[delraydella]

If you've read any of the later posts in "Aluminum Finishing", I said i would post the story and pictures of a project i'm working on. So here it is! I'm trying to get into the business of making custom hardware for signs, displays, exhibits, etc and figured i would start with pieces called "Standoffs" (pictured below) They pretty much do what they say they do. They hold a sign or graphic panel a certain distance from the wall or other mounting piece.They are made out of a variety of materials, aluminum, stainless steel, carbon steel , and finished in a variety of finishes and colours.

I didn't make these ones in the pictures, they are from a Google image search, but it gives a general idea of what I'm trying to make.

[delraydella]

I'm starting out with 6061 aluminum for this project because it's easy to machine and is easily available. When things get going and i get the kinks out of the process, I'll start making them out of stainless and other materials. Throughout the process, I'll go through the machinery used and any special tools or jigs i might have made or used.

The first step is buying the rod. I buy 12foot lengths of 1 inch and 1 1/4 inch rod and cut them down in a chop saw to 8 and 3/4" inches long. After they are cut down, each piece goes in the lathe and is centre drilled on one end with a #2 center drill. The first picture is of my lathe, a 1943 Monarch EE Precision Toolmakers engine lathe. If you've ever heard the expression "such and such is the Cadilac of whatever",well, the Monarch is the Rolls Royce of lathes!

After center drilling, each piece is turned down .005". This evens up outer radius of the rod and cleans up the outside of the pieces. For turning i use a carbide insert with the biggest cutting radius available for that insert. Together with a fast turning speed and the slowest feed speed, it gives a nice finished look. The wider the radius on the insert, the smoother the cut it will give, combined with speed and feed rate.

Each tool and gage that i use for any step is specific to that step, so every step in the process has it's own cutter, it's own carriage stop, etc. It save a lot of time not readjusting things and it keeps every piece exactly the same dimension.

[Otto Nobedder]

Ah,

So this is what you were up to when trying to resolve lathe-chuck marks in aluminum. I see why the sequence was an issue; At some point, finished material has to go in the jaws.

And I'm very jealous of that lathe!

Steve S

[delraydella]

It's a beautiful piece of machinery, isn't it? Would you believe I paid less than $800 for it? I bought it government surplus from NASA! I've had to put about a $1000 into it for parts and tooling, etc, but even with that it still worth more than 10 times any comparably priced piece of Chinese junk.

Some of the parts are a little worn, but after 70 years, whose aren't? Usually the lead and crossfeed screws will have some backlash in them on older engine lathes but if make allowances for that, they work just fine and will hold tolerances extremely well.

[delraydella]

Ater the pieces are turned, they go back to the chopsaw to get cut down to their approximate finished sizes. The caps, or the top parts of the standoff are usually 3/8ths to a half inch thick depending on who makes them, but for now, all of my cap pieces will be a finished thickness of a half inch. Further down the road I'll add different thicknesses to the offering if there's a demand for that. The barrels, or the longer lower part of the standoff also come in various lengths, but right now I'm only concentrating on 3 sizes...1, 2 and 3 inch long barrels. Again, I'll add different lengths as they are wanted or needed.

For the rough size cutting of the pieces, I'll add a 1/16th of an inch to all the pieces so a piece that will be finished sized to 3 inches will be cut to 3 and a 16th. Once they are all cut, each piece goes back in the lathe and gets faced and center drilled. The facing cleans up all the ugly saw marks, squares the ends and takes them down to their finished length. One end of each cap and both ends of each barrel is center drilled with a #3 centerdrill.

Each piece is now ready to be drilled for tapping.

The first picture show a cap piece being faced. You'll note the copper sleeves on the chuck jaws (Thanks Steve S.!!) They help keep the chuck jaws from marring the pieces.

The second picture is some depth and carriage stops I made. The steel ones fit on a dovetail mounted on the carriage and prevent the carriage from advancing any further once it reaches the desired size. These are made out of 2 pieces of mild steel that are capscrewed together, the lower part has a dovetail cut into it to match the carriage dovetail. The top part is drilled and tapped for a 3/8-24 thread. The finer thread gives a better fine adjustment than a coarse thread would. The adjustment bolts are shopmade, too. The threaded part is allthread and the head is a piece of 3/4 inch drill rod that i knurled, drilled through and welded onto the allthread. The wood piece on the bottom fits into the chuck and keeps the pieces at a standard stickout in the chuck. There are different thickness chuck stops for every different length of barrel. You can see the chuckstop behind the cap piece in the top picture. The chuckstops are made out of red oak and some fender washers, bolted together and the face is covered with green sticky back felt.

The third picture is one of the carriage stops doing its job.

[TamJeff]

That's really nice. Gotta love the old iron, too.

[delraydella]

For sure, that old stuff was built to last. I have 4 machines from WW2 era, one from a defense plant, 2 came from the Navy, I don't where the 4th was from originally. Nothing short of a power blackout stops them and if I keep them oiled and greased and take care of them, they'll be running long after I'm gone and working in that great big shop up in the sky ( or down below, I'm not sure yet!)

I've looked at buying brand new machinery and from what I've seen it's either a cheap piece of crap that won't last 6 months or they want an arm and a leg for it and you need 5 different degrees in engineering to run the thing. There's not much available between the two extremes that i've found so far. That's why i like the old stuff that sold as surplus. For a fraction of the cost of new, a little elbow grease, maybe some new parts, you can have some nice equipment.

[TamJeff]

The 800.00 price seems like a steal. I had to look twice. I admit not being savvy to auctions and such but I would have bought that in a heartbeat for that, even if it needed a complete rebuild. You have to be proud of that machine. Before I went to welding school, I tried to find a machinist school first. I live in Florida and there was nothing of the sort here that I recall. Seems I would have had to go up North to PA or somewhere like that I think was the closest to me at the time.

Don't own a lathe but did rebuild an older 60's vintage, 3hp 12" unisaw at one point that I got from a cabinet shop going out of business for $350. It had been scavenged of a few parts like the knob for the fence lock and the tilt mechanism needed some work. Everyone else was after the newer saw they were selling and ignoring the old one. Repainted it, cleaned it all up and cut the mahogany frames for my boat and someone offered me $1200 for it so I took the money like a dummy, thinking I could just go out and find another. The motor alone had to weigh 80#. Loved the sound of that thing starting up.

[delraydella]

I would love to find a deal like that on an old Unisaw, especially if it was a 3 phase! We have one from the 90's, it works very well but it only has a 220 motor so it tends to stall out at times over an extended period of heavy usage. It has a sheet metal base, the cast iron ones are long gone, but it still weighs in at about 600 pounds or more. I think we paid about $2500 for it (?????) in 1997, so the guy you sold yours to got a great deal.

[delraydella]

The next (and almost last) step in the process is drilling and tapping the pieces. For drilling into the aluminum, I use a "Fast Spiral" drill bit. A fast spiral bit is made for drilling into softer materials. One of the biggest problems with drilling fairly deep holes in any material is geting the chips out of the drill flutes. A fast spiral bit is ground and fluted differently, so it uses a little less torque to cut the hole and the spiral flutes help push the chips out at a better rate. You can use a slower speed at a faster feed rate with them and not worry about clogging. They are a little bit more expensive than regular drill bits, but they save a lot of time and aggravation. The first picture below shows the 2 bits side by side. The fast spiral is on the bottom.

Tapping is another area where getting rid of the chips is extremely important. If the piece to be tapped is drilled clean through, there is an escape hole for the chips to go, but I'm tapping blind holes (Not drilled through) so the chances of breaking a tap by clogging it are much greater. If you've ever broken a tap in anything, you know it is next to impossible to remove it. The piece is ruined. Don't waste your money on broken tap removal tools either..... they don't work. The tangs will most likely break off long before the tap will budge.

I could hand tap everyhing, turning the tap a few turns, backing it off to clear the chips..............but I'm lazy. So I bought a machine tapper!(Pictured below)With this device you can set the speed and torque for any size hole and material. It also has automatic reversing feature when it hits bottom, so you get a nice clean threaded hole every time. But even with this machine i still have the problem of chip clearance. A regular spiral tap will not work here, because they are meant to backed in and out to clear the chips. So for this job I'm using Spiral Fluted bottoming and pointed taps. Much like the fast spiral fluted drill bits, these taps are made to clear out the chips as they push in. I also use a cutting oil for this part called "Tap Magic for Aluminum" it keeps everything flowing nicely. Kerosene will also work well as a lubricant for tapping aluminum if you don't want to spend the money on name brand stuff.

The last picture is a table full of the pieces just out of the lathe, ready to be tapped. The next step will be getting them anodized, but I'll send them out for that.

[TamJeff]

Great thread. No pun intended. I use tap magic as well but absolutely hate the smell of it. I have a can here with kerosene and just a bit of automatic transmission fluid in it that I use that seems to work well.

I am a stickler over drill bits. I recently just restocked with Norseman bits. I have not used them enough to have an opinion of them just yet. I had a bunch of older TRW jobber packs from before. Those were pretty decent.

I also have one of those early 20th century Bridgeport tap and die sets in a wood case that contains both standard and machine thread profiles up to 1". It's the type where you have to assemble each half of the dies with set screws that hold them in place on the head, along with a specific centering collar. They are still very sharp.

[delraydella]

Yes, you're absolutely correct.....Tap Magic for aluminum does smell really bad! I've been blowing out the tapped holes with compressed air and that atomizes the stuff and the smell gets everywhere. I think i'm going to try to make a dip tank with some laquer thinner in it and just dissolve the stuff away instead of blowing it all over the place.

I used to use a water based cutting fluid that had cinnamon in it to get rid of the smell. It was great stuff but I haven't seen it in a while.

[Otto Nobedder]

I've had good results tapping with light mineral oil, and it's dirt cheap. No smell at all.

You can usually find it in the HBA section of any big grocery, or Wal-Mart, with the laxatives.

Steve S

[TamJeff]

For hole saws, I like using a spray bottle with dawn dish detergent in water. That way I can cool the hole cutter while continuously washing the chips and slurry out of the groove.

I am a big fan of broaches or annular cutters on aluminum if all you have is a drill press or hand drill.

Since you have added discussion about drill bits and you seem to be more involved with precision machine type work, what is the best countersink these days for hand work? I recently bought a weldon countersink but haven't had it long enough to check it's durability. Used to have those older uni-bit stepped countersinks but I don't trust them now that Irwin has taken it over. I typically use a 5/8ths.

[delraydella]

i will almost always use a combined drill/ countersink like the one pictured below (also called a centerdrill). They come in both 60 and 82 degree cs angles and they are probably even made to British standard angles. I don't know who makes the ones I buy, but I'll check when i go back in on Monday. I also don't know if they even make a 5/8ths. The largest i've ever seen is a #5 and thats only a 7/16ths shank. The only other countersinks i have, i inherited from a guy who was a machinist back in the 1950's and 60's.

Weldon is a good name. They should last quite awhile.

[delraydella]

TamJeff,

here is a link to the company that makes the centerdrill/countersink combo I use....

http://www.centerdrills.com/


I'm not sure from who or where you would buy them from, I inherited mine,but it looks like you would have to buy them direct from the manufacturer. i will attest to the fact that they are very well made and should last for a very long time. Mine have outlived their original owner by 20 years and are still going strong.

Other Steve

[TamJeff]

Thank you. I will look into that. I can probably get them online.

[delraydella]

Here's a picture of a standoff set that is just back from the annodizing shop. I think overall that they came out pretty good! There are still a few things i have to do before i can start to sell them.....the barrels ( the larger part) will need a slight chamfer on both edges and i can tell from the cap that I'm not quite centered on the facing cut, but neither of those two is that big of a deal.


Other Steve

[taperwing]

The Monarch lathe is a very good lathe. What you need for your work is a 5C collet holder and closer. This lathe is perfect for this. With a 5C collet you don't have to worry about chuck jaw marks and you can buy 5C collet stops. There are less expensive screw type closer or lever closers. The lever type are supper fast to use and a lot less hard on your hands. I used the lever type 5C collet closer for years on Monarch lathes. Also you need a carbide insert cut off tool and holder. With the 5C collet you will be able to make cuts right up to the holder with out risk of hitting the chuck or getting your fingers or hand smashed in the chuck.

[delraydella]

Thanks taperwing!

That's a great idea. I was trying to figure out a way to incorporate some sort of collet that would close around the pieces by the pressure of the jaws closing,but i never could come up with anything. Your idea should work very well...

Welcome to the forum, by the way.

Other Steve

[nevinlee]

Can you please share the details on how to go for aluminium finishing? Thanks in advance.
__________________
machining ceramics

[ritzblitz]

Can you please share the details on how to go for aluminium finishing? Thanks in advance.

What type of finish are you looking for?

High spindle speed and a slow feed rate should grant you a decent finish. If it is not what you want, using scotch brite on the part works well, just move slowly and you will get a nice finish.

To the OP- nice lathe man.

[delraydella]

The radius on the cutting edge of the bit will also give different finishes. The widest radius available for the type of cutter insert you're using, higher turning speed and slowest feed rate will give the smoothest finish. Going down progressively to smaller radiis will leave progressively higher amounts of cut lines. Cutter bit selection is important too, there are cutters designed for specific types of materials and alloys.

[delraydella]

As i go through all of the processes i get ideas on how to improve things and also add different features to the pieces. Looking at what the competition is doing is also a great way to improve anything. Every now and then there is a call for a tamper proof assembly and i imagined that would be a great feature to add on an optional basis (and to sell for more $$$).

Tamperproof in this instance mostly means theft proof. Since the caps are just screwed on, whats to stop someone from just unscrewing it and taking the graphic panels or whatever else the standoffs are supporting? The caps need a way to lock on to their bolt, but still need to be able to come apart whenever their is a changout of the panels. So now I made a way to drill into the side of the cap, thread it and put in an allen screw that when tightened will lock into the bolt threads.

The first picture is the drilling fixure. It's a v-block and a piece of 3/4" drill rod that is center drilled and tapped for a 1/4-20 piece of threaded rod that the cap screws onto for drill placement. I milled off the top of the rod so the threads wouldn't get damaged when the drill bit pokes through. The second picture shows a #29 drill for an 8-32 thread. The third is the cap with an allen screw installed.