Nibbler? Or Dremel Router? Cutting Alu Instrument Panel

[Dockhead]

Originally Posted by skipmac

In case you haven't encountered this, look carefully at the blades before you buy. I bought a new pack for my sabre saw and couldn't control it during the cut. Saw wanted to bounce out of the hole every stroke. Finally looked closely at the blade and the teeth were angled to cut on the down-stroke instead of the up-stroke so was pushing the saw up out of the hole.

I had never noticed the blades come with the teeth either way. Just assumed they all cut the same.

Am I the only one that didn't know this?

That was exactly my problem. Eureka! I bet that was what was going on.

[Dockhead]

Originally Posted by a64pilot

Really, give a cut off wheel in your dremel a try first, this one, the big one that is fiberglass reinforced, you will be surprised how easy it is, draw the outline you want cut, cut it a tiny bit small, finish with a file. We do "skins" for aircraft every day here at the plant that way, .040 aluminum, and pretty big sheets, but use a die grinder and bigger wheel.

https://www.dremel.com/en-us/Accesso...spx?pid=456-01

That was the first thing I tried -- didn't work for me -- but I'll try it again for sure.

[a64pilot]

Just practice on some scrap, if you go the saw route, blade speed is your friend, run the blade fast, use just a little pressure to feed it, too slow or too much pressure and the blade grabs

[Siberianhusky]

I would use a hole saw and a hand hacksaw, sabre saw, cutoff disc...whatever works to get the corners, drilling the corners is a good idea.
Some work with a file then silicon carbide wet dry paper to finish things up.
Would definatly clamp it down to a block of wood on the drill press.
3mm aluminum is so easy to cut I would just use a hacksaw to cut out the corners, might not be possible due to the shape/size.
I'd also cover it with a couple layers of masking tape on the good side, no point in starting out with it scratched.
If you use a cutoff disc on an angle grider be carefull, discs can load up and catch really easily in aluminum.

[hellosailor]

Four circular holes at the corners, even if you are going to square them off later with a file. Then connect the dots with a cut-off wheel, reinforced Dremel wheel, or handsaw, whichever suits you. But if you use a saw, even with the correct metal blades, also remember to lubricate the blade! Helps to keep it cooler as well as making the cutting smoother. Even a couple of drops of 3-in-1 oil, cutting oil is not mandatory.(G)


You might also want to start with a slightly smaller cut-out than what you need, and use a bastard file or similar to even up & smooth out the edges to final size.

[jimbunyard]

If you're dismounting the existing equipment and have just a flat piece of 3 mm aluminum, hole saw to match the corner radiuses from the front, circular saw with a carbide tipped blade from the back to connect the corner holes. Finish straight cuts with a hacksaw blade wrapped on one end with duct tape if need be. No oil is needed for aluminum unless you just want to make a mess. If you're unaccustomed to plunge cutting with a circular saw, practice on a piece of plywood first. Clamp the instrument panel to a piece of plywood and the plywood to sawhorses or a bench. A small drill press is really useful for getting the radiused corners in the right place. Finish up with the appropriate round and flat files.

If you must use a sabre saw, use the slowest and finest cutting speed possible, and in this case oil might help some.

Be careful using cutoff wheels unless they're specifically for aluminum. They can load up, bind, and shatter otherwise.

If you get bimetallic hole saws they will last through many, many holes in aluminum. If you use oil they will work in steel, cast iron and stainless also. The attached picture shows plugs and holes cut in and from aluminum, steel and stainless in thicknesses varying from 1/8" to 1/2"...

[UNCIVILIZED]

Originally Posted by Siberianhusky

I would use a hole saw and a hand hacksaw, sabre saw, cutoff disc...whatever works to get the corners, drilling the corners is a good idea.
Some work with a file then silicon carbide wet dry paper to finish things up.
Would definatly clamp it down to a block of wood on the drill press.
3mm aluminum is so easy to cut I would just use a hacksaw to cut out the corners, might not be possible due to the shape/size.
I'd also cover it with a couple layers of masking tape on the good side, no point in starting out with it scratched.
If you use a cutoff disc on an angle grider be carefull, discs can load up and catch really easily in aluminum.

Ah, a voice of reason & common sense. And, to add to it:

Firstly, for all intents & purposes, you want the part you're working on, to be Bolted Down: To something Heavy (as in nigh on immovable). Ditto on any guide rails that you employ if you're going to use power tools.

And given your issues with power tools, & the questions that you're asking about them. Stick to hand tools.
It's a LOT harder for things to get out of control (& expensive) when you use them vs. power tools.

Might I suggest a hacksaw, except for drilling the corner holes in a square or rectangular cutout. Assuming that the hole is to be square or rectangular that is.

Also, if it's a circular hole, there's naught which says that you can't first start off with your hole saw in a hand powered drill... using a bit of cutting oil along with it. In order to get your initial grooves for the hole saw, well cut into the metal's surface. If not using it to go all of the way through. I mean it's only aluminum.

That, or use a battery powered drill on a Very low speed, for the Entire cut. Stopping Much more frequently than you think that you need to. So as to prevent the possibility of inadvertently speeding things up, & thus getting out of control.

Plus, you want a SHARP hole saw (8 out of 10 are dull, & 9.9 out of 10 are 1/2 way through a job). Preferably use a Carbide one if you can find such. They're worth the price & effort in locating.

Also, cut your hole a bit undersized, & then finish size it with files & sandpaper. Regardless of whether you're using hand tools, or power.
And with most any machining or cutting job; templates, jigs, & guide rails are pretty much your best friend. Ditto on practicing on other things first, before working on the real deal.
And this applies to working in; wood, metal, plastic, composites, etc.

Power tools (ever more increasingly powerful ones) are all the rage the last few decades. Especially for the home handyman (foolishly, IMO).
But many years ago (& even now in some circles), one of the tests given to young (apprentice) machinists, was to file a piece of metal into a perfect cube.
And if one cared to make the test "tough" (as if it weren't already), they'd specify dimensions for the cube.

So there's naught wrong with using hand tools, & becoming Very proficient with them. Heck, guys build whole boats & houses with'em. Some who's names you're familiar with.

[Reefmagnet]

What in the blazes type of aluminium are you guys cutting that causes a 10000+ rpm cutting disc to bind up in 3mm thick sheet?

[barnakiel]

A Dremel is too light. I have been there.

b.

[captain58sailin]

For smaller rectangular holes, I used a dremel with the cutting wheel, went through a few, but hey they are cheap. Ditto on the using tape to protect the plate whilst cutting the holes, I also used the dremel to jewel the plate after I was done cutting so any mars were hardly noticeable.

[Sandero]

As noted...

Properly clamp the work. ALL work must be properly clamped. Mark out your size rectangle (you can do this on masking tape too... drill the 4 corners.

You can use a metal cutting blade in reciprocal saw at the correct speed with lube to cut close to the line INSIDE of it. finish up with a metal file. You can also use a hack saw to cut the 4 sides.

You can alternatively tale a piece of work with a rectangle cut in it to use a guide with a router. Use carbide bits. You can take small depth cuts. Use a smallish bit. Routers use collet guides or there are "follow bits".

You can also drill a hole and use the router to cut full depth following the wood form. Use a variable speed router set for the correct cutting speed for alum.

clean up corners with file.

[S/V Alchemy]

Originally Posted by Dockhead

Thanks for all the great comments.

The whole is rectangular. So I guess I'm going to give it another go with the sabre saw. Finest blade I can find, and clamp the bejeezus out of it.

We shall see!

Hole saw for holes, and drill holess at the corners of rectangles and use a coping saw to do it by hand. Yes, slow, but yes, more control. If you want a blended approach, cut a "slot" from the drilled hole along the desired straight line, and then go to the sabre saw or jigsaw (I prefer the latter) with the right blade, and finish with the coping saw to the next hole.

Smooth edges with a Dremel or a grinder if you have the room.

Aluminum plate is fussy, but not that difficult to work with using wood-grade tools.

[pcmm]

3mm alu is pretty easy to work with using regular wood working tools! If you can just slow them down a bit, a jig saw should have no problem cutting 3mm Alu, just use a fine blade. Slow down the saw a bit and clamp your work down like you would for any other material! Heck I built a new mast step out of 10mm ALU using nothing more than an old poer miter saw box and my table saw! just cut a bit more slowly. I even cut overlapping lap joints using my mitre box. I did have to have someone else weld it up though as I dont have that skill set.

[Aaarrgh]

Vibrating "plunge saw" - very easy to control for precise straight cuts. Drill corners for rounded corners.

[oleman]

Neither! Table saw or drill press and file.
Always clamp all stock so there is absolutely no stock movement if attempting a hole saw in metal. Use lots of coolant, a JOY (dish soap) solution works and there is no cleanup mess.