Hello Tiger,
Very nice to meet you at Llanberis, I really enjoyed the whole Show, looking forward to the next one.
Bending Brass tube is very easy, IF, you do things right.
Annealing the Tube
An ordinary Gas stove, or a good source of flame that is similar to a stove will do.
Heat the tube to a just visible dull red, quench the whole tube quickly into cold water.
Do not clean, or bend the tube in any way, if it comes out of the water with a slight bend do NOT straighten it out.
You will need a former to bend the tube around, for the examples I have shown in the photo, I used the handle of a sweeping Brush.
Set the former firmly in front of you, place the tube at the back of the former, with your fingers at each end of the tube,
PULL and BEND the tube round the former.
Don't pull too hard, or the tube will flatten out as it bends, not enough pull will allow kinks to form on the inside of the bend.
Just needs a steady tension on the ends of the tube.
Bend the tube in one steady motion, if you have to stop while bending, do the annealing again.
When the bend is to your liking, then is the time to clean and polish if required.
The tube in the photo is 3.5 mm diameter and the open ends are 25 mm apart.
I have used them as Pulleys for years, not as good as a real ball raced Pulley, but a whole lot cheaper !!.
John,