Roller metal bender v1

Motivation and design reference

Permanent magnet rotary generator required a bent part from aluminum rectangular profile, besides, having a roller bender is a great idea, I thought to myself. So… I looked into it and found plenty of roller benders, but only a few, that I found relatively easy to make and could fit into my tiny workshop.

The one I decided to go for, I discovered on Youtube on a channel called “Mistry MakeTool“. Here are the links to the instructions he made:

  1. Make A Metal Bender || Homemade Roller Bender ( by “”Mistry MakeTool
  2. Make A Metal Bender || Homemade Roller Bender (

First I decided to make plans for the metal bender based on the latter design, but modified for my needs as required.

Figure 1: Metal roller bender model based on “Mistry MakeTool” design.


PDF files of the roller metal bender here.

Check out other designs too.


The video of the making and assembling is available on Youtube:

Bill of materials

I divided the Roller metal bender into two parts by functionality; (A) Base and (B) Slider. The entire roler bender and the slider alone are shown in Figures 2 and 3 respectively.

Figure 2: Entire roller bender with cross-section and bill of materials.
Figure 3: Slider with shown constituent parts.

For this build you will need the following parts:

  1. Mild steel bar with 10 × 50 mm cross-section (approximately 600 mm in length)
  2. Mild steel rectangular bar 20 × 5 mm cross-section (approximately 300 mm)
  3. Mild steel L-profile 50 × 50 × 5 mm (approximately 300 mm length)
  4. Mild steel L-profile 25 × 25 × 5 mm (130 mm length)
  5. Full profile metal rod diameter 40 mm, length 56 mm (1 pc)
  6. ISO 4032 M12 Hex nut (1 pc)
  7. ISO 4762 M4×10 Hexagon Socket Head Cap Screw (1 pc)
  8. ISO 4762 M5×20 Hexagon Socket Head Cap Screw (2 pcs)
  9. ISO 4762 M6×60 Hexagon Socket Head Cap Screw (1 pc)
  10. ISO 4762 M12×45 Hexagon Socket Head Cap Screw (1 pc)
  11. ISO 4762 M12×55 Hexagon Socket Head Cap Screw (2 pcs)
  12. ISO 4762 M12×80 Hexagon Socket Head Cap Screw (1 pc)
  13. ISO 6338M12 Hex nut (1 pc)
  14. DIN 625 6301 roller bearing (6 pcs)
  15. DIN 988 S5×10 washer (1 pc)
  16. DIN 988 S7×13 washer (1 pc)
  17. DIN 7991 M5×12 hexagon socket countersunk head cap screws (10 pcs)
  18. M12 threaded rod (length 100 mm)
  19. Oak rod for handle, diameter 32 mm (length 60 mm).

Buy plans (recommended price $5.00):



First we will assemble the base of the roller metal bender as shown in Figure 2.

Figure 4: Base assembly.

Add 25×25×5 mm L-profile, which will serve as base for tensioning spindle. Additionally add 6 deep-groove ball bearings DIN 625 6301 and fasten them with a M12×55 ISO 4762 hex socket head screw as shown in Figure 5.

Figure 5: Added base for tensioning and ball bearings.

When the base is solidly built, the nut (27) that will guide the tensioning spindle (threaded rod) is welded to the base (5) as shown in Figure 6.

Figure 6: Added nut for guiding the tensioning spindle.


Next sub-assembly is the slider, which will move the sliding roller and apply tension to the bent metal. In Figure 7 the first few parts of the slider are presented while mounted on the base.

Figure 7: Parts (14), (15) and screws (20) added to the assembly.

Adding part (17) constrains the slider to the base with the screws (20). Next follows the drive roller (16), which is held in place by a M12×80 screw that is first screwed into part (15) so that there is a slight slack (approximately 0.5 mm) between the base and the roller, so that the roller can rotate around its axis. The nut (19) in the end locks the screw into place (Figure 7).

Figure 8: Added drive roller (16) with screw (22) and locking nut (19).

The drive roller is driven by the tensioning spindle (8), which goes in through the nut (27) and is held in place by a M4×10 hex socket screw (9). Two washers are added to reduce friction (21 and 10). Tensioning lever (11) is welded to the tensioning screw.

Figure 9: Installed tensioning spindle (8) and tensioning lever (11) with appropriate tools and parts.

Finally there comes the drive lever (23) with all parts to hold it in place and the wooden handle (24).

Figure 10: Added drive lever (23) with the rest of the parts.

Buy plans (recommended price $5.00):


Licensed under the TAPR Open Hardware License (

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