DIY Sheet Metal Bending Brake ~ Part 3 ~ It Works!

It has been a long time of no progress on my homemade, DIY sheet metal brake. But now that the push on the interior walls is over, I have had some time to work on the project.

You can catch up on previous work on the brake at Part 1 and Part 2.

I have good news to report: It works!

After my Part 2 entry, I lightly tack welded the “hinges” in place. I made the hinges from three-quarter-inch diameter, three-inch long bolts with three nuts. You can see in the next photo that I used the angle grinder to grind away the I-beam to allow two of the nuts to rotate on the bolt:

Then I cut away part of the angle iron to receive the bolt on the part of the brake that swings up to bend sheet metal:

By the way, the angle iron pieces are stamped with the name “Sheffield Steel,” a foundry in business in Ohio since 1955. I got the steel from a building that was being demolished at the old U.S.Air Force, Howard Air Force Base just outside of Panama City. So I have a piece of history right here in my shop.

Next I temporarily clamped the angle iron in place and welded, little by little, the bolt and nuts in place. I kept testing to make sure that the angle iron would swing on the hinge. In the next photo is the completed hinge assembly. Also notice that I had to build a truss to keep the swinging angle iron in a straight line and to keep it from deflecting:

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UPDATE JAN 2016 ~ Several people have asked for better photos of the hinge. Here are two recent photos showing how I welded the bolt head and the nuts to the brake body and the hinged part:

P1030569-001 P1030571-001

There has been some wear and tear on the machine in the past couple of years!

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I slapped on a few coats of paint to keep the rust at bay, then took the brake out for a test drive. For the first bend, I cut a strip of 26-gauge sheet metal to make inside corner trim for Cynthia’s studio:

Here’s a video of one of the first bends; the material is thin, 26-gauge galvanized steel. I’m sure the brake will bend heavier gauge, but probably not in full eight-foot pieces.

Here is a close up of the action of the hinge:

I’m slap-a-knee darn happy with the ease of operation of the brake and the nice sharp line of the bend it makes. I know that all my welds aren’t professional quality, but hey, I’m easily bending eight-foot-long sheet metal in my shop for less than $150 in materials vs. $2,500 or more for a commercial brake. Makes me smile.

I still want to make a press brake in the space below the sheet metal brake, for bending heavy-gauge bar stock. So watch for that post any year now.

And then am I done? Well, no. Cynthia has asked if I can upgrade the cabinet that I made to hold her 1,500 watchmaker’s tins that store her vast collection of seed beads for making necklaces and other items. I made the cabinet out of wood and the termites have been having tailgate parties on each of the 48 plywood drawers.

“Could you make drawers out of sheet metal?”

“Well yes, dear, but I will need to make a box and pan attachment for the brake.”

As it stands now, my brake can bend angles in one direction only. A box and pan attachment allows for bends in two directions, as in bending an open-topped box or drawer. So it is off to the drawing board for the next part of this project.

In other news: We are seeing signs of the end of the rainy season. As we do every year, we got hammered with rain pretty hard in November. But now the tell-tale alternation between wet days and sunny days is becoming more common. Around the fifteenth of December the rain will stop as if a switch were thrown, and the Tourist Season will begin.

Why all the rain in November every year? There is a band of low pressure that circles the globe. This band moves up and down over the equator twice a year, delivering heavy rains as it passes over Panama. It is called the Inter-tropical Convergence Zone (ITCZ).

You can see the ITCZ passing over us in this recent screen shot from The Weather Channel (Panama is the little arch of land between Costa Rica to the west and Colombia to the east). The right-most orange cloud was just about over us at the time posted at the bottom of the picture:

That’s all for now. Thanks for stopping by.

 

 

DIY Sheet Metal Brake ~ Part 2

I’m delighted by the progress I am making on my DIY sheet metal bending brake. There will be a Part 3 and more before I am done, but here is progress so far:

The Down Clamp: Since writing Part 1 I have successfully fabricated the Down Clamp. This is the piece of 1/4″ thick, 3″x4″ angle iron at the very top of the brake. Any sheet metal to be bent slides under this clamp. The clamp is then pressed down to hold the sheet metal in place.

I should note here that I had to make a decision about how to hold the Down Clamp down against the I-beam. Most professionally-made brakes use a rapid cam-action lever. Very nice, but DIY fabrication of a cam mechanism seemed complex. And as I will use the brake only infrequently, I decided on a simple nut and bolt affair.

Back to fabrication of the Down Clamp: First, I made a notch at either end of the angle iron to make room for the hinges (I have already planned the hinges). Then with the angle grinder and a drill bit, I made a three-quarter inch hole at each end of the angle iron. Next I welded a five-eighths inch hex-head bolt upside down on the I-beam. I dropped compression springs over the bolts. Here is one of the bolts welded to the I-beam:

Then I placed the angle iron, with the big bolts coming up through the holes. I put nuts on the bolts and cranked the angle down all the way. As I predicted it might, the angle iron deflected upwards at the middle. Not much, but enough that the sheet metal would not be held firmly in place. I had already thought that a strengthening truss would be needed.

I unscrewed the nuts and placed a one-eighth inch spacer under either end of the angle, then bolted it back down. At the middle of the angle, I used a couple clamps to pull the angle iron down to the I-beam, thereby creating a very small center-downward arch to the angle iron. Then using five-eighths inch rebar, I went about fabricating and welding a truss onto the angle iron. When I was done, I removed the clamps and spacers and ta-da… the angle iron held its little arch. As I screwed the nuts down, the arch in the angle iron compressed and mated perfectly with the I-beam. I was not able to see any light passing between the angle iron Down Clamp and the I-beam and it firmly held a piece of paper everywhere under the clamp. I breathed a big sigh of relief and did a happy dance because this was one of two mission-critical parts of fabricating the brake. (The other mission-critical part is the pair of hinges.)

I finished the Down Clamp fabrication by welding on an adjustment bolt for aligning the front of the Down Clamp with the front of the I-beam. In the next photo you can see the Down Clamp front edge alignment bolt. The nice thing about this being adjustable is that for steel sheet metal, which can take a nice sharp edge, the Down Clamp can be set precisely just a tad (the thickness of the sheet metal being bent) back from the front of the I-beam. However aluminum wants a more rounded corner or it will crack, so I can back off on the bolt and the Down Clamp will move backwards a little bit more (thickness of the aluminum plus a whisker or two), giving more room for the aluminum to round over. Here is the front edge alignment bolt at the lower right corner of the next photo:

I’ll replace the long carriage bolt with a shorter hex-head bolt. I may weld a tee handle on the new bolt to make tool-less adjustments.

The Hinged Angle Iron: The next big part of the project is to attach hinges to the other piece of angle iron so that it can swing up and bend the sheet metal. This is going to be a delicate operation as the hinges must be positioned perfectly. If the hinges are even a fraction off center or a tiny bit crooked, the bending operation will be faulty.

Recently I spent a lot of time at the Discovery Center in Panama City, looking at hinges and also at things that are not hinges but could be if I thought outside of the box. All the hinges, dozens of different styles and types, had potential flaws. Most were not strong enough, allowing for stretching or bending of the hinges. Others were not accurate enough, allowing for slop to enter the process. Even others wouldn’t allow the alignment axis that I need. I’ve seen good DIY hinges on other peoples’ brakes, but I couldn’t find tubes and pins that would mate closely enough to make a good homemade hinge.

Finally it dawned on me. The LED light bulb above my head turned on. How about using a bolt with a bunch of nuts? If you put a bunch of nuts on a bolt and tighten them, the bolt won’t turn. But if you leave a small space between the nuts, the bolt will turn. Or more correctly for my application, the nuts will spin on the bolt. And the action is quite smooth and accurate. I picked a few parts out of a few of the hundreds of bins and started making mock ups. I settled on beefy three-quarter inch, three inch long bolts with three nuts on each bolt. I can weld every other nut (and the bolt head) to the two pieces of steel to be joined by the hinge. Here is a photo of my imagined hinge:

Next I will cut very accurate notches (to accept the hinge) in the I-beam and the angle iron, then weld the hinges in place.

But sorry, that will have to wait for another day as more pressing tasks are calling for my attention.

In other news: The front garden is doing well. The weeds are doing too well, but we are trying to have a ground cover, a pretty little plant with blue flowers, do battle with the errant morning glory weed menace. Here’s a garden photo:

At the far end of the garden we left a tree stump, and have been seeding it with bromeliads and orchids:

We are nestling plants in every nook and cranny of this old stump.

One of the orchids is in full bloom:

I’m sure that others will be flowering in due time and I’ll post an update.

That’s all for now. Thanks for stopping by.

Bending Under Pressure ~ I Need A Brake! ~ Part 1

No, I didn’t make a spell-o. I really did mean to write Brake, not Break.

A brake, or Sheet Metal Bending Brake is a piece of shop equipment that facilitates bending angles on sheet metal. They can be quite small and portable like in the next photo (source):

Or they can be industrial giants like this wowser (source):

You can purchase brakes for the hobby or small shop like this (next photo) floor model from Grizzley for about $2,050 delivered in the States:

The above brake is nice, but allows for bending metal only 48-inches long. I’d like to make sheet metal trim twice that, or 8-feet long. Can you imagine the price of this hundreds-of-pound tool delivered here in Panama?

What’s a (cheap frugal) guy to do?

DIY!!!

A sheet metal bending brake like I would like to own develops massive forces, as in thousands of pounds of pressure, to bend steel and aluminum. I knew my DIY brake would have to be VERY BEEFY or the tool would bend out of shape and simply not perform. Hmmm.

Ahaaaaa!

A year or so ago I had the opportunity to pick up some used steel I-beams. We needed them to support the crane in the mud as the containers were placed on the support columns. But beyond that I had no clear vision as to what I would do with all this steel of varying lengths from 2-feet to almost 9-feet long.

I went into container #1 where I was storing the beams. I measured and pondered, even going so far as to bringing a 5-gallon bucket into the container to use as a chair while I pondered. Yes, I determined by rule of thumb, the beams were big enough, perhaps even massive overkill. Cool. Building a shipping container house, I like overkill.

Now that I had a project in mind, I also bought a couple pieces of used, heavy angle iron.

The metal was rusty and pitted and needed a good cleaning and initial prime coat of paint to keep it from re-rusting while I spent weeks working on the project. Here is how I started:

The beam on the right needs cleaning. The one on the left is all cleaned and prime painted.

To clean the steel I used an angle grinder with a grinding disk and another grinder with a wire brush:

The grinder worked well, but the wire brush deteriorated too fast, and the flying wire bristles are no fun when they stick into your arm or Jabo’s paw. So I switched to a sanding disk, and it worked like a charm to remove the fine surface rust:

“So”, you ask, “how big is this brake going to be?” Here’s a clue; So far I have the three beams that will make the base. I wanted the cross beam to be a bit elevated so the whole mess wouldn’t rock and roll on any high spots in the floor, and also so I can blow the floor clean with the air hose. So I cut notches in the vertical web so that middle beam would sit on top of the side legs:

Hey Fred. Why’s your shop so cluttered? It was time to clean the last of the bits and pieces out of container #1. The stuff sat on the floor of my shop until I could make shelves in the little alcove next to the front door. The shelves are now done but no photo yet.

Next I cut two, 4-inch square tubes for legs. I turned the top I-beam upside down and welded the legs to the beam. I did this outside of the shop, then slid the heavy assembly into the shop on planks. Then I turned the beam/leg assembly right side up and welded the legs to the base. I can barely lift one end of this monstrosity.

In the next photo, a piece of angle iron is sitting on top of the I-beam. When the tool is completed, the angle iron will lift a bit so I can slide the sheet metal between the two. Then the angle iron will be clamped down for bending the sheet metal:

Let me diverge for a moment. The bending brake will be really swell, but there is another opportunity here. There is a related tool called the press brake. The press brake uses hydraulic action to bend heavier steel plate. A small press brake can easily bend one-quarter-inch steel, so if I had one, I could make all kinds of brackets and do-dads. Here is a photo of another guy’s homemade press brake (source):

I recently purchased a 30-ton hydraulic jack, so I figure I can build a small press brake in the rectangular space between the bottom cross I-beam and the top I-beam. You can see the jack sitting on the floor beyond the brake:

I am about to start work on the top piece of angle iron. I’ll call it the Down Clamp. To accomplish a sharp bend in a piece of sheet metal, it is important that the Down Clamp and the long I-beam mate perfectly together. In the next photo you can see that the angle iron for the Down Clamp has a high corner where it contacts the I-beam. That corner needs to be ground away. I’ll do that next:

The next part of the project is to make arrangements to lock the Down Clamp firmly in place. Also, I need to attach another angle iron that will serve as the piece that swings up and bends the sheet metal. The swinging part, I’ll call it The Swinging Part, will be under tremendous forces; the hinges will have to be quite stout so that they don’t bend or stretch. Also, the hinges have to be perfectly welded in place so that no slop is introduced during bending of the metal. I’m engineering that in my head now. That and the rest of the construction of Fred’s Pretty Big Sheet Metal Bending And Steel Plate Press Brake will have to wait until Part 2.

So how big is it going to be? Pretty big. And so far, I have $130 in the metal and another $30 or so in the hydraulic jack. Not bad.

That’s all for now. Thanks for stopping by.