Experiment No. 3 Machine tool alignment testing on machine tool – Lathe / Drilling / Milling.

 

EXPERIMENT NO 3

 

TITLE: Machine Tool Alignment Test On any two machines like- Lathe, Drilling, Milling.

TITLE: Machine Tool Alignment Test On any two machines like- Lathe, Drilling, Milling.

APPARATUS: 

A lathe in good working condition with all standard accessories,
i.e. live and dead centers, sleeve etc, Dial indicator, Dial stand 'with magnetic base, Flexible dial stand, Parallel blocks, Straight edge, Straight bar, Standard teit mandrel, Straight spirit level, Box type spirit level, Alignment microscope, Taut wire, Set of spanners, Mandrel and centre draw bar.

THEORY: 

For metrology purposes the term alignment refers to two axes merged in each other or where one axis extends beyond the other.
Two lines or axes are said to be in alignment when their distance apart at several points over a given length is measured and this distance does not exceed a given standard tolerance.
The dimensions of a gauge, its surface finish, geometry and accurate production of components/parts depend upon the inherent quality and accuracy of the machine tool used for its manufacture.
1.    The alignment of various machine parts in relation to one other. This is very important because th e geometry of various shapes is based an the relative motions between various machine parts and hence on alignment of various parts,
the quality and accuracy of the control devices and driving mechanism.
2.    The various tests applied to any machine tool could be grouped as below :
(a)    Tests for the level of installation of machine in horizontal and vertical planes, (b) Tests for flatness of machine bed and for straightness and parallelism of bed ways or bearing surfaces,
(c)    Tests for perpendicularity of guide ways to other guide ways or bearing surfaces,
(d)    Tests for true running of the main spindle and its axial movements,
(e)    Tests for parallelism of spindle axis to guldeways or bearing surfaces.
(f)    Tests for the line of movement of various members, e.g., saddle and table cross slides etc. along their ways,
(g)    Practical tests in which some test pieces are machined and their accuracy and finish is checked.

Please see the video for alignment test for lathe machine tailstock 

PROCEDURE:

1.    Clean all surfaces perfectly on which alignment tests are to be performed,
2.    Level the bed of lathe for longitudinal as well as cross directions,
3.    Follow the test chart for performing different alignment tests.

ALIGNMENT TABLE

S. NO	OBJECT	MEASURING INSTRUMENT	PERMISSIBLE ERROR	ACTUAL ERROR
1.	A bed verification of leveling of slide ways: a. Longitudinal verification and straightening of slide ways in vertical plane	Precision levels optical or other method. Precision level	500<=0<=1000 0.02 local tolerance. 0.075 for any length of 250>0>1000 For each 1000 increase in distance between centers beyond 1000 add to the corresponding	0.01-0010
2.	Checking parallelism of tailstock movement to carriage movement: a.        In vertical plane b.        In horizontal plane	Dial gauge	DC<=1500 a and b 0.03, local tolerance 0.02 for any length of 500 OC>1500 a     and     b     0.04     local tolerance 0.03 for any length	0.015
3.	Checking of parallelism of axis outside of tailstock sleeve to carriage movement: a.        In vertical b.        In horizontal	Dial gauge	a.     0.02/100 upward b.   0.015/100 frontward	0.01   0.015
4.	Checking parallelism of taper base of sleeve to carry movement on length equal to Oa/2 to maximum of 300	Dial gauge and mandrel	0.03/300 upward 0.03/300 forward	0.01 0.01-00
5.	C-Carriage checking of straightening                carriage movement in horizontal direction	Dial gauge and mandrel between centre or straight edge	500<=OC<1000 0.02DC>1000 To reach or increase in OC beyond 1000
6.	D-centre         checking         of difference in height between headstock and tailstock	Dial gauge and test mandrel	0.01      tailstock      centre higher     than     headstock centre
7.	E-Headstock spindle a.     measurement of periodic axial slip b.     Measurement of carrying of face plate resting on the surface	Dial gauge F=force=0	a.     0.01 b.   0.02 Including periodic axial slip	0.005
8.	Measurement of run out of spindle nose centering sleeve or centre	Dial gauge indicator F=force=0	0.01	0.01
9.	Measurement of run out of axis of centre a.        at the spindle nose of housing b.        at a distance from spindle nose equal to Da/2 or not more than 300	Dial gauge or test mandrel	a.     0.01 b.   0.02 c.     For        measuring length of 300	0.005 0.01

 CONCLUSION: Hence we have studied the alignment test for lathe.