something that I want to share..

Have you ever join a test? especially a last semester test.. I'm doing it now, but it still bad.. I got a good result last semester, in all of subject.. but know..I think I've failed, because I only answer few of them, I don't know what I have to do..It is too late to repair everything, I know these are my mistakes, I never studied before, I just played and did something useless.
Now I just write down everything what I want to say, I don't need any comment about everything in the past, I just want to know how to motivate my self..do you know? I always motivate my friend around me, but it's only motivate them, not me..although I told them everything than can make spirits for them, but I can't do it to my self..
My girl friend said that teher is no useless thing in this world, and I know it.. Now, I just try to do my best, although I'm not sure and I don't have any confidence..

Bahan Ujian Akhir Semester 2 Material Teknik

1. Tujuan pengujian mekanik adalah untuk mengetahui atau menentukan sifat material
2. Jenis - jenis pengujian mekanik

• Pengujian Statik (uji tarik, tekan, uji kekerasan dan uji tekuk)
• Pengujian Dinamik (uji lelah)
• Pengujian Impak/kejut (charpy, ized, drop weight, ballistic)

3. tujuan uji tarik : mengetahui sifat material jika diberi beban tarik
prinsip pengujian tarik : benda kerja ditarik hingga putus
4. data yang diperoleh dari pengujian tarik adalah besarnya perubahan panjang benda dan besarnya gaya yang digunakan
5. Sifat mekanik yang yang bisa diperoleh dari hasil pengujian tarik adalah yield strength, kekuatan tarik maksimum, modulus elastisitas, keuletan
6. teknik pengujian kekerasan :

• Brinell : alat yang digunakan adalah bola dari baja, penghitungan kekuatan berdasarkan diameter lubang yang terbentuk dari penekanan bola baja terhadap benda kerja
• Vickers : pengujian menggunakan intan yang berbentuk piramid, penghitungan kekuatannya berdasarkan besarnya diagonal pada lubang hasil penekanan
• Rockwell : pengujiannya menggunakan diamond cone, perhitungannya dengan menghitungn selisih kedalaman awal dengan kedalaman setelah penekanan

Press Tool (Cutting Process)

cutting process is consist of two parts :
1. penetration process
2. fracture process

all of that process is determined by clearance
and clearance consist of 3 parts :
1. proper clearance (normal)
2. excessive clearance (hard)

• big clearance
• big burr
• make big radius in cutting part
• small penetration
• make radius in scrap
  

3. insufficient clearance

machinary process

some subject that we learn in machining process are :
1. eccentric shaft
2. dividing head
3. boring head
4. comminution of tools
5. making gear process


1. Eccentric Shaft
eccentric shaft is a workpiece that have co-axial more than 1
fungtion of eccentric shaft is to change angular motions to be rectilinear motion

some tools that we use to lock substance in making eccentric shaft :

• between center : by making a new co-axial
• independent chuck with 4 jowl
• dependent chuck with three jowl
• face plate : for a thin worksheet
• klem and face plate combination

in making eccentric shaft, wa have to care about :

• rotary speed (rpm)
• touch tip of chisel to highest division of workpiece
• don't use chisel with carbide to avoids pounding
• add ballast to make it balance if the eccentricity is big

2nd

yah...
I'm here again..I just write everything that I want to write..
too many things happened today..
for example
I went to my college only for cleaning and prepare the room for observed tomorrow, then I unloaded a part of a machine, just it..no more than it.
I wasn't make any sketch that I have to make, maybe I can do it tomorrow.
But there is something that made me happy..
I met my girlfriend after several days we don't meet each other, do you know how I feel?And there was something bad too..
my friend in 3rd class had forced by a weapon and he got hurts, how poor he is..
And my classmates got an accident this afternoon..
he had trouble with my other friend's bike..
he beat a car and than he had to repair it.
I want to help him, but I don't know haw I can do it
then I called my lecturer to get permit all off my friend to help this guy..
beside everything have happened, I wasn't try to leanr everything and prepare my self to meet the last semester examination, I know that I have to get good result, but I'm still lazy to study..
I told you that I have many dream that I have to get, but I never try to make first stpep to walk on it..
please remember me that I have to catch all of my dream..
c u tomorrow..

1st

this is the first time I write something since I made this blog..
I just writing and tell every one that I need this activity
this blog is made to help me learn everything, to help my study, and my business
I wanto to make a business but I don't really know what I have to do to begin..
an I always scare to start it even someone told me there is nothing can be scared..
She always tell me that I have to be brave and do the best that I can do, she is the only one that know everything about me..
ok..back to the to the topic..hehehe..
I'll try my best and get everything that I wanna get, becouse I have too many dream and I belive I can catch it..

this is only something that I want to write for 1st time in this blog..
next time I'll write more about my study...especially about some subject that I hate
I don't really hate but they're hard to learn..becouse I have to remember everything that my lecturer said..