ME703 - Manufacturing System
Laboratory - 1
Assembly and Part drawing of Screw-Jack
Submitted To
DR. A.S.SHEYTRA BALAN
By
Rahul Rajput Lodhi
252MF016
DEPARTMENT OF MECHANICAL ENGINEERING
NATIONAL INSTITUTE OF TECHNOLOGY KARNATAKA
SURATHKAL, MANGALURU-575025
September, 2025
Abstract
A screw jack is a mechanical device used to lift or apply large forces by means of a screw
mechanism. It consists of a body, screw, nut, and handle, which together convert rotational
motion into linear motion, enabling the lifting of heavy loads with comparatively less effort.
Due to its simple design and high mechanical advantage, the screw jack is widely used in
mechanical systems such as vehicle lifting and heavy equipment maintenance.
The present report focuses on the modeling, assembly, and drafting of a screw jack using
Creo Parametric software. Each part of the screw jack was created individually using basic
modeling tools such as revolve and extrude, while special features like the helical sweep were
applied to generate the square threads of the screw and nut. These parts were then assembled
with appropriate constraints, and a detailed 2D drawing was generated with orthographic
and isometric views.
The primary purpose of this report was to gain hands-on experience with Creo Parametric,
to understand the procedure of part modeling, assembly, and drafting, and to familiarize
with CAD practices that are essential in modern mechanical engineering design.
Steps for Creating the Creating the Screw Jack
Assembly and Drafting
Part Modeling – General Steps
For most of the parts (body, cover, handle, etc.), the procedure remained almost the same.
I created a new part file, selected a suitable datum plane, drew the required sketch (with
centerline when needed), and then used extrude or revolve features to generate the 3D
model. After that, I added features such as holes, cuts, fillets, and chamfers wherever
necessary. Each part was saved with a proper name.
Part Modeling – Body (Using Revolve Feature)
1. I created a new part file in Creo and named it Body.
2. I selected the Front Plane as the sketching plane.
3. Before starting the profile, I first drew a vertical centerline, which acted as the axis of
revolution.
4. On one side of the centerline, I sketched the cross-sectional profile of the body. The
profile was made closed and fully constrained with the required dimensions such as
height, outer and inner diameters, and thickness.
5. I applied the Revolve feature by revolving the profile 360° about the centerline, which
generated the complete cylindrical body.
6. I added further features such as holes, cuts, and filletschamfers wherever required.
7. Finally, I saved the model as Body.prt.
Part Modeling – Screw and Nut (Using Helical Sweep for Square
Thread)
1. I created a new part file for the screw (and similarly for the nut).
2. I selected the appropriate sketch plane and drew the base profile of the screw/nut.
3. I defined a helical trajectory by specifying the pitch, height, and axis of the helix.
4. I sketched the square thread profile on a perpendicular plane to the helix.
5. Using the Helical Sweep tool, I swept the square profile along the helix to generate the
threads.
6. For the nut, I created the internal square thread using the same method but applied
it as a cut inside the cylindrical profile.
7. Finally, I added finishing features like chamfers and saved the models as Screw.prt
and Nut.prt.
Assembly
1. I created a new assembly file and inserted the body as the first component, fixing its
position.
2. I sequentially inserted the screw, nut, cover, and handle into the assembly.
3. I applied suitable constraints such as mate, align, and insert to assemble the parts
correctly.
4. I verified the motion of the screw inside the nut and the movement of the handle.
5. Finally, I saved the assembly as ScrewJack.asm.
Drafting of Drawing
1. I created a new drawing file and selected the required part or assembly as the model.
2. I placed the standard orthographic views (front, top, and side) along with an isometric
view.
3. I added dimensions, centerlines, and section views wherever necessary.
4. I ensured proper title block, scale, and projection method were used.
5. Finally, I saved the drawing and exported it as PDF for submission.