CNC router: suitable for FRC?

[DavisDad]

Originally Posted by DonRotolo

I don't understand the question.

I'm interested in a non CNC method for making these lightening cut-outs (1/4" Al):
'



By drilling 1/2" holes and cutting between with something like this:



Your thoughts appreciated.

[DonRotolo]

Ah. OK.

Um, no. I don't think you can control a chop saw carefully enough to do it.

Traditional method would be to drill holes, and then use a jigsaw or scroll saw to cut out the openings.

Less common method would be to use a wood router, hand-held, with a 1/4" or larger aluminum-cutting bit, using a plywood or MDF template, and a bearing or collar, to cut out the 'triangles' after drilling access holes. Note that this is more dangerous than average, gotta be super careful and slow (about 1" per second). And hearing/eye/skin protection is mandatory. (We did this with 3/16" aluminum some years ago, nobody died...)

Of course, you can also do it with a coping saw. Assign it to a freshman.

[Akash Rastogi]

Originally Posted by DonRotolo

Traditional method would be to drill holes, and then use a jigsaw or scroll saw to cut out the openings.

Print your CAD drawing scaled 1:1, tape it to wood, cut out wood part using bandsaw + scroll saw, proceed to use wood template on metal part + scroll saw. You can just tape the paper to your metal, but I like having the wooden part as well.

[DavisDad]

Originally Posted by DonRotolo

Ah. OK.

Um, no. I don't think you can control a chop saw carefully enough to do it...

What if the piece were clamped fast in a jig that controlled the depth of the plunge cut; there would be a stop to control cut length/depth?

[techhelpbb]

Originally Posted by DavisDad

What if the piece were clamped fast in a jig that controlled the depth of the plunge cut; there would be a stop to control cut length/depth?

The blade is round. Unless you can plunge to the diameter of the blade you'll get a pocket with an arc ramp at either end you'll have to cut anyway. The other suggestions like a scroll saw are just as good and I bet you will end up there anyway. No sense in adding risk by increasing the surface area between the blade and work and that circular saw is likely to screach.

[DavisDad]

thanks y'all for the feedback.

I've been cutting Al plate, bar, and rod w/ a 10" carpentry chop saw with excellent results. The carbide tip blade cuts fine through 4" rectangular bar. Some cuts start as plunge cut and I've had no problems.

My thinking is that it'd be quicker and cleaner to make the cut below and use a jig saw to remove "ramp". I need 8 each of these and could set jig for each angle/depth and get it done faster than scrolling each cut-out.