Making a Robust Metal Bending Machine From 100% Recycled Metal
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Is your workshop missing some tools, like a metal bending machine? Then, instead of buying a commercially made one, why not make one from scrap metal and a little bit of elbow grease?
If this sounds of interest, then follow this simple guide to making one for yourself.
As you can imagine, like any project of this nature, you'll need some tools and materials before you get started.
Materials and gear needed
- Old gears
- Scrap metal plates and bars
- Tubular steel lengths
- Brass rods
- Masking tape
- Metallic spray paints
- Screwdriver set
- Basic tools (wrench, screwdrivers, etc)
- Various nuts and bolts
- Angle grinder
- Mini lathe
- Belt sander
- Welding gear and safety equipment
With all the tools and materials in hand, it is time to get stuck in with this epic build.
Step 1: Clean up any metal parts
The first step is to gather together any rusty or old metals parts, like gears, etc. Grab your angle grinder, and clean off any rust and polish the pieces to expose the bare metal underneath. Also, take the time to cut off any poking-out pieces that are not needed like old bolts.
You may find it easier to mount the pieces in a lathe, but we'll leave this to your judgment. As per usual, ensure you wear protective hand and face gear to protect your precious skin from flying sparks of hot metal.
Step 2: Machine the other parts needed
With that done, take your brass rods, secure them in your lathe, and machine them into large flanges. As you'd expect, make the bore of the flange using a pilot hole first, and then widen progressively until you reach the size you need. Also, take the time to polish the piece while it is in the lathe.
Rinse and repeat to make a second beveled flange as shown in the video. The dimensions of the bevel should match the bore of the hole in the gear center disk.
The other flange will be used to mount the two brass flanges together on the gear.
Next, take the flanges, and mark out a number of equal points around the circumference of each to match any mounting holes around the center disk of the gear. In this case, there are eight.
Drill holes through these points so that the flanges can be bolted to the gear.
With that complete, take a piece of aluminum or steel disk, and machine it into a large beveled disk with a radius of 3 and 15/16ths of an inch (10 cm). Excavate a hole through the very center of the disk and widen as needed.
This piece will be placed on top of the gear, so it will need to have a negative profile of the surface of the gear underneath so that they can sit flush together. The central hole needs to be to the same dimensions as that of the gear and flanges.
Note that this piece will one of three of varying diameters to give you options for the angle of bend you want the machine to be able to produce.
Next, take another disk of aluminum or steel, and machine it to a radius of 2 and 61/64ths of an inch (7.5 cm). Again make a negative of the profile of the gear to one side and bore a hole through the center to match the dimensions of the gear's center hole. Bevel to the top of one side.
Next, take yet take another disk of aluminum or steel, and machine to form a cylinder with a radius of 1 and 31/32ths of an inch (5 cm) with a wide rim at the base with a radius of 2 and 61/64ths of an inch (7.5 cm). Again make a negative of the profile of the gear to one side and bore bolt holes through the metal discs so that they can be mounted to the main gear.
These parts will be switched in and out of the metal bending machine as needed. Each will be secured to the main gear using the brass flanges you previously made.
Step 3: Mount the machined parts to the gears
With your freshly machined parts, maneuver them into position on the large gear and check how they mount to the gear using suitably sized nuts and bolts. Ensure you also add the brass flanges below the metal disks.
Depending on the dimensions of the nuts, you may need to refine the shape of the brass flanges, or indeed the nuts to fit. For best results, use a belt sander to complete this task.
Once the bolts are securely fastened to each piece, weld them into place as needed. It goes without saying, but please ensure you take the necessary precautions whenever you weld.
These nuts will be used as the main mounting points for switching in and out the larger metal disks.
Step 4: Build the bending mechanism
With that complete, the next step is to find another smaller gear with the same sized teeth as the main larger gears. You may need to dismantle old pieces of machinery (like motors) to find some, or, alternatively, source and buy some.
Once in hand, take a sheet of scrap metal. Place one of the main wheels and the smaller gear (both engaged) onto the plate so that the can be mounted to it.
With that done, mark out the position of their central holes, and bore suitably sized holes through the plate. Also round off the corners of the plate as needed using an angle grinder and belt sander.
Once complete, place the main mounting "axle" bolt for the larger gear into place and weld it to the plate. With that done, make a shaft and mounting flange for the smaller gear, and weld that into place on the plate.
You will want the main gear and smaller gear to move freely, so bear that in mind when welding.
With that done, take a smaller length of scrap metal, clean up, and round off the corners as needed. Next, bore a hole to one end, and cut/route a wedge roughly halfway down its length.
With that done, hammer the ends towards each other to form a right-angled piece of metal. This piece will sit above the smaller gear we previously installed on the larger metal plate and act as a shaft support/bracket for the gear.
Weld the join as needed. With that done, machine a longer cylinder/shaft of metal using your lathe to match the bore of the hole in the right-angled piece of metal you just made.
It will need to move freely within the hole, so ensure its diameter is ever so slightly smaller. Bevel the exposed end slightly, and remove the cylinder from its source block.
With that done, secure the shaft back into the lathe, place the small gear at the free end of the shaft, and secure it into place with the tailstock. Turn on the lathe, and squeeze/sand fuse the pieces together.
With that done, take the shaft and gear, place it back onto the main metal plate, and then weld the shaft support piece into place on the base plate.
With that done, take a bar of steel, and cut it down to 15 and 3/4 inches (40 cm), or so, in length. Next, mark the center point of the bar using a scribe.
Round the corners of the bar using your belt sander, and clean off any rust, as needed. With that done, take the small gear and shaft assembly you created earlier, and place it in the center point of the bar.
Weld it into place, as needed. With that done, replace the shaft and gear to the main assembly. The bar should be able to freely spin above the main gears.
Step 5: Make the bending machine bar restraints
Next, take another few lengths of scrap metal (one thinner than the other). Mock them up into place next to the main gear, with the smaller length at the bottom, and larger plate to the top.
Clean off any rust, round off the corners, and shape the wider piece of metal so that it sits above the teeth of the main gear. Cut out a small section as needed to allow the raised part of the main gear to rotate freely.
With that done, weld the thinner length of metal into place on the main base plate. This will serve as the mount for the larger plate. With that done, position and weld the larger plate into position.
This will form the guide rail for the piece's main metal clamp. With that done, jerry-rig other pieces of metal to form the main adjustable clamp for varying the angle to metal bend when the machine is complete.
With that done, take another of the large gears, and another piece of scrap metal. Route the gear to accommodate the width of the scrap piece of metal.
Next, cut down the metal strip to size and bore two holes to one end of it. The metal strip should be able to sit in the routed groove of the gear and touch the wide-based metal central hub piece you machined earlier.
Weld the gear and metal bar together. Build another adjustable clamp for the bar of the main gear, as needed.
Next, take some tubular steel, and mark out lengths to the same width as the main base plate. Cut the tube down to size, and clean up the cuts as needed.
Next, place the pieces onto the underside of the main machine's base plate, and weld them into place.
With that done, take some clamps, and clamp the metal bending machine into place on the edge of your worktop.
Step 6: De-grease and paint the machine parts
Next, take a solvent, like acetone or grease cleaner, and clean up all the metal parts as needed.
Clearly do this in a well-ventilated space, and wear gloves and a mask to avoid irritating your skin and lungs.
With that done, decide if, and where, you want any of the parts of the machine to be painted or left as bare metal. Tape off any areas you don't want to be painted with masking tape, and then spray paint, or hand-painted, the metal parts as required.
Leave the paint to fully dry and peel off the masking tape. With that, the main components of this DIY bending machine are now complete.
Step 7: Give the metal bending machine a test drive
With the main components now built, the final step is to set up your metal bending machine and test it out.
To do this, mount the main base plate to the side of your workbench using its clamps. Next, grease up all the moving parts of the machine, as needed.
With that done, install the main winding gear part, and then install the main gear and secure it into place on its plate-mounted axle with its brass flange and mounting nut.
With that done, take one of the central metal bending hubs, and mount it to the main gear.
With that complete, installed the guide rails and clamps for the base plate and main gear. Tighten the bolts and nuts as needed.
Next, take a test length of metal, and feed it into the machine. You can now test the machine by gradually turning the handlebar and watch the metal bar bend accordingly.
Congratulations, your DIY metal bending machine is now complete and fully functional.
If you enjoyed this DIY project, you may want to consider getting some other "heavy metal" tools to add to your inventory. How about, for example, restoring some veteran tools?