings, will only work if the parts are all the same length This system allows lathe speeds high enough to make carbide inserts happy and give a nice finish. (Taper0005.jpg(63.7KB ATT0043.htm(477bytes))