Bench Work Practice

When i am accepted as a student on Swiss Project on Politechnic for Mechanic ITB, in first year we are trained how to use manual tool such as handsaw, chisel and file. We have to make some shape as drawing to make sure the dimension tolerance is not run out. Whatever the shape is we don't allow to use machine tool. For example my name is Patrisisus Iwan, so i have to make first letter of my name that is 'P' letter. From unshape raw material must be shaped like P with tight dimension tolerance. For some student is a boring practice. You imagine that from 7 am till 2 pm frommonday to thursday in one year. On friday and saturday we study theoritical matter. Actually that practice build your sense of benchwork and machine tool. Because we are dealing with very tight tolerance you can say 50micron till 10micron so we must have enough skill for that job.

One case my customer Ishikawa corp want their mold to be modified. Their customerwant a 0,4mm round shape in their part. I make a electrode from copper.I cut it using lathe machine then i am finishing with file to shape it about 0,4mm. Because i think maybe is just for aesthetic matter,i just use manual tool. A file.The electrode i make then put it in EDM (Electro Discharge Machine) as cutting tool to cut the mold.

Using High Technology such as CNC EDM we just simply choose the parameter we want speed, surface finish and dimension tolerance etc.

With this machine you do not have to finishing like polishing this machine can achieve 0,1micron surface finish.

After finish i send the mold already modified for trial in plastic injection machine.

That surprise me is they cut the injection part in four section then they check it with Visual Projector. The result is good with plus minus 0,05mm. Wow... close enough.

Thanks to the 1 year practice.