This document describes the design and fabrication of a nut tapping attachment for a drilling machine. The attachment aims to automate the tapping process for cutting internal threads in holes. It uses a bent shank tap connected to a spindle powered by the drilling machine. Nuts will be fed into the attachment automatically using a pneumatic cylinder and sliding path. After each nut is tapped, it will move along the bent shank tap and collect in a container. The attachment is designed to reduce the time and labor costs of manual tapping while improving accuracy and productivity. It is estimated to cost 16,500 INR to fabricate. Key advantages include eliminating separate tapping operations, reducing power needs, and enabling higher production rates with less floor space and maintenance requirements

1. Project Title:- Design and fabrication of a nut tapping
attachment for drilling machine
Guided by : Dr D J Tidke
Presented by:Abhishek Gawande A-04
Palash Thuturkar A-50
Niraj Pimplapure A-48
Ajinkya Naydu A-74

2. CONTENTS
 Introduction
 Design & assembly
 Working procedure
 Need for the attachment
 Cost estimation
 Advantages & applications
 References

3. INTRODUCTION
 Tapping is the operation of cutting
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
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internal threads in a hole using a cutting
tool called Tap.
Most of the industries uses the
conventional method -- hand tapping.
Threads are taped by manually rotating &
feeding the taps through the drilled hole
This conventional method is very time
consuming process, less accurate and
includes higher labour cost, and
ultimately less productivity.
So there is a scope to develop the machine
for tapping operation.

4.  An attachment eliminates the purchasing of a new
unit which serves the same purpose.
 By implementing an attachment to a unit, the capacity
of the unit can be increased which is very economical.
 Thus based on the functional and economical
aspects we are fabricating a unique attatchment.

5.  Bent shank tap is used for
tapping
 The size of the bent shank
is M-12
 The drilling machine
motor will provide power
to the attachment.
 The main advantage for
using bent shank tap is
that the bent part will
provide the indirect drive
to the spindle.

6. Project Design
Design of sliding path and pneumatic cylinder

7.  Nuts will slide through
hopper.
 Locking arrangement is
use so that only single
nut will enter the path
during tapping.
 After tapping of 1st nut
the cylinder will go back
and next nut will enter
into the path.

8. Spindle Design
Design of Spindle

9. Sectional View of Spindle

10.  Spindle will be fabricated
in two parts
 Material used for
fabricating the spindle is
mild steel
 Bent shank tap will fit
inside the spindle

11. Bent Shank Tap
 Bent shank tap is used
for tapping
 Size of tap is M-12
 Due to bent portion of
shank the nut will move
upward and finally it
gets collected in the
container after tapping
process.

12. Working Procedure
 The taper tap is
connected with a bent
rod which is made to
rotate at high speed
along with the spindle
causing rotation of the
tap at the same speed.
 The blanks are
automatically pushed
intermittently under the
tap and after threading
the tap returns but along
with the threaded nut.

13.  Finally the accumulated nuts are
thrown out form the rod by
centrifugal force to come out from
the hopper.
 the bent shank tap held in a
casing which has nuts along the
shank and fit the cavity. The
casing is provided the drive by
drilling machine spindle. Nut
feeding and spindle operating
mechanisms are also designed.

14.  Also we have designed
the path for the feeding
of the nut.
 Nut will be pushed
forward using
pneumatics.
 After tapping, the nut
will move along the
shank and at the end, it
will get collected in the
container.

15. NEED FOR ATTACHMENT
• 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.

16.  For example, a lathe 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.

17. COST ESTIMATION
Items
Estimated Cost
Bent Shank Tap (2 pieces)
4900
Piston cylinder arrangement
1500
Compressor
2000
Hexagonal blanks
100
Material cost
1000
Fabrication works
5000
Motor ,gears ,switches & casing
2000
TOTAL ESTIMATED COST
16500

18. Advantages
No need for doing tapping separately.
 The extra power required to do the tapping is
reduced.
Time is reduced.
Minimum number of components, so the
maintenance of the assembly is easier.
No skilled operators are required.
Enables high production rate.
The attachment is less expensive.
Consumes less floor area.
Noiseless and smooth in operation.
The attachment is auto reversible

19. REFERENCES
 nptel.iitm.ac.in/
 en.wikipedia.org/
 www.youtube.com/?gl=IN
 www.howstuffworks.com/

20. Thank You