Which tool for this job?

Machine Shop
1

I have a part that I need to make several (numerous) copies of

I will design the part in Fusion360 or solidworks, and I can cam it up for the cuts etc.

The material will be aluminum 3/16" thick 3" x 9"

Attached is a really general picture of what the part looks like in inkscape. The dotted lines are where the part would be “bent” using a compact bender at roughly 60 degrees.

But my question is this.

What is the ideal (human labor a factor) method for

a) cutting the center holes
b) drilling the other holes (all 3mm)
c) cutting the rectangle with rounded corners
d) chamfering sharp edges

I had thought about using a 3" by 4 foot 3/16 inch aluminum flat bar and cutting the rectangles on the chop saw then doing the rest on the emco, pcb mill, or shapeoko

or, a sheet of aluminum on the cnc router (using the smallest possible endmill to reduce waste), but I don’t know if the CNC router has a 3mm bit for the screw holes… can you fit a regular drill bit on the cnc router?

I would like to make 60 of them to start with.

thoughts?

2

What machine are you planning to machine this part?

The HAAS would need you to do the design in something other then Inkscape. Unless you have access to a CAM package beyond what we have at the space, I think you will need to use something other then inkscape.

You also need to think about how you will clamp this piece down for machining. 3/16" is quite thin and you appear to need to machine all sides of the part.

BTW, Aluminum is NOT allowed in the CNC router

1 Like
3

Yeah I meant to edit that out, of course it would be in something the machines could use. Whatever the tool requires.

4

If using a 3 x 4 foot piece of aluminum, I would cut out the rough stock with a jig (sabre) saw.

I would also create a fixture plate that I could clamp the thin metal down from two sides. Mill the edges of the other two sides in one setup, then switch the clamps to the freshly milled sides and mill the remaining two sides edges and the holes.

5

Yeah thats along the lines that I was just thinking when you said no al. on the cnc router

but this search result turns up lots of instances of “aluminum on the cnc router”

but I agree it is probably not great idea because of the dust collector sucking up shards.

https://talk.dallasmakerspace.org/search?q=cnc%20router%20aluminum

6

My understanding is that the board was considering legal action against a former member who recently milled aluminum on the cnc router after being told that was not allowed.

7

Exactly how many is “a lot”? The Bridgeport and the Haas are the logical choices. Is the volume large enough to justify programing the Haas. Also the radii on the corners will be difficult on the Bridgeport without a specialty cutter.
I would start by drilling 1 hole, then using a simple jig to quickly locate and drill a second hole. One can then use the two holes to clamp say 5 pieces together and macine them as one unit about 1 inch thick. Or if you are like the grimm tailor, maybe do seven at one blow! Doing the radii on the Hass , the number stacked together will be limited by the length of the mill’s cutting flutes.

2 Likes