I have been thinking about a metal bender for some time. There are lots of excellent DIY ones on the web. Then I noticed that my drill vice had removable jaws and thought that not only would this save me making the screw mechanism, but it would also save space in my teeny tiny workshop.
While all the benders work in fundamentally the same way, I liked the Mistry tools version I saw on YouTube and used his rollers and handle as the basis for mine.
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Step 1: Tools and Materials
Vice with removable jaws
6301 2RS bearings x 4 (for a smaller version you could use skateboard bearings)
40mm diameter steel rod, about 25mm long
2 x M12 bolts about 40mm
2 x M5 bolts about 35mm
M12 bolt with allen key head 60mm
Skateboard wheel (or other handle)
M8 bolt 40mm
Angle iron 50mm x 50mm x 5mm, 2 pieces the same length as your vice jaws
Steel for handle. Mine was 50mm x 5mm, approx 150mm long
Drill (preferably drill press) and bits
Tap and die set (mine was a cheapo), although you could just use bolts if you haven't got one.
Angle grinder, or hacksaw and patience
Centre finder (cheapo, but you can make them or figure it out).
The usual stuff; hammer, spanners (wrench?), oil, cups of tea
Step 2: A Man Walked Into a Bar
Cut your steel for the roller to 25mm (or at least the width of 2 of your bearings). It needs to be fairly flat, the bottom needs to be very flat or it won't spin properly.
I put some blue on the bar and scratched a mark with calipers. Then I cut it with an angle grinder and flattened the top with a file. I checked it was level in my (big boy) bench vice.
Step 3: You Know the Drill
Mark the centre of the top of the rod ('top' because the bottom is the flattest piece). I use blue because it's excellent. You could use a sharpie.
Use a punch and make a dent in the centre. Be accurate!
Drill a pilot hole then work your way up to 12mm. Go slow, use lube.
Step 4: Can You Handle It
I forgot to take photos of this step, but this picture shows you the general idea.
Make 2 bends in the steel allowing enough enough room at either end for the rod and the wheel. I did this by putting 400mm in the vice and using a hammer to get the bends. Make sure that both ends are parallel to each other.
Drill a 12mm hole for the rod/wheel in one end, and 8mm for the skateboard wheel handle at the other.
Drill 2 5mm holes to attach the handle to the rod. They need to allow enough clearance for the M12 head, and not hit the outside of the rod. Mark carefully.
I realised too late that the handle didn't have sufficient clearand over the bearings to work. So I drilled out an M12 nut to 12mm and used it as a spacer in the handle.
Step 5: Drill and Tap
Put the M12 bolt through the handle and rod and ACCURATELY mark the small holes on the rod. Then drill and tap them. Again, use a punch and pilot hole first. Go slow and use lube. No jokes please...
My chart says to use a 4.2 drill bit for a 5mm tap. So I did...
Tap a thread into them.
Step 6: It Is a Great Thing to Know Your Vices - Marcus Tullius Cicero
Once again, in the general excitement in my shed I forgot to photograph this step, but it's pretty self explanatory.
Cut the angle iron to fit your vice jaws.
Remove your vice jaws and mark the screw holes in the angle iron. Make sure they will fit flush. Drill and tap a thread into them.
Screw the angle iron into the vice, close up the vice until both sides meet.
Using the bearings as templates, mark where you want the rollers. Make them evenly spaced. Draw around them and in the centres. Do the same with the rod, making sure it is between the rollers evenly, and allow enough room from the edge to allow a nut to fit on the bottom.
Now you will to mark the tops of both pieces to make sure that the jaws can close fully. The bearings side needs a gap in the middle for the rod side can project into it. The bearings and the rod themselves need to be fully supported by angle iron to spin properly.
Photos would have been so helpful here...
Step 7: More Drilling, More Tapping
Drill and tap the bearings side. M12 tap needs a 10.7 drill bit. Or you could use nuts.
I originally tapped the rod side, but found that it was actually better to drill a 12mm hole and use a nut (the bolt tended to undo in use with the tap).
Now you can bolt in the bearings. They should spin okay.
Step 8: Skater Boy
I decided to use a skateboard wheel for the handle. It's easy, the bearings are already there. And a crap skateboard was only £12 on Amazon and I can use the rest of it in other projects. Goal!
To make the 'handle' spin freely, I popped out the top bearing and added it to the bottom. Use the M8 bolt and nut to attach it to the handle.
Step 9: Let's Bend!
The finished item works a treat.
There are a gazillion clips and pages showing how to use a bender, but essentially:
1. Pop your metal in, tighten the vice a bit and roll.
2. When you get almost to the end, tighten a bit more and roll in the other direction.
3. Keep going until you have the radius you want.
4. Cut off the straight ends and roll into a circle.
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