View Full Version : New Here - questions on getting started with an elbow

02-22-2005, 04:53 PM
Hi new here. I've only bent metal a few times, mostly while taking a shop class many years ago in highschool. I'm helping my brother out with his AC business and I only need to make one product for him the elbow from the unit to the roof. Eventually I would like to do more but this is the only item he continually uses.

Please don't beat me up too bad since I 'm no expert but trying to learn more. Here are the questions: (by the way if I need to get a book or if some one could point me in the correct direction, please let me know.

Ok, first of all I can do the math to calculate the radius and can compute the distances from the unit to the roof. I understand how to make the side of the elbow, plus allowing a little extra (1"??) to allow it to be all joined together. From what I have been reading I need to get a Pittsburgh machine to attach the sides (Cheeks) to the heel and the throat. Is that correct? So if I leave 1" extra on the cheek along the heel, what do I use to bend the 1" tab, does it need to be bent, do you use a box and pan brake, or is this handled with the Puitsburgh machine. (I guess the same guestion would be asked in the throat area)

Also how would a splitter/divider be made to attach to the inside of the elbow? I'm assuming I would actually make three cheeks and tack weld/spot weld the inner vane to the inside of the heel and the throat.

So because I'm starting off what machines would you recommend to buy if this is the only piece I'll be making? Here is my list: (I think the material is 22 or 24 guage I'll be bending)

Pittsburgh machine
Box and pan break (or do I only need to get a flat brake)
Do I need a rotary machine?

(I'm not looking at high dollar machines, like maybe 2200 for the pittsburgh machine, around 1400 to 1800 for the brake.) I figure in roughly two months time I should be able to make the money back in the elbows I would make for him.)

Of course I'll need tools for clipping out the metal, and probably a spot welder if I need to attach the interior vane.

Any help would be greatly appreciated. Thanks.

02-22-2005, 06:08 PM
Click on "The Library" link on the upper left and spend some time there. All of your elbow questions will be answered.

Screws or rivets work good for that splitter vane or vane rail material. No welder needed.

If you only want to buy one brake, I would get a box and pan, unless funds do not allow. Watch the capacities, and remember that closing a hem on a piece of 22 ga will tax a brake rated at 22 ga., especially at full length. The smaller the flange you are bending (say, a 1/4 inch flange), the more difficult it is for the brake to do it, especially as the length of the metal is longer.

At a minimum, you will need an Easy Edger to form the male part of the pittsburgh seam, unless you get the power attachment for the machine.

02-22-2005, 07:29 PM
the flange on the cheeks will be 1/4". the allowance on the heel and throat will be 1" each side. you also have an S and Drive allowance or what ever connection your using. unless you want to make your female pitts in the brake, buy a pittsburg. or a brake and an easy edge.


02-23-2005, 06:55 PM
THanks for the tips guys but the one nagging question I have is, and I can't find a difinative answer is, on the cheek pieces, the 1/4" and the 1" do you need to bend these 90 some how prior to using a pittsburgh or an easy edge, or does the pittsburgh and easy edge do that for you.

I guess what I'm trying to figure out is how do you make those 90 bends prior to seeming (say the cheek and the heel) the two pieces together? I'm assuming that the pittsburg or the easy edge will seem the two pieces together and then make then 90 with each other?

I've never used a pittsburgh or an easy edge before, mainly just a pan and box break to make some simple stuff, if I had to put a lid on it I would just screw through the heel and the flange. Never built anything that had a radius with a 90 edge (kind of reminds me of a can)

02-24-2005, 04:08 AM
You always form the pittsburgh as a falt pattern, then do your bending? I'll do the light cross brakes on the fitting before the piece gets fed through the pittsburgh machine. If the fitting is radius type, you do not need to cross brake the heel or throat. The easy flanger or the power flanger attachment is what makes the 1/4 in. bend on the cheek. Remember, when laying it out add the neccessay allowance for this.

Good Luck

02-24-2005, 10:40 AM
Hey Bud, thanks for the info. That was exactly what I was wondering.

So what would be a better machine if just making the return/supply elbow the pittsburgh or the easy edger? I think the pittsburgh was around $2200 plus maybe another $700 for the flanger. The Easy Edger I think I have seen them between $400 and $700.

My gut instinct is telling me to get the easy edger because it is cheaper and at this time I'm only making this one piece. Is there any large advantage in getting a pittsburgh over the easy edger in making this one piece? What about material thickness, is one better than the other? From what I can tell one of the they both seem to make a small assortment of locking bends but the pittsburgh can be expanded with other attachments and the pittsburgh is a floor unit verse the easy edge being a work bench mount.

Thanks for all the help guys.

One other thing, is a rotary machine the same as an edger but electric?

02-24-2005, 05:35 PM
First of all, stop thinking about the expensive equipment if you're only going to make one piece? Go to your nearest sheet metal contractor? If you're only making one a month, go to your nearest sheet metal contractor?

There are four machines neccessary, the pittsburgh machine, brake and some sort of flanger, hand or attachment. You'll also need a slip roll to form the heel and cheek. A big investment for only one fitting.

The rotery machine is not the same as the easy edger (easy edger is a brand name) if your skill was there, a burring machine would do the same thing, the only difference is that the easy edger has an attached plate to hold the material properly?

02-24-2005, 06:17 PM
Actually I'm only making I should say one part just Elbows and probably like 24 of them per month. I'm not planning on making any other duct work except this piece that goes between the AC unit and the roof.

So I was thinking that if all I needed was and edger to connect the heel and the throat to the cheek and then maybe a standard brake to bent the flange end then why bother spend extra money on a machine I will not need.

OK bear with me here this last time, here is what I've pieced together:

I need a brake to bend flanges on both ends of the heel and the throat as well as both ends of the cheeks (the ends that will meet up to the ac unit and the ends that meet the roof.

Slip roller to arch the heel and the throat.

I need some sort of flanger, be it one that hooks to the pittsburgh or one that mounts to the table and is hand powered to attach the heel and the throat to the cheeks.

Then I'm done. I'm assuming if I get the hand powered edger then I would not have to get the pittsburgh unless you tell me that I need the pittsburgh to make the locks between the throat and cheek and the heel and cheek.

I've never used a pittsburgh or an edger so I don't know if they do two seperat things or if the edger actually creates a lock for radius pieces or if it just bends the heel and the cheek together.

Sorry for all the newbie questions but I just don't know who else to ask. If there is a good book or web site that shows you what each of these machine could do I think that would help. My only other option is finding a local machine supplier and seeing if they can give me some sort of demonstration but I figured you guys would know more about this subject since you work with this stuff.

Is the rotary machine like a pittsburgh but smaller? From what I have been seeing on the web, a rotary machine looks like it makes locks (maybe not as many) like a pittsburgh.

02-24-2005, 06:17 PM
sorry this was a double post - can figure out how to delete

02-24-2005, 06:51 PM
You still need the pittsburg machine...the flanger is for the cheeks or the 1/4 inch 90 degree bend, sorry but for 900.00 thats all it does:) the pittsburgh is for the heel and throat the actuall lock, The flange or 1/4 inch 90 deg. bend is inserted into the lock that was formed by the pittsburgh. The roller is to roll the radius in the heel and if used the throat and the break is for the cross brake or if you happen to make the throat straight instead of radius?

I'll see if I can get some pictures up here for you...

02-25-2005, 10:03 AM
Thanks Bud. I was just having difficulty in picturing how the heel and cheek went together and then how to make the 1/4" 90 bend. I think I understand now.

02-25-2005, 06:40 PM
You could make the pittsburg seam in the brake. A guy can get fairly fast after a while. I did this quite a bit when I first started in business. I did buy a pittsburger when business picked up. Fabbing a pitts in a brake certainly is not as fast as a machine.

03-20-2009, 06:47 PM
You said you had to make 24 per month. You may want to get a sheetmetal shop to build them for you. The more we make of a product the cheaper they get. As far as the Pittsburg Lock, nobody thought of a Pocket lock and a few tex screws. That would be faster than making a Pittsburg in the break. i love these old posts. :roll:

03-25-2009, 11:03 PM
Maybe a large shop would let you use their equipment,for a price or just make to order. Faster and cheaper than you could. Burn all pcs out and have them insulated and fabbed within a hour.

03-26-2009, 05:06 PM
Yeah I never thought of having a shop make the parts and you could put them together. Good Idea!! dupree

03-29-2009, 12:30 PM
sheet metal is a certified trade for a reason..
i do not recommend non certified people making items such as duct and such me heating and ventilation requirements..
for legal and health reasons..
sorry to be a stick in the mud.
you would not let your mailman take out your appendice would you?

03-31-2009, 01:45 AM
I heard bof a slam bang mechanix who turned on a unit and all the ductwork failed! How come that happened! You need to go to school and do the work. What is your goal? You can't possibly get enough info off the internet to get skills needed for HVAC & Sheetmetal. I was a mechanic for 22 yrs and don't know it all yet! Your setting yourself up for failure! Your not just toying with us are you?