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kapps
01-26-2009, 04:28 PM
I'd like to have something cleared up regarding the manufacturing processes and cost report. How do you report a component such as a wheel hub or upright that was cnc cut for our car but in a real manufacturing environment, would be cast and then finish machined? Casting isn't exactly a suitable process for making a 'prototype' part (at least for teams without big money or backing from a casting company). I've spoken with some of our alumni and the answers seem split. So can you report a fully machined part as predominantly cast? Thanks.

kapps
01-26-2009, 04:28 PM
I'd like to have something cleared up regarding the manufacturing processes and cost report. How do you report a component such as a wheel hub or upright that was cnc cut for our car but in a real manufacturing environment, would be cast and then finish machined? Casting isn't exactly a suitable process for making a 'prototype' part (at least for teams without big money or backing from a casting company). I've spoken with some of our alumni and the answers seem split. So can you report a fully machined part as predominantly cast? Thanks.

Bill Riley
01-26-2009, 04:44 PM
This is explicit in the new rules:

3.6.1 The Cost Report must:
D. Be based on the actual manufacturing technique used on the prototype, e.g. cast parts on the prototype must be cost as cast, and fabricated parts as fabricated, etc.

kapps
01-26-2009, 07:12 PM
Ah, thanks for the quick reply.

kapps
01-27-2009, 09:20 AM
One more quick question. I don't see any cnc machining listed in the process table. Last year, it was in the rules at $70/hr but it's not there anymore. Am I missing something obvious?

Bill Riley
01-27-2009, 04:04 PM
The focus in the new rules is to only distinguish costs between things that a judge can verify while standing at your car. That is why all steel costs the same for example. It isn't as accurate but the judge won't know if you used mild or 4340 heat treated.

CNC time is the same. Look at the "material removal" processes and you will see the costs for milling, turning, facing, etc. all expressed in terms of volume of material. So a hub that is 3" diameter machined out to be essentially hollow could be verified at the competition or off the drawing you submit with your cost report. No more arguing about whether it is 5 minutes of machining or 30 minutes because it is 100mm^3.

kapps
01-27-2009, 06:46 PM
Cool, thats what I was thinking. I guess it also means that manual milling and cnc milling all costs the same now.

Bill Riley
01-28-2009, 05:14 PM
Yes, there is no difference or differentiation between manual and CNC.

Johan Andersson
03-31-2009, 12:55 PM
Hi
I have a question regarding the manufacturing processes.
Have I interpret it right that there are no difference in rough and finished machining in to the cost report, that is: we only have to state one machining operation (milling or turning all stated as machining) and multiply the machining cost with the total amount of material that been cut from the raw material. regardless if the cutting have been done as a rough or finished cutting?

Example
Old version:
cut off by rough cutting 300cm^3, cost 0,04 $/cm^3 , 300*0,04= 12$
cut off by finished cutting 100cm^3, cost 0,04 $/cm^3, 100*0,04 = 4$

New version (as I interpret it):
cut off by cutting 400cm^3, cost 0,04 $/cm^3, 400*0,04=16$

Hope that you can make this clear for us!