i‘m going to enter the malaysian young inventor competitionbut the problem is that my invention needs me to attach a piece of copper sheet to a stainless steel knifehow may i do so
I'd go with rivets. If you can, find a punch instead of using a drill. If you can't find a punch, make sure you buy a drill bit intended for stainless steel too. Otherwise you will ruin your drill and possibly hurt yourself.
Three methods come to mind: 1) silver soldering or brazing 2) drill and attach with rivets or machine screws 3) adhesives such as epoxy or double-side tape The method you choose will depend on the use of the assembly. Adhesives will interfere with electrical contact, but is the easiest method and perhaps the only method for thin sheets of copper. Soldering or brazing will provide a permanent bond if you have the equipment and select the flux and the solder or braze carefully. It requires the most skill. A welding shop would be able to do the job for you. Stainless steel is not easy to drill, but a local machine shop should be able to help. Machine screws (small bolts) and nuts would be easiest. Rivets could provide a permanent bond and better appearance if installed correctly. Machine screws in tapped holes are probably not worth the effort, as tapping stainless steel is relatively difficult.
I should be possible to solder it, you will need to mechanically clean the stainless (like with fine sandpaper) to remove the transparent oxide layer, and use an aggressive flux (rosin core solder for electronics is unlikely to work) If you can find a solder/flux combination made for stainless that would be ideal, but plumbers solder and an ordinary acid flux might work if the cleaning is adequate. Silver soldering with a suitable flux might also work, but the heat might be bad for the cutting edge of the knife.
the gear ratio would be drastically different decreasing the power quite a bit i dont know how much you have looked into this, but most jeep off roaders opt to swap their jeep motors,, 4cyl.str8 6or even the 8 to a gm 350 if that helps you with your question
