How would you go about doing...

[nessimibrahim]

Hello,newb here i have a pm 25 bench mill and I'm trying to do a cut out on a aluminum box Would like to know whats the best way to do this? Also i have a easson DRO and have attached the a photo of the work piece.

 

[Chipper5783]

How large is the work piece? What size are the holes? How thick is the material? What do you have for tooling (vise, hold downs, end mills, drill bits, boring head)? How critical is the hole size, location and surface finish (i.e. tolerance requirements)?

 

[nessimibrahim]

4.4 x 2.3 x 1.1 inches, the hole is to be rectangular .9 x .56 inchs, thickness is about .15 inchs and is die cast aluminum Tooling i have vise, hold downs,wide asortment of endmills ranging in size and same for drill bits and no boring head yet.s. Tolerances ar't really over critical.

 

[JimDawson]

For the round holes a step drill would be my tool of choice. Your vise should hold it ok.

For rectangular cut out, drill a starter hole for the end mill, then cut it out. I would use a 1/8 inch 2 flute. Maybe the make the first pass a bit small then finish on size. Then clean up the corners with a file.

 

[nessimibrahim]

Thanks for the taking the time to help a guy out. I've been watching the beginners video on youtube by the lazymachinst and reading as well. Just need to start some sort of basic project to get me started.

 

[rock_breaker]

I would drill the holes first including the counter sink. Next I would bolt it in a T-slot and index it to cut the shallow rectangular hole with a small mill and probably a knife or chisel for the corners. If it were on spacers above the table it may be possible to trim the sides and ends using the indexed set-up. Trimming the sides may require clamping to the table or holding in a vise on parallels. Not really sure if I interpret the problem right but this cat has been skinned two ways now.

 

[JimDawson]

I would run the 1/8 end mill at about 2000 RPM, use some WD-40 as a cutting fluid. Cast aluminum is pretty forgiving to machine. You should be able to make a full depth cut if you're careful.

Breaking an end mill is not the end of the world, they are expendable.

 

[nessimibrahim]

I owe you guys thanks alot.

 

[Asm109]

I would come back and ask, "Are dead sharp corners in the rectangle absolutely essential?"
You can create clearance so a square cornered part fits properly in the rectangle if that is what it is there for. Just drill small holes slightly beyond the corner points.

 

[4ssss]

I would start by packing the box with something solid so as not to crush it.