Wendelspanswick
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Progress on the Austin Big 7 special has been slow recently as I have been distracted by other things but it has not been pushed to the back completely.
Being a bit of a control freak and wanting to do as much as I can on the car build I decided to make my own louver cutting tooling to cut the louvers for the bonnet and bonnet sides.
After fannying about with designs and ideas I knuckled down and made a set for 7" long louvers and fitted them to my ancient mechanical press, this has a limited throat of 8" but is deep enough for my bonnet and sides:
I could fit the set to my mechanical Ironworker which has an 18" throat but this would have complicated matters as you cannot vary the stroke height whereas the stroke height on the press is variable.
The bottom tooling is made up of three parts, the base plate and shaped back bar are plain steel whereas the shear bar is hardened and tempered ground flat stock as is the top tooling:
Originally the shaped back bar had the two coutersunk cap screws and a pair of dowels holding it in place but after I fitted a piece of rubber in the recess of the tooling to get better definition on the louver I noticed it had started to deform and curve so I replaced the 2 dowels with 3 M8 cap screws fitted from below and that cured the problem.
I had problems with the test pieces deforming at first, the back edge of the louver not sharp and the material was rising up so I clamped a piece of softwood batten to the back of the top tool to form a pressure plate and this resolved the issue. I need to adapt the top tool holder to hold a pressure plate so that I can do away with the spring clamps!
Finally here are a couple pictures of the louvers formed in 1.6mm aluminium sheet:
The lip of the first louver is butted up against the back of the louver tooling to give the spacing for the next louver.
At the moment the tooling is set to give an opening of 5mm which looks right to my eye, but I will play with the depth of cut to see how it looks. The sheared edge is clean with minimal burring, and there doesn't seem to be any distortion in the sheet unless I don't leave enough material at the edges.
And finally yes the press is outside and it is 3 phase 415V! When I moved workshops the press ended up sheeted over outside where the leather flatbelt rotted out. I will at some stage get it under cover, sort a new belt out and wire it up again but until then I use it by swinging the wheel by hand and pressing the foot pedal release.
Being a bit of a control freak and wanting to do as much as I can on the car build I decided to make my own louver cutting tooling to cut the louvers for the bonnet and bonnet sides.
After fannying about with designs and ideas I knuckled down and made a set for 7" long louvers and fitted them to my ancient mechanical press, this has a limited throat of 8" but is deep enough for my bonnet and sides:
I could fit the set to my mechanical Ironworker which has an 18" throat but this would have complicated matters as you cannot vary the stroke height whereas the stroke height on the press is variable.
The bottom tooling is made up of three parts, the base plate and shaped back bar are plain steel whereas the shear bar is hardened and tempered ground flat stock as is the top tooling:
Originally the shaped back bar had the two coutersunk cap screws and a pair of dowels holding it in place but after I fitted a piece of rubber in the recess of the tooling to get better definition on the louver I noticed it had started to deform and curve so I replaced the 2 dowels with 3 M8 cap screws fitted from below and that cured the problem.
I had problems with the test pieces deforming at first, the back edge of the louver not sharp and the material was rising up so I clamped a piece of softwood batten to the back of the top tool to form a pressure plate and this resolved the issue. I need to adapt the top tool holder to hold a pressure plate so that I can do away with the spring clamps!
Finally here are a couple pictures of the louvers formed in 1.6mm aluminium sheet:
The lip of the first louver is butted up against the back of the louver tooling to give the spacing for the next louver.
At the moment the tooling is set to give an opening of 5mm which looks right to my eye, but I will play with the depth of cut to see how it looks. The sheared edge is clean with minimal burring, and there doesn't seem to be any distortion in the sheet unless I don't leave enough material at the edges.
And finally yes the press is outside and it is 3 phase 415V! When I moved workshops the press ended up sheeted over outside where the leather flatbelt rotted out. I will at some stage get it under cover, sort a new belt out and wire it up again but until then I use it by swinging the wheel by hand and pressing the foot pedal release.