Cutting 2" Thick Aluminum Plate

[Jose Rivera]

Here is where a good size band-saw comes as the best tool.
I read the advise using a table saw. I the aluminum is the gummy type you'll have fun !!
May I add is you go for a table-saw ... make sure that your butt-chicks are tight also !!!!

[Rolland]

Why not clamp it to the mill table and use an end mill to cut a groove as far through as possible and then lock your saw in the vertical position and hand feed it to cut the rest. I made a table for my saw out of 6 X 10 X 1/4 inch plate and screw it to the saw using the two screws that hold the blade guide. I use it to cut anything from 16 guage to 3/4 inch al.

[lakeside53]

Worm drive.... Done it many times...

[Orrin]

I've cut aluminum thicker than that on my horizontal mill. I made an arbor for a carbide-tipped wood saw blade and used it as if it were a slitting saw.

I've also used table saws and Skil-type saws; but, I like using the mill best of all. It is a more controlled cut and not nearly as noisy as the other methods.

Orrin

[seal killer]

Orrin--

So far, you win the prize for scaring me the LEAST. That's important at this time of year.

Anything special about that blade other than carbide tipped?

--Bill

[mechanicalmagic]

Bill,
Since you are one of the few with a H/V milling machine, I vote for Orrin's method.
HF sells a carbide saw blade.
http://www.harborfreight.com/7-1-4-c5-c ... blade.html

I have one I on my Miter Saw for thin AL. But that's a high speed motor. I'd run the mill at top speed, and wear all the safety stuff mentioned. A frequent lube shot would also be in order.

Dave J.

[seal killer]

Dave--

This is sounding more and more like a doable deal. The kids are grown, left home and married, my wife will be in Detroit for a few days, I can move the soon-to-be-vintage Crossfire out along with my bling-bling Sportster. Oh, I better take Dillon Press' Ms. October out, too.

The fastest speed on my mill is 2950 RPM. Would you just crank it up as high as it would go?

--Bill

[seal killer]

All--

The component I want to make is a high rise adapter that will allow me to put the guide scope in the same plane as the focuser and DSLR. All of these things are relatively heavy. Placing them in the same plane should make balancing the device far easier.

Basically, I want to turn part of that 2" aluminum plate into an I-frame component. The top and bottom of the frame will be 0.5" thick. The central portion connecting the top and bottom portions will be 0.375" thick. There will be round holes drilled in the central portion to reduce weight. Additonally, there will be a threaded bolt hole located two in the top plate and two in the bottom plate. Metal will be removed from the central plate to allow access to these bolt holes. The metal removed will be rectangular in shape.

Here is a highly imprecise drawing. You'll get the ideas. I'm open to your ideas; I solicit them. Basically, I need a light-weight I-beam 13.5" long and 1.75" wide and 7.5" tall. I arbitrarily set the top and bottom plates at 0.5" thick and the central plate--the riser--at 0.375" thick. The load bolted to the top plate will be small telescope and guide camera weighing a total of 6.65lbs. The main optical telescope will be attached to the bottom plate.

Apparently, either no one has thought of this as the solution to a common telescope balance problem or they don't want to admit it. I have thought of it and if it doesn't work I will admit it, too!

I appreciate your comments concerning the idea, the design, the implementation, and whether you think I will really turn my mill into a big, weird table saw with 5 axis of movement and a power feed. I tell you what, it sounds like just the thing with Halloween coming along.

--Bill

[randyc]

OK, the problem may be resolved, LOL, but I've been typing for a while so I'll include the following, if nobody minds.

I've used some of the suggested techniques - plus the "sawzall", or even a "saber saw" with fine-pitch blades - NOT very time-effective. I also use the radial arm saw routinely for cutting sheet-metal - NOT heavy bar stock using a Porter-Cable variable pitch carbide blade.

The table saw scares me the most because work can't be clamped securely as can be the case on a sturdy old DeWalt radial saw, but I have done it and often. My technique was to cut LESS than halfway through the workpiece then reverse and repeat the cut. Of course, the same workpiece edge must be guided along the fence.

Problem is that there is no accessability for lubricating the blade (candle wax is my preference) which means small DOC and fast feeds … judge the safety for yourself ... CAREFULLY. This method is similar to the one that Harold described and also requires a carbide-tipped saw blade. The table saw technique scares me the most !

I made a "radial router" that resides on the same long table as the radial arm saw and that has also been successful in cutting sheet metal (carbide cutters, of course). The work can be clamped down to the table and the router guided along its captive rails across the sheet metal - we're talking ONLY about aluminum, of course and candle wax is still my desirable lube !

The method that feels most comfortable is one very much like Orrin described except in the vertical mill (I'd love to have a horizontal but it's been evading me for four or five decades). This is a very NOISY operation - noisier than the other ones - because one edge is typically unsupported. Here's a photo of the saw blade + arbor, unassembled:

I used a dado - fine teeth interrupted by fairly large notches - for various reasons (carries lubricant and clears chips well but mostly readily available, LOL). Made an arbor for the saw blade with a 3/4 CRS shank to suit the largest R-8 collet for my vertical mill. Then brazed a three inch diameter, 3/8 thick mild steel disc to the shank and stress-relieved the assembly in the kitchen oven.

The assembly was then finished by facing the disc true to the shank and turning the lower four inches of the arbor to .249 diameter. (My thinking at the time was that the .249 arbor would be useful if a supporting guide was required - for example a .250 drill bushing). I've not used the arbor with a guide so far. Here's a photo of the blade + arbor:

As can be seen, the saw blade was modified by drilling two holes in the hub to affix it to the arbor. I used a 1/4 carbide masonry drill to drill the saw blades (I modified several at the same time) feeding very c-a-r-e-f-u-l-l-y to avoid chipping the drill !!

I don't have photos of the sawing operation but the concept is visualized easily enough: workpiece held vertically in the milling vise and the saw passed through it as the "X" axis of the mill is slowly traversed while liberally lubricating the HSS blade - spindle RPM adjusted to my slowest speed of 120 RPM. I would have preferred carbide-tipped blades and a higher spindle RPM but I chose the HSS dado blades because I thought they might be useful for various width slotting operations and - frankly - I wasn't yet confident that carbide-tipped circular saw blades intended for woodworking wood be suitable.

FWIW, I've not used any of the modified blades for slotting operations to date. Most of my work is small and end mills are adequate because I'm not pressed for time. If the shrieking noise is unbearable, it can be slightly dampened by adding a heavy C-clamp to the top (unsupported) of the workpiece. Remember to support the work and apply upward pressure as the saw exits the cut !

Cheers,
Randy C

[seal killer]

Randy--

That's a very interesting technique and story. Thanks for taking the time to write it. I learned quite a bit.

--Bill

[Dave_C]

Seal Killer,

When I ran put of options I did this:

I took a long length end mill (2 flute), hooked up my big shop vac to keep chips out of the cut and just ran the mill back and forth till I got it cut off. If you keep the chips out of the cut you can go deep.

I have a power drive on the X axis so it leaves both hands free to hold the vac tube.
Dave C.

[seal killer]

Dave--

I have a power drive on the x axis and one of those big 16 gallon Craftsman super-suckers. However, I only have one end mill that will easily hit two inches. It IS a double-end, deadly sharp, Putnam, though.

Unless my metal vendor wants something outrageously high-dollar to cut the wp, he's going to get the job. I've learned a lot reading how everyone would go about it. I will put all of it to use one day . . . but hopefully not soon on that big chunk of aluminum!

--Bill