Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
(OP)
Hello! First time posting, only just joined today but would like some help with my project please?
Please see the picture below. I'd like to create this 'spring' so that it give the skateboard a bit of 'suspension' but so that it also doesn't twist when the rider tries to turn. ie. It can still twist the trucks as it would do bolted to the deck.
The dimensions are somewhere in the region of 55-70mm wide flat bar 3mm thick. What I intend to do is heat up a length (just heat up a section about 25mm wide from edge to edge) until orange, then bend around a form to make the arc, then quench in oil. Heat up again to orange, then quench again.
Would this (in mild steel) give it enough strength to be a 'spring' of sorts, so that it can bend but return to it's shape, and also when the board leans, won't tortionly twist the flat bar out of shape?
Any help, feedback or suggestions are greatly appreciated :)
Please see the picture below. I'd like to create this 'spring' so that it give the skateboard a bit of 'suspension' but so that it also doesn't twist when the rider tries to turn. ie. It can still twist the trucks as it would do bolted to the deck.
The dimensions are somewhere in the region of 55-70mm wide flat bar 3mm thick. What I intend to do is heat up a length (just heat up a section about 25mm wide from edge to edge) until orange, then bend around a form to make the arc, then quench in oil. Heat up again to orange, then quench again.
Would this (in mild steel) give it enough strength to be a 'spring' of sorts, so that it can bend but return to it's shape, and also when the board leans, won't tortionly twist the flat bar out of shape?
Any help, feedback or suggestions are greatly appreciated :)





RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
1) using an alloy designed to be used as a spring (i.e. spring steel of some kind)
2) making that bend a complete 180o and putting the trucks where they normally go on a skateboard. Your board as shown doesn't allow the rider very much weight transfer between the front and rear axles, which is a thing you need on a skateboard.
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
When you say weight transfer, what do you mean? I have the trucks already bolted to the kick tails on some angled risers to get the trucks back to almost horizontal, and that at the moment is a great riding position, am able to ride and turn well with ease.
I was just hoping this 'spring' might be able to give a smoother ride...
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
Why did you not mount the trucks where they normally go?
Maybe you're trying to accomplish something specific. In that case, carry on. It's just an odd looking skateboard.
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
I was given this board and now have 180mm trucks on it with 97mm flywheels, it's basically going to be for crusing and be electrified like my other board.
If the trucks are mounted where they normally go, with the large wheels and short wheel base it's crazy easy to accidently fall off backwards and not very stable for cruising, which is why I've mounted them on the tails, to create a longer wheel base.
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
If they are the same size all steels will flex the same amount.
The higher strength the steel is the further it can flex without permanently deforming.
You can probably test with mild steel, but in service you will need something much stronger.
To make this tight of a bend in spring steel you will need to bend it hot, and then HT afterwards.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
I then intend to heat the whole thing up until orange and do the same thing again (quench in oil) to anneal the whole thing.
How many times would you recommend I do that to make it keep it's shape whilst still being able to 'spring'?
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)
RE: Flat bar 'spring' with sideways torsion stiffness (Metal Noob)