Making copper reducers/funnels
Posted: Wed Jul 09, 2014 8:34 am
Quick tutorial on how to make your own copper reducers/funnels. This can save you a fair bit of money.
You will need:
- Paper and pencil
- Copper sheet (or flattened pipe)
- Compass (not the direction kind)
- Ruler
- Good pair of tin snips
- Brazing equipment
This tutorial uses an example reducer size of 100mm down to 25mm (4” to 1”), with a length of 50mm. Length in this case is the distance between the lip of the small hole to the lip of the larger hole if you were putting a ruler along the reducer.
1. Draw a horizontal line, the length of your larger diameter (100mm in this case). Mark the centre.
2. Measure at a 90degree angle from the centre mark to a distance the length of the reducer (50mm here). Mark this point.
3. At the mark you’ve just made, draw another horizontal line, the length of your smaller diameter. Make it such that the centre of this line is on the mark.
4. Connect the 2 centres of the horizontal lines with a vertical line
5. Draw a line connecting the ends of the short and long horizontal lines, continue the line until it passes the centre points.
6. Extend the centre vertical line until it crosses the line you just drew
7. Place the compass pin onto the crossing point of the 2 lines you just drew in steps 5 and 6. Place the compass pencil onto the edge of the small horizontal line. Draw an arc, about 180 degrees. Repeat for the large horizontal line.
8. Work out the circumference of the large pipe size, this is π×D. So in this case, the circumference is 3.14×100=314mm. Divide this into a number of sections (the bigger the number, the more accurate you’ll be). In this case I’ll use 20. So 314/20=15.5. Set the compass distance to 15.5mm then walk the compass from the end of the large horizontal line, along the arc until you count 20 steps. Mark this point.
9. Draw a line connecting the mark in step 8 to the middle mark.
10. You’re done, cut out the grey area, then use it as a template for your copper plate, cutting out with tin snips. To shape the copper once it matches the template, gently hammer it around a piece of tube, then braze it together.
You will need:
- Paper and pencil
- Copper sheet (or flattened pipe)
- Compass (not the direction kind)
- Ruler
- Good pair of tin snips
- Brazing equipment
This tutorial uses an example reducer size of 100mm down to 25mm (4” to 1”), with a length of 50mm. Length in this case is the distance between the lip of the small hole to the lip of the larger hole if you were putting a ruler along the reducer.
1. Draw a horizontal line, the length of your larger diameter (100mm in this case). Mark the centre.
2. Measure at a 90degree angle from the centre mark to a distance the length of the reducer (50mm here). Mark this point.
3. At the mark you’ve just made, draw another horizontal line, the length of your smaller diameter. Make it such that the centre of this line is on the mark.
4. Connect the 2 centres of the horizontal lines with a vertical line
5. Draw a line connecting the ends of the short and long horizontal lines, continue the line until it passes the centre points.
6. Extend the centre vertical line until it crosses the line you just drew
7. Place the compass pin onto the crossing point of the 2 lines you just drew in steps 5 and 6. Place the compass pencil onto the edge of the small horizontal line. Draw an arc, about 180 degrees. Repeat for the large horizontal line.
8. Work out the circumference of the large pipe size, this is π×D. So in this case, the circumference is 3.14×100=314mm. Divide this into a number of sections (the bigger the number, the more accurate you’ll be). In this case I’ll use 20. So 314/20=15.5. Set the compass distance to 15.5mm then walk the compass from the end of the large horizontal line, along the arc until you count 20 steps. Mark this point.
9. Draw a line connecting the mark in step 8 to the middle mark.
10. You’re done, cut out the grey area, then use it as a template for your copper plate, cutting out with tin snips. To shape the copper once it matches the template, gently hammer it around a piece of tube, then braze it together.