
We had a race car, we had some new fiberglass bumpers, but sadly, we didn’t have a way to join the two. So, using some simple tools and methods, we made our own bumper brackets.
We had a race car, we had some new fiberglass bumpers, but sadly, we didn’t have a way to join the two. So, using some simple tools and methods, we made our own bumper brackets.
In reply to pinchvalve (Forum Supporter) :
Yes, it would make them stronger, and yes, in this case it's probably overkill. Those bumpers aren't doing anything structural--they're just cosmetic and weigh very little. The brackets will outlast the bumpers in an incident.
Good article and informative. I liked the drilling of the 1/8 inch holes at the corners--makes for a reasonable corner and no stress risers either--good points indeed. It seems that brackets I make typically involve welding since they are thick and I don't have a means to bend thick steel. This hammerform method works well for the thinner metal--thanks for the good photos and explanation.
Wow .. Neat ! I've never made anything with a hammerform. Now I wanna make something ! Is there a limit to the thickness of sheetmetal used ?
RoadRunnerKen said:Wow .. Neat ! I've never made anything with a hammerform. Now I wanna make something ! Is there a limit to the thickness of sheetmetal used ?
Depending on the material you use, it may start to crack. I've had this happen with aluminum but I suspect it was more the angle I was trying to bend to, being simply too much bending. Metal stretches, expands, contracts, usually all in the same job haha.
As for a limit, that is mainly gonna be a factor of how hard and how heavy a hammer you can swing. Metal brakes are a thing, but they're probably overkill for most of us.
It's really rewarding to make a good bracket out of a flat sheet of metal though. Sockets of varying sizes make good smooth angle hammer forms for simple brackets. =)
Nice to see someone is going to race a TR 7/8. Simple cars, and at one point there was an endless supply of boneyard spares. Since the Chinese sucked up all the scap steel about 20 years ago to build their Olympic infrastructuremost of the yards have gotten rid of anything older than 10 years. Not much to pick from now.
In reply to DWNSHFT :
The 928 is nice, but doesn't compare to the lovely red XKE in the background a couple photos further down!
Most steels can be bent, although with varying degrees of difficulty.
For aluminum, the main thing to remember is that the most commonly available aluminum (6061 and it's variations) is really bad for bending. It'll crack really bad. I usually specify 5052 instead, which is also pretty readily available. 3003 is another good bending aluminum.
The other main variable is the inside radius of the bend. A larger radius can reduce the amount of stress on a part. Generally speaking, the thicker the material being bent the larger the radius needs to be.
In reply to Triplesn8s :
We've enjoyed this car a lot, especially since it's been a racecar since the 1980s when the current driver's grandfather raced it. Rarely do you see a TR7 at a race anymore.
In addition to the fiberglass bumpers, the car has new paint and livery this year. It may look familiar.
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