Introduction: Improved Harbor Freight Metal Bending Brake

Picture of Improved Harbor Freight Metal Bending Brake

I purchased a 30" metal bending brake from Harbor Freight (model 67240) for a small project I needed to complete.
I had read pretty good reviews about the brake, which cost $59.95.
Overall, the quality looked decent when I opened the package, but what I noticed was the steel hold-down bar that secures the work piece in place to the bed while bending was a separate, loose piece of metal. Clamps were required to maintain pressure on the hold-down bar and keep the work piece secured..
I decided I could sacrifice a little bit of width on the brake (I needed about 20" clear for my project) and that I could install a built-in clamping systems which would make using the brake more efficient.
The photo shows the stock metal brake with the required clamps holding down the steel bar which secures the work piece.
I permanently mounted the brake to a plank that has a piece of wood below which can be clamped into a portable workbench. The plank has a hole in it so I can just hang it on the wall when not in use. The arms unscrew and are removable to help make for compact storage.

Step 1: Tools and Materials

Picture of Tools and Materials

I used a hand drill, a drill press and 5/16" threading tap (obtained from local hardware store).
Materials (inexpensive) were obtained from the local hardware store and are follows:
 - (2) knurled knobs with 5/16" machine screw 
 - (2) 5/16" fender washers
 - (2) 3/8" diam x 1/2" long stiff springs (approx. dimensions)

Step 2: Drilling

Picture of Drilling

The first thing I did was align the steel hold-down bar on the bed of the brake, leaving a little tolerance to the edge of the bed for the thickness of the materials I would be bending (+/- 18 gauge copper) and clamped it in place.
I then used a punch to set some dimples at the drill hole locations.
Using the hand drill, I drilled a pilot hole through both the steel hold-down bar and the bed of the brake.

Next I used the drill press to enlarge the holes in the hold-down bar for through-feeding the 5/16" knurled knob machine screw.
On the back side of the hold-down bar, I drilled some oversize holes about half-way through the hold-down bar to create a recess that the springs could compress into. 
I clamped a piece of plywood to the drill press to support the hold-down bar as I drilled it.

I guess this work could all be done with a hand drill if a drill press was not available.
The steel seemed pretty mild and drilled easily.

Step 3: Tapping

Picture of Tapping

Next I enlarged the hole in the bed of the brake to a suitable size for threading with the 5/16" tap.

Step 4: Assembly and Start Bending

Picture of Assembly and Start Bending

Lastly, all you need to do is assembly the components by putting the fender washer onto the knurled knob machine screw, put the machine screw through the hole in the top of the hold-down bar, insert the spring over the machine screws and flip everything onto the bed of the brake and screw in the knurled knobs.

The springs should be stiff enough to lift the hold-down bar off of the bed. As the knobs are tightened, the spring compress into the recesses and the hold-down bar can provide full contact for clamping down thin sheet metal.

See my next Instructable for how to make copper shutter caps using this improved metal bending brake.

Comments

BarryS78 (author)2017-05-06

Not so much. I found if I clamped the holding bar to the base outside my sheet metal, the holding bar would deform upward in the middle, causing the sheet metal to only be held by the edges. To get a decent bend, you have to clamp the holding bar THROUGH THE SHEET METAL. That keeps the holding bar down flat on the metal.

zoetropico (author)2015-09-03

This is a great idea and seems quite doable! I bought the 18" brake with the intention of modifying it in this way... Off to get the drill!

Nate Cougill (author)2012-11-14

This is quite clever! I ran into a similar problem with this model of brake, but opted for C-clamps. This would be much faster and more precise.

buirv (author)2011-03-21

I like your instructable a lot! I have the same metal brake. I used C-clamps to hold the "loose" flat bar. However, why didn't I think of your idea is beyond me. Thanks for the idea help...!

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