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To add to that bit, on my old bar spinner Moros I had a 3" x 3/8" x 28" S7 bar spun by a short mag through a 2:1 right angle box. Besides a bit of mushrooming at the tip, I never had a problem with the bar failing.Quote:
Originally Posted by overkill
A few videos:
https://www.youtube.com/watch?v=BO8XSH21tzU
https://www.youtube.com/watch?v=SK1zZOtwIuk
https://www.youtube.com/watch?v=HoHERDQgZwo
Great videos Mike! Are they from Motorama? I am seriously thinking about going next year.
Love the overhead and same about wanting to go to Motorama!
Yeah, those are from Motorama.
Nick is right. We want to shape the disc after it has been cut so using Hardox is out as you can't machine it.
It also seems that S7 is hard to come by in the UK. We have contacted around 8 different suppliers and only 1 said they could source it if we needed it where as most can get H13. That said we only need it once and we have almost a whole year to get it done.
That is a good point about the hardening. I suspect most companies in the UK will know how to treat H13 and not S7 even if they are very similar.
And Motorama is on my list too. I was eye balling Moros as the coire design of Binky at one point.
There is a Euro equivalent to S7 named W-nr 1.2357. I also found some alternate names that might be used in Europe: ASTM A597, ASTM A681, UNS T41907
Ah yes, that long numbered one. My dad found that the other day but we couldn't find a datasheet on it.
Hardox can be machined. The 450 I can do in my own workshop. Not friendly for the tools, and HSS cutters are for the garbagecan after the work.
The 650 can be machined with high end machines and cutters, and if that ain't good enough, spark erosion is another option.
And, if the design doesn't fit the materiaal, redesign is fairly cheap.
You could get the KE back with a hardox disc quite easily. You get say 12mm thick 650 cut to form the main disc, spokes, and teeth, with a bolt pattern around the rim, and then ~5mm steel of any kind, and put a circle of it around the outside on either side, bolted on. The result is a strong, cheapish disc with massive KE and a plenty tough enough tooth. I will likely experiment with that sort of thing, maybe for next year.
540's beater was waterjet from 25mm hardox... the edges did taper slightly but still good enough for a robot... im told some waterjet companies have a pivoting jet to compensate for the taper if your bothered.