15-06-2018, 02:34 PM
(This post was last modified: 15-06-2018, 02:41 PM by Austin in the Shed.
Edit Reason: add content
)
Making parts from stock bar is pretty easy,producing a part from a pattern not so.
Firstly you need a pattern,cost.
Is it accurate enough , and designed so that the foundry can use it.
You have to carefully store them.
Foundry has not got to loose or damage parts of it.
Foundry has to produce a good casting.
Parts have to be cast in the correct/appropriate material and possibly heat treated without distortion.
The machinist has to get the best out of the casting,otherwise it could be a pile of scrap.The machining has to be accurate,ie crank cam centres to c.002",bearing bores c.0005"
More so with a crankcase,it would be easy to come out of the side with say an oil gallery.
Even with the best castings you can still get locallsed areas of porosity or a blow hole,no two are the same.
Any of the problems above and it's no good.
Not many people will buy a new crankcase while second hand ones are available.
Firstly you need a pattern,cost.
Is it accurate enough , and designed so that the foundry can use it.
You have to carefully store them.
Foundry has not got to loose or damage parts of it.
Foundry has to produce a good casting.
Parts have to be cast in the correct/appropriate material and possibly heat treated without distortion.
The machinist has to get the best out of the casting,otherwise it could be a pile of scrap.The machining has to be accurate,ie crank cam centres to c.002",bearing bores c.0005"
More so with a crankcase,it would be easy to come out of the side with say an oil gallery.
Even with the best castings you can still get locallsed areas of porosity or a blow hole,no two are the same.
Any of the problems above and it's no good.
Not many people will buy a new crankcase while second hand ones are available.