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Cutting Aluminum on Router Table

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16K views 27 replies 15 participants last post by  difalkner  
#1 ·
Hi,
I suppose cutting aluminum is best on the sable saw, but is there a way of making cuts on the router table? That question is for my information for another day. Right now I’m interested in just trimming 1/4” aluminum sheet to size. I bought aluminum sheet from Midwest Aluminum and Steel and the tolerance quoted is -0” to +1/8”. The company does a little better than that. Some dimensions are right on. Other dimensions are 1/32” proud, one is 3/64” proud, and some are 1/16” proud. I don’t wand any surprises so I’d like to know how the router table will cut. First I have new and sharp straight bits to work with. I was thinking to setup the fence like a jointer by fixing second fence and put a rule along that fence but extending a few inches over the first fence. Then I’d stick a feeler gauge between the rule and the first fence to offset the fence by the amount I want to cut off. Then I’d tighten it. I have a screw adjustment for the fence assembly and I can move the complete fence in to expose the bit the amount I want to cut off. I had the idea of taking my multimeter set to resistance measurement and clip one end to the rule and the other to the router bit. Then I can set the rule along the second fence and over the bit. Then using the fine adjustment of the fence assembly, slide them back exposing the bit gradually until I see zero ohms. Then the bit is right in line with the second fence. I realize I must rotate the bit so that a cutting edge faces out. Also, by first and second fences, I mean going right to left. I have a question. If I set this up to cut say 1/16” exactly, will it cut 1/16” exactly or do I have to compensate for something? I was thinking of running the table at full speed for this. I have a nice 3.25hp PC motor in my table and the table is the top-of-the-line Woodpecker. It seems well made to me. I am soliciting advice. Can somebody help me. Thank you in advance. Sincerely, Chris Redding.
 
#2 ·
welcome N/A..
bit speed and rake of the cutter would be an issue...
the TS is your safest best bet w/ the right blade... (-5°TCG 60/T)
 
#3 ·
1/4” is thicker than anything I’ve tried . I don’t know the gauge, but I router checker plate aluminum with no issues. Well other than prematurely wearing the bit out .

If I had to router 1/4” , I’d cut it with a jig saw first as close to the line as I could get , and clamp a guide and use a router to finish .
It would be messy, but I’ve heard of guys having someone spray wd40 as they’re cutting
 

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#4 ·
Aluminum is a bit tricky. The first thing to know is what alloy. Some cut quite well while other are terrible. 2000 and 6000 series can be easily milled, 3000 and 5000 series not so much and will need a fair amount of clean up. I've mostly done 6000 (6061), with good results. Cutting 3000 series even with a super shallow DOC was an exercise in frustration - a very poor quality cut. The router seemed to push the metal around more than cut it. I was trying to mill a 40 mil sheet for bending into a complex shape.

Given that you are trying to shave a tiny bit off it might go ok but I would be tempted to try grinding. Mark your edge and grind to that. If you do use the router, slow it down to the slowest speed you have. Definitely use a lubricant - wd40 is fine but even mineral oil is usable in a pinch.
 
#5 ·
Welcome to the forum, Chris! Add your first name to your profile to clear the N/a in the side panel. Add your location, as well.

Photos always help in getting good advice and we do like photos so show us your shop, tools, projects, etc. whenever you're ready.

David

PS - a carriage return or two will make your posts easier to read
 
#7 ·
I used a panel blade in my table saw mounted backwards . But as I mentioned I was cutting thinner material.
A table saws not going to work to well if things are out of square though, so a Panel blade in a track saw or skill saw may be a good alternative
 
#8 · (Edited by Moderator)
Hi,
This is what I’ve learned so far. The aluminum is 6061, which is desirable. WD40 is good. Slow speed and feed. I should check bit after each cut and replace or sharpen bad bits. Carbide is desirable. I looked at the following page:

//daycounter.com/Calculators/GCode/Feed-Rate-Calculator.

You need to put “https:” in front.

I think I need to use the lowest speed on my router table (10,000rpm) with a mini bit, 1/8” and the feed is a maximum of 34 in/min provided I have 2 flutes and 17 in/min if one flute. I have a 1/8” into 1/4” adapter. I think it important to do the math regarding feed. For example, one cut is 35”. That will take one or two minutes depending on the flutes. I can use the chronograph on my watch to check my progress and maybe take a sharpie and divide the edge into 6 or 12 parts and keep up with the feed and for each 10 second interval, I’ll cut to another sharpie mark. Finally, I think I’ll try a downward feather board and focus on inward force against the fence and move right to left at a slow and uniform rate. And pray. Chris.
 
#10 ·
In the shops I have seen aluminum cut on a router table. but like was pointed out the softer the aluminum the harder to cut. All of the glaziers who install the aluminum for the store fronts and window walls on the highrise buildings use Johnson stick wax on the chop saws for lube. In the shops on the routers they use an oil emulsion of some sort of oil and water to cool the routerbit. Their machines are built for that with recycling oil bath sumps, I wouldn't use that at home on a woodworking router table. Cutting Aluminum is so messy I would not do it in my shop, unless on the tablesaw to keep the mess contained as much as possible.
Herb
 
#11 ·
Hi,
I apologise for my little rant at the end of my last post. I was having a little technical problem and got a little pissed. Anyway I'd like to say that I don't have a tablesaw yet. I was thinking that if I bought one thing, it should be the most versatile piece of equipment and that would be freehand routers and a router table. I have recently purchased a radial drill press and a scroll saw. Band saw, table saw, jointer, planer, and lathe are on a to buy list. Chris.
 
#12 ·
The hoops you are going through are meant to protect you and our other members from spammers and hackers. The forum got hacked a few years ago although I'm not sure how valuable the info was that they got but our parent company Verticalscope https://www.verticalscope.com/ which is based here in Toronto, Canada decided that they should protect themselves and us by requiring a more aggressive password protocol. Probably mostly for their protection than ours. The 10 post criteria for adding links has been here since the forum began and it's to protect the forum from spammers. It doesn't work totally as we get some that post something like "nice job" 10 times and then post their ads. But it does give us Mods a little more time to catch them and get rid of them. I eliminated one just seconds before I answered this thread. Apparently you told moderator David Falkner that your free speech was being violated by these rules and you were thinking of suing. If you want to pursue that then take it up with Verticalscope and their legal department but you might find that more difficult than you first imagined as they are in Canada and you are in the U.S. Plus we had rules you agreed to before you posted.
 
#13 ·
When I worked at Keyport Torpedo Station, the metal shop (which should have been called the aluminum shop) had Unisaw dedicated to cutting sheets of aluminum. Accordingly, I have used mine to do the same. Most of that has been 3/8" cut down to 3/4" wide for jigs for the bandsaws, table saw, or sander.

Initially, I used my 60 tooth ten inch carbides and they did a nice job. I tried to stay with blades that had minimal set (just seemed like a good idea). For no specific reason, other than to lessen the wear on my good blades, I bought a 7-1/4" blade purposed for cutting aluminum.

Needless to say, cutting aluminum is noisy. Too, it throws hot aluminum at you. Obviously, not wearing eye protection will proved to you why it needed to be worn.

I have a handheld toy called a Twin Cutter. It has two blades side by side and a fraction of an inch apart. One blade turns in one direction and the other in the opposite direction. It eats metal and aluminum like a minter through bass wood.

The Twin Cutter came with round sticks I have, long since, learned are paraffin wax, like the stuff used for canning. Without them, the cutter would be destroyed in minutes, as the aluminum built up between the blades. The same problem doesn't exist when cutting iron.

Using this knowledge, I started drawing a wax line where the blade would cut. After doing so, I IMMEDIATELY noticed the cuts were quieter, and the metal kicked off the cuts didn't sting as much.

Clearly, carbide blades work well cutting aluminum. The design of the teeth plays a big roll in the ease of use and the safety. I would never run a carbide blade backwards in metal anymore than I would in wood. It seems a good way to knock teeth off (I was around a mill and saw what happens when a blade launches teeth -if the fellow hadn't been holding a block of cedar it would have been like got hit by the equivalent of a 22 cal automatic).

SIDE NOTE: My metal cut off saw has carbide teeth too and it does grate cutting thick aluminum, but I do not the aluminum loads a little, so wax would be useful there too.

If you do tackle aluminum on a router, wax the daylights out of it. That would help. A table saw would help more. If you don't have one, there is no reason a circular saw with a fine blade wouldn't get the job done.
 
#14 · (Edited)
#16 ·
I have one of these blades https://www.amazon.com/Diablo-D0756N-Cutting-Saw-Blade/dp/B00008WQ37/ref=sr_1_1?crid=1N637VVL395RU&keywords=diablo+7+1%2F4+in.+x+56-teeth+laminate%2Fnon-ferrous+metal+cutting+blade&qid=1576528563&sprefix=7-1%2F4%22+non+ferrous+metal+cutting+blade%2Caps%2C162&sr=8-1 mounted in one of the old Craftsman Radial Miter Saws and it does a great job of cutting aluminum strips and extrusions. Best to use a relatively slow speed, and sure makes a mess, but it seems to do a much better job than a run-of-the-mill carbide blade.

The attached photo shows the saw (and blade) being used to cut some aluminum extrusion. It's one that I use a lot, so I made a specific sub-table for it, complete with a "tunnel" to enclose the extrusion and a toggle clamp to hole the extrusion safely while I was cutting. I have several similar tables, some for cutting extrusions and another, again with a hold-down, to hold aluminum sheet while I'm cutting it.
 

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#17 ·
When using my 10" blades, I used the 60 tooth. It cut pretty smooth, which was good, since I was cutting bars for guides and, of course, wanted them to fit close with minimal sanding.

I believe less set on the teeth made for a smoother cut too.

Here is a web site for the Frued 7-1/4 inch blade. I didn't figure I needed a ten (more expensive), since I was cutting stuff around 3/8" top 1/2". It talks about optimum blade geometry and triple grind....


https://www.diablotools.com/products/D0756N
 
#23 ·
Yes, metal working is not only dirtier, more difficult/cumbersome and also more dangerous.

Pure cotton is certainly the way to go; hence many old school (car) guys wear t shirts and jeans........I have a pile of work clothes that looks like I got shot gunned from all the thru burns from welding and grinding on my car.

Leather welding apron gloves and boots are the minimum along with a full face helmet for doing either.

Years ago I had to grind the base frame for a Recaro seat I had bought and wanted to fit into my Mustang.
Only way to get at it without full disassembly was to hold everything a certain way so the grinder and wheel would fit into the spot. Took about 20 minutes of solid sparking to clearance everything. Most of the way through, I decided to remove one welding glove for better feel and grip. The final couple of minutes ended up with the sparks/grinding material being fired directly at my thumb.

Result: The next day I ended up at a walk in clinic because my thumb had swollen to twice it's normal size, and was so tender that looking at it felt like it was being cauterized by a blow torch. Had to soak it in salt water for 7 days until the swelling went down and the metal bits started being pushed back out of the now softened skin. Basically similar to blood poisoning and a REALLY uncomfortable and painful experience. No long term issues thankfully, but that one was 100% my own stupidity. Needless to say, learned my lesson about metal working without gloves.

Aluminum is particularly nasty because you can't pull it out with a magnet. It also has lower melting temp than steel and is also stronger by mass. The dust is also highly poisonous. I am planning on maybe trying my phenolic Woodpecker table with alum plate at some point, but the various thoughts such as scratching/damaging it needlessly, melting anything the chips come into contact with as well as the potential fire starter is making me think again. I will also be working on a carbon fiber dash panel, which may end up on the router table - that is another dangerous dust and fragments that require care. I bought a properly sized Milwaukee 2-5/8" holesaw for the instruments to fit, so only the big speedometer and Monster Tachometer will need to be cut some other way.

No wonder woodworking is more fun, lol.
 
#25 ·
Years ago I had to grind the base frame for a Recaro seat I had bought and wanted to fit into my Mustang.
No wonder woodworking is more fun, lol.
In 1969 I had a '65 Mustang and I was doing my best as a high school student to install the Ford Le Mans package into my 289 small block. Part of that involved porting and polishing the heads but I also went with screw-in studs, mechanical lifters, larger intake valves, and CC'd the combustion chambers after polishing them best I could with my Dremel.

It was a big undertaking for a high school student with low budget and few tools but I got it done. The only thing is I couldn't see well enough in our little storage building because the only safety glasses I had were tinted. So I took them off to do the grinding and polishing. And you guessed it - cast iron specks in my eyes. This happened on a Thursday and I left the next morning with a youth group from church for a 3-day retreat, coming back Sunday evening.

By Saturday morning I could no longer wear my contacts and I'm legally blind without them so I had to be helped around camp for two days. By Sunday morning my eyes were swollen, everything around my eyes was red and tearing constantly, and I was miserable to say the least.

We got home in time for me to see the moon landing on July 20, 1969. I recall sitting about two feet from the TV and opening my eyes at the very moment of 'That's one small step...'

The next morning my Mom took me to the eye doctor where he did minor surgery on one eye and used a magnet on the other to get several pieces out of my eyes. I have never done anything close to that since time without eye protection!

Btw, my '65 Mustang ran like a scalded dog when I finished with it. Balanced, blueprinted, stripped the weight down to 2,650 lbs., etc. and ran 0-100 mph in 10 seconds flat. Of all the things I've gotten rid of through the years, the one possession I with I still had is that '65 Mustang. :grin:

David
 
#24 ·
The proper prescribed blade for non-ferrous cutting is a “triple-chip” and it has very little to zero rake and is not unlike a rip blade, except that every 3rd tooth is a raker tooth with the corners chamfered off.

I have a 10” one for use in my RAS, and it works very well, but hold downs/feather boards are essential because the big saws can get a bit grabby with the stock if it is not guided straight and true.

For routers, which are essentially the same as a CNC spindle that is routinely used for working aluminum, the right bit choice is an “end mill.” These have 4 flutes and are routinely used for this very purpose in mills. Lubricant is wise if you care about your $30 bits, stock, and personal safety; I’ve heard that AstroGlide is THE choice lube (least messy)(really? 😂😂), but WD40 works, as well as rubbing alcohol (needs verification), and special concentrates for batching water-oil emulsions. I would seriously consider making a dedicated, thin melamine top for this.
 
#26 ·
I route T6061, Mic6 and Alca 5 ranging in thickness from 1/4" to 3/4" on a regular basis. A jig saw or bandsaw are the safest saws to rough cut stock to size. A table saw or miter saw besides throwing hot chips all over the place are terrors when something goes wrong. Al is very gummy and a lubricant helps prevent the chips from being welded to the cutter. I've used Boelube, WD-40, and FORMAX saw blade wax stick. I can't say I have a favorite other than I don't like Boelube in stick form.

Because Al is gummy, you want a bit w/lots of chip clearance. That means a 1 or 2 flutes. The O style 1 flute is very effective. The bit should be a solid carbide so that limits you to 1/4" or 1/2" diameters. The solid carbide is more rigid than a brazed tip construction and is harder because the carbide isn't brazed.

The part is always mounted on a sled which is guided by a fence on the router table. The sled has good handholds out of harms way. Never feed Al stock by hand - a lot can go wrong in an instant. Never climb feed. Use a dial indicator to set the depth of cut from 0.003" to 0.015". Start with 0.002"to confirm the high and low sections of the edge and then work your way to deep cuts.
 
#28 ·
Awesome build, Paul! And a very clean engine and compartment. I never had the budget for anything but street tires but I managed to run high 12's, still not bad for a high-school kid just reading books and mowing yards.

My daughter found some old photos and brought them over not long ago and this Polaroid of my ported and polished head, not quite finished, was in the batch -


David