23 / 12 / 2022 | Videos

Making a polygon lathe cutter mechanism



In many cases, a processed piece on the lathe needs to have some shapes in some parts of it not cylindrical shapes that a conventional lathe cannot create.

These shapes can be square, hexagons and generally polygons. These shapes are commonly seen in normal metallic pieces like screws, tool nuts, drive shafts and other. Therefore, for their making we use the lathe and then we make the spots that they have angles using other machines like the milling machime, the metal shaper, the surface grinder and other. Thus, in order to avoid using other machines which simultaneously do other tasks as well as saving some time and having greater accuracy, we decided to make an attachment on the lathe that we already use to make polygon shapes without the need to use any other machines.

Initially, we "borrowed" motion from the leadscrew for our mechanism which is responsible for cutting the thread on the processed pieces on the lathe. This screw which works as a motion transmitter is connected with the norton gearbox that is responsible for cutting various threads meaning that if we set the speed accordingly we can create threads in various shapes. Furthermore, using this gearbox we control how many spins the lead screw can make according to a full spin of chuck. 

After taking motion from the lead screw we transmitted it on an axis through two gears with 2:1 ratio. This axis transmits the rotary motion on our cutter. Also, it has cross shaft transition in its edges so while crossing it is enabled to move forward and backward the same time.

Also, the axis that is connected   with the cutter can be moved while spinning at right and left.
In this way, while our cutter is spinning the attached piece to chuck is also moving right and left along it as well as in front of it or behind it and vertically towards it.

Afterwards we made a spindle, on which we placed a cutting tool that has three carbide cutting tools on it. Having this tool combined the gears, we can create an octagon, heptagon, hexagon,pentagon and a square.
Using various other cutting tools and gears, a lot of other polygons can be done. The shape is made on the piece while the piece is moving against the rotation of the cutter which removes  material from the piece.

Check out our Tools ans Plans Here




















...
Read More