Sunday, April 26, 2015

Central Machinery - Sheet Metal Brake Up Grades

Tool, tools, seems like I spend a lot of time trying to figure a way around doing a particular task.  For example, a drum sander would be handy at times.  But unless making a lot of cabinet door panels on a daily basis, hard to justify.  Like wise, a sheet metal brake is not something I would use every day.  So, I have been looking around.  Something can be cobbled up with a couple of angle iron pieces to make simple bends.  However the results are not always very pleasing.  I'm not sure there is an end to the other side of the spectrum,  prices can escalate fairly quickly.  Harbor Freight has a range of benders.  The one I selected is in the middle of the price range.

 After reading many reviews on Harbor Freight tools having poor hole alignment and missing parts that made assembly difficult, I was pleasantly surprised by the Central Machinery # 91012 brake.   The brake comes in two boxes.  One for the completely assembled head and a second box for the legs and feet.  I think it took longer to cut down the boxes for disposal.  I was up and bending material.

The brake is not perfect, I found that the upper press plate would slide back as a sheet was being bent.  Not good.  I found that the locking bolt sits on the bolster of the press plate brackets.   In my opinion the the locator pins for the press plate bracket should be moved about 1/2" forward.  Not impossible to do, but an easier approach is to cut down the shoulder.  The drawings in Project 3 show the details.  Maybe Harbor Freight can ultimately address this issue.

I also found that adjusting the upper press plate for various thicknesses of material was awkward.  Finger tighten the bolts and tapping with a rubber mallet was not going to work.  So, in Project 3 I use a half of a pair of pipe clamps to make the adjustment a screw motion.  As a side note, I used 3/4" pipe clamps because this is what I had on hand.  1/2" clamps would work just the same at a lower overall cost.

The brake is over 100 pounds and I don't have the space to bolt it to the floor.  Projects 1 and 2 add wheels for mobility and cross bracing to prevent the feet from shuffling laterally.  Obviously if you plan to bolt the brake to the floor, wheels are not needed.  I used 4 bolt plate mount wheels that required I cut off the existing plate and welded on a new one.  The supplied lower plate is just attached with a couple of spot welds.  So, I am not sure this will work directly.  I did look at using center stud wheels mounted through the floor bolt hole.  Some additional reinforcement may be needed.

Project 4 came about because I had the sliding ends of the pipe clamps left over.  The drawings show a simple build up for a depth stop.  Current minimum is 4".  I plan to make an extension plate that will reduce the stop depth to 1/2-3/4"

I am always trying to clean out the closet.  So, I used what I had on hand first.  However, all the materials for these up grades are available at a big box hardware store.  You may get your exercise for the week, since the parts are in electrical, plumbing, tools, fasteners, and miscellaneous hardware.  I used a drill press, wire welder, heavy duty 1/2" hand drill, and right angle grinder to make these up grades.

Following are the drawing and details of the project.  I had some other ideas as well, but there a number of things needing bending first.  Have fun.

Disclaimer – Determining suitability of the modifications described here or skill levels needed to make these modifications is solely the responsibility of anyone choosing to replicate the modifications.  There is no intent to criticize the Harbor Freight products described here.  Please be advised, the suggested modifications have not under gone any safety review or risk assessment.  Proceed at your own risk.  These modifications are not approved by Harbor Freight.  Moreover, Changes to the Harbor Freight items would probably void any warranty by Harbor Freight.  


  1. It’s a pity you don’t have a donate button! I’d definitely donate to this brilliant blog! I guess for now i’ll settle for book-marking and adding your RSS feed to my Google account. I look forward to fresh updates and will talk about this site with my Facebook group. Chat soon! locfome round duct machine

    1. Thank you - glad you like the brake modifications. I would be happy to chat about any comments or questions.