Design and Fabrication Of Concave Attachment For Shaper Machine

Design and Fabrication Of Concave Attachment For Shaper Machine

In this article we will see brief information about ” Design and Fabrication Of Concave Attachment For Shaper Machine “.


A concave attachment is a versatile one to cut concave-convex profiles. A set of rotating plates have T-slots for the T-bolts that hold the boring bar. These plates are rotated by a train of gears. The bar is held roughly yet free enough to rotate. When the tool is built, the boring bar is first clamped with both pivots at lead centre. So, the tool describes a zero radius when the crank is turned.

At this time, one set up pin hole is drilled in each of the rotating plates, as indicated so that the pin touches the boring bar. Then to set the tool, for a desired radius, it is merely necessary to place a piece of flat stock the same thickness as the desired radius between the bar and the set up pins while securing the bar in position. At this point, data the flat stock and set up pin can be removed.


The concave attachment is fixed to the carriage of the Shaper. The compound rest that is locked solid with its base is removed and the attachment is fixed on the cross lied of the carriage with its axis parallel to the Shaper bed.

The work is secured rigidly in a chuck. By the concave-convex movement of the boring bar, the material is being removed. This attachment is used to produce contour profiles and round balls.

cocave attachement for shaper mechanical project
cocave attachement for shaper mechanical project


In recent years, new fabrication techniques have been developed to satisfy the technological demands. Moreover, emphasis is stressed on attachments.

Attachments are used in various fields and machines depending upon the needs to be fulfilled and mode of operation. An attachment eliminates the purchasing of a new unit which serves the same purpose. For example, a Shaper occupies a place opposite to that of a milling machine, the ten machines mainly used to produce cylindrical and plain surfaces respectively. By implementing an attachment to a unit, the capacity of the unit can be increased which is very economical.


The worm wheel is rotated with the help of a worm shaft. Rotating plates with T-slots that hold the boring are screwed to the worm wheel. The worm wheel in turn is screwed to its base with a simple gear train. The rotary motion is imported to the blank through two spur gears and an intermediate gear namely “Idler Gear”.

The idler gear serves to keep the rotation of rotating plates in the same direction. The worm shaft is rotated in clockwise direction, the boring bar machines a contour profile in the clockwise direction and vice versa. Thus a concave-convex profile is machined by boring bar by simultaneous engagement of the two plates.


When the worm shaft is rotated in a clockwise direction, the worm wheel rotates in the clockwise direction and vice versa.
Idler gears are used to rotate the rotating plates in the same direction. When the boring bar is bolted to only one of the ‘I’ slots in the rotating plate and when the crank is turned, the material is removed at a certain radius depending on the extension of the boring bar. When the boring bar is bolted to the T-slots provided in the rotating plates and when the worm is rotated, the boring bar described a concave-convex profile. This movement of the bar is used to produce spherical balls also.


  • The unit is compact in size.
  • Less maintenance is essential
  • The unit gives long life with proper alignment of gears.
  • Jobs can be easily handled in this unit.


  • Concave and convex profiles of desired radius can be easily turned.
  • Round balls can be produced.

Sachin Thorat

Sachin is a B-TECH graduate in Mechanical Engineering from a reputed Engineering college. Currently, he is working in the sheet metal industry as a designer. Additionally, he has interested in Product Design, Animation, and Project design. He also likes to write articles related to the mechanical engineering field and tries to motivate other mechanical engineering students by his innovative project ideas, design, models and videos.

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