What grade of steel.....?

[realnutter]

I need a shaft making up to replace the crankshaft in my bottom-end that I'm using as a gearbox....

It needs to be 260mm long, and 35mm in diameter over much of it's length...

It will run in two big ball bearings, and have my primary (belt) drive pulley on it's outboard end...

So what grade of steel should it be made from?

Matt

[andrewaust]

Id say you could make it out of mild steel and take it to a metal specialist to get it hardened.


A

[Henk]

Something like steel quality C45 or C55

[XLerate]

I'd humbly suggest looking into fitting at least a center bearing as well to eliminate shaft flex? That will help any shaft to last longer rather than snapping in the center from continuous flex.

On my Suzuki GS550 'gearbox' I'll be refitting all of the original crankshaft bearings with tubing spacers between to help locating, so it will have 5 bearings on trans input shaft & no flex problems.

[gilburton]

Could I suggest you look at Kart axles?? They range in sizes from 25mm up. I don't think they come in 35mm but possibly you could source sealed bearings to suit the different inner/outer diameter. You also get a keyway. I'm talking about the hardened Kart types not the home built buggy/karts.

[Mouse]

At 35mm diameter I'd make it from mild steel but I am renowned for being a tight ass.
However I've been assisting the conversion of several electric buggies with comparable power to a small diesel and only ever made lay shafts using unhardened mild steel shaft (25mm) with a key way in to take taper lock sprockets and never had any problems. A rather crude but reliable solution.

I've been making these... (Shameless self plug)
http://dragonelectricsportscars.co.uk/c ... ic-buggies